MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
________________________________________________________________
Maxim Integrated Products
1
Ordering Information
19-0606; Rev 3; 9/09
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
General Description
The MAX9789/MAX9790 combine a stereo, 2W Class AB
speaker power amplifier with a stereo 100mW
DirectDrive®headphone amplifier in a single device. The
MAX9789/MAX9790 are designed for use with the
Microsoft Windows Vista®operating system and are fully
compliant with Microsoft’s Windows Vista specifications.
The headphone amplifier features Maxim’s DirectDrive
architecture that produces a ground-referenced output
from a single supply to eliminate the need for large DC-
blocking capacitors, as well as save cost, board space,
and component height. A high +90dB PSRR and low
0.002% THD+N ensures clean, low-distortion amplifica-
tion of the audio signal.
Separate speaker and headphone amplifier control
inputs provide independent shutdown of the speaker
and headphone amplifiers, allowing speaker and head-
phone amplifiers to be active simultaneously, if
required. The industry-leading click-and-pop suppres-
sion circuitry reduces audible transients during startup
and shutdown cycles.
The MAX9789 features an internal LDO that can be used
as a clean power supply for a CODEC or other circuits.
The LDO output voltage is set internally at 4.75V or can
be adjusted between 1.21V and 4.75V using a simple
resistive divider. The LDO is protected against thermal
overloads and short circuits while providing 120mA of
continuous output current and can be enabled indepen-
dently of the audio amplifiers.
By disabling the speaker and headphone amplifiers, and
the LDO (for MAX9789), the MAX9789/MAX9790 enter
low-power shutdown mode and draw only 0.3µA.
The MAX9789/MAX9790 operate from a single 4.5V to
5.5V supply and feature thermal-overload and output
short-circuit protection. Devices are specified over the
-40°C to +85°C extended temperature range.
Features
Applications
Note: All devices are specified over the -40°C to +85°C extended
temperature range.
+
Denotes a lead-free/RoHS-compliant package.
*
EP = Exposed pad.
**
Future product—contact factory for availability.
PART
PIN-PACKAGE
INTERNAL LDO
tON (ms)
MAX9789AETJ+
32 TQFN-EP*
Yes 100
MAX9789BETJ+**
32 TQFN-EP*
Yes 25
MAX9789CETJ+
32 TQFN-EP*
Yes 100
MAX9790AETJ+
32 TQFN-EP*
No 100
MAX9790BETJ+**
32 TQFN-EP*
No 25
Simplified Block Diagrams
MAX9789
SPKR_EN
HP_EN
MUTE
GAIN1
GAIN2
SPEAKER SUPPLY
4.5V TO 5.5V
HEADPHONE SUPPLY
3.0V TO 5.5V
LDO
4.5V TO 5.5V
SPKR_INR
SPKR_INL
HP_INR
HP_INL
1.21V TO 4.75V
♦Microsoft Windows Vista Compliant
♦Class AB 2W Stereo BTL Speaker Amplifier
♦100mW DirectDrive Headphone Amplifier
Eliminates Costly, Bulky DC-Blocking Capacitors
♦Excellent RF Immunity
♦Integrated 120mA LDO (MAX9789)
♦High +90dB PSRR, Low 0.002% THD+N
♦Low-Power Shutdown Mode
♦Click-and-Pop Suppression
♦Short-Circuit and Thermal-Overload Protection
♦Available in 32-Pin Thin QFN (5mm x 5mm x
0.8mm) Package
Notebook Computers
Tablet PCs
Portable Multimedia Players
Windows Vista is a registered trademark of Microsoft Corp.
Pin Configurations appear at end of data sheet.
Simplified Block Diagrams continued at end of data sheet.
DirectDrive is a registered trademark of Maxim Integrated
Products, Inc.
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VDD = PVDD = CPVDD = HPVDD = HP_EN = VLDO_EN (MAX9789 only) = +5V, VGND = VPGND = VCPGND = SPKR_EN = VLDO_SET
(MAX9789 only) = 0V, ILDO_OUT (MAX9789 only) = 0, C1 = C2 = CBIAS = 1µF. RL= ∞, unless otherwise specified, VGAIN1 = 0,
VGAIN2 = 5V (AVSP = 10dB, AVHP = 3.5dB), TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
Supply Voltage (VDD, PVDD, HPVDD,
CPVDD to GND)..................................................-0.3V to +6.0V
GND to PGND, CPGND ......................................................±0.3V
CPVSS, C1N, VSS to GND......................................-6.0V to +0.3V
HPR, HPL to GND ...............................................................±3.0V
Any Other Pin .............................................-0.3V to (VDD + 0.3V)
Duration of OUT_+, OUT_- Short Circuit
to GND or PVDD ......................................................Continuous
Duration of Short Circuit between OUT_+, OUT_-
and LDO_OUT.........................................................Continuous
Duration of Short Circuit between HPR, HPL and GND,
VSS or HPVDD..........................................................Continuous
Continuous Current (PVDD, OUT_+, OUT_-, PGND).............1.7A
Continuous Current (CPVDD, C1N, C1P, CPVSS, PVSS,
VDD, HPVDD, LDO_OUT, HPR, HPL) .............................850mA
Continuous Input Current (all other pins) .........................±20mA
Continuous Power Dissipation (TA= +70°C)
32-Pin Thin QFN Single-Layer Board
(derate 18.6mW/°C above +70°C)..............................1489mW
θJA...........................................................................53.7°C/W
θJC...........................................................................19.9°C/W
32-Pin Thin QFN Multilayer Board
(derate 24.9 mW/°C above +70°C).............................1990mW
θJA...........................................................................40.2°C/W
θJC...........................................................................19.9°C/W
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
GENERAL
Supply Voltage VDD, PVDD Guaranteed by PSRR and LDO Line
Regulation Tests 4.5 5.5 V
Headphone Supply Voltage CPVDD,
HPVDD Guaranteed by PSRR Test 3.0 5.5 V
SPKR_EN HP_EN
1 (MAX9789) 0 (MAX9789) 0.1 0.4 mA
1 (MAX9790) 0 (MAX9790) 0.3 6 µA
11 713
0 0 14 29
Quiescent Current IDD
0 1 18 40
mA
Shutdown Current ISHDN SPKR_EN = VDD, HP_EN = LDO_EN = GND 0.3 6 µA
Bias Voltage VBIAS 1.7 1.8 1.9 V
MAX9789A/MAX9789C/MAX9790A 100
Shutdown to Full Operation tSON MAX9789B/MAX9790B 25 ms
Gain Switching Time tSW 10 µs
Channel-to-Channel Gain
Tracking ±0.1 dB
SPEAKER AMPLIFIER
RL = 4Ω2
Output Power POUT THD+N = 1%, f = 1kHz,
TA = +25°C RL = 8Ω1W
RL = 8Ω, POUT = 1W, f = 1kHz 0.002
Total Harmonic Distortion Plus
Noise THD+N RL = 4Ω, POUT = 1W, f = 1kHz 0.004 %
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7 using a four-
layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VDD = PVDD = CPVDD = HPVDD = HP_EN = VLDO_EN (MAX9789 only) = +5V, VGND = VPGND = VCPGND = SPKR_EN = VLDO_SET
(MAX9789 only) = 0V, ILDO_OUT (MAX9789 only) = 0, C1 = C2 = CBIAS = 1µF. RL= ∞, unless otherwise specified, VGAIN1 = 0,
VGAIN2 = 5V (AVSP = 10dB, AVHP = 3.5dB), TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
VDD = 4.5V to 5.5V, TA = +25°C 72 90
f = 1kHz, 200mVP-P (Note 4) 70
Power-Supply Rejection Ratio PSRR
f = 10kHz, 200mVP-P (Note 4) 50
dB
GAIN1 GAIN2
00 6
01 10
1 0 15.6
Voltage Gain AV
1 1 21.6
dB
Measured at speaker amplifier inputs
GAIN1 GAIN2
00 80
01 65
10 45
Input Impedance RIN
11 25
kΩ
±1 ±15
Output Offset Voltage VOS
Measured between
OUT_+ and OUT_-,
TA = +25°C MAX9789C ±1 ±25
mV
Into shutdown -50
Click-and-Pop Level KCP
RL = 8Ω, peak voltage,
A-weighted, 32 samples
per second (Notes 3, 4) Out of shutdown -50
dBV
A-weighted 102
Signal-to-Noise Ratio SNR RL = 8Ω, POUT = 1W f = 22Hz to 22kHz 99 dB
Noise VnBW = 22Hz to 22kHz 30 µVRMS
Capacitive-Load Drive CLNo sustained oscillations 200 pF
Crosstalk
L to R, R to L, RL = 8Ω, FS = 0.707VRMS,
VOUT = 70.7nVRMS, 20kHz AES17,
BW = 20Hz to 20kHz
-70 dB
Slew Rate SR 1.4 V/µs
HEADPHONE AMPLIFIER
RL = 16Ω100
Output Power POUT THD+N = 1%, f =
1kHz, TA = +25°C RL = 32Ω55 mW
RL = 32Ω, FS = 0.300VRMS,
VOUT = 210mVRMS, 20kHz AES17,
BW = 20Hz to 20kHz
-77 dB FS
RL = 32Ω, POUT = 40mW, f = 1kHz 0.02
RL = 16Ω, POUT = 60mW, f = 1kHz 0.03
%
Total Harmonic Distortion Plus
Noise THD+N
RL = 10kΩ, FS = 0.707VRMS,
VOUT = 500mVRMS, 20kHz AES17,
BW = 20Hz to 20kHz
-94 dB FS
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(VDD = PVDD = CPVDD = HPVDD = HP_EN = VLDO_EN (MAX9789 only) = +5V, VGND = VPGND = VCPGND = SPKR_EN = VLDO_SET
(MAX9789 only) = 0V, ILDO_OUT (MAX9789 only) = 0, C1 = C2 = CBIAS = 1µF. RL= ∞, unless otherwise specified, VGAIN1 = 0,
VGAIN2 = 5V (AVSP = 10dB, AVHP = 3.5dB), TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
HPVDD = 3V to 5.5V, TA = +25°C 70 95
f = 1kHz, VRIPPLE = 200mVP-P (Note 4) 84
Power-Supply Rejection Ratio PSRR
f = 10kHz, VRIPPLE = 200mVP-P (Note 4) 63
dB
Voltage Gain AV3.5 dB
Input Impedance RIN Measured at headphone amplifier inputs 20 40 80 kΩ
±2 ±7
Output Offset Voltage VOS TA = +25°C MAX9789C ±2 ±10 mV
Into shutdown -60
Click-and-Pop Level KCP
RL = 32Ω, peak voltage,
A-weighted, 32 samples
per second (Notes 3, 4) Out of shutdown -60
dBV
RL = 32Ω, f = 1kHz, A-weighted,
FS = 0.300VRMS, VOUT = 300µVRMS 89
Dynamic Range DR RL = 10kΩ, f = 1kHz, A-weighted,
FS = 0.707VRMS, VOUT = 707µVRMS 97
dB FS
22Hz to 22kHz 100
Signal-to-Noise Ratio SNR RL = 32Ω,
POUT = 60mW A-weighted 103 dB
Noise VnBW = 22Hz to 22kHz 12 µVRMS
Capacitive-Load Drive CLNo sustained oscillations 200 pF
RL = 32Ω,
FS = 0.300VRMS,
VOUT = 30mVRMS
-74
Crosstalk
L to R, R to L,
20kHz AES17
BW = 20Hz to 20kHz RL = 10kΩ,
FS = 0.707VRMS,
VOUT = 70.7mVRMS
-77
dB
Slew Rate SR 0.4 V/µs
500 550 625
Charge-Pump Frequency fOSC MAX9789C 475 550 625 kHz
LOW-DROPOUT LINEAR REGULATOR
Regulator Input Voltage Range VDD Inferred from line regulation 4.5 5.5 V
IOUT = 0mA 0.1 0.4
Ground Current IGND IOUT = 120mA -40 mA
Output Current IOUT 120 mA
Crosstalk VOUT = 4.75V, IOUT = 0mA, f = 1kHz,
speaker POUT = 2W, speaker RL = 4Ω-95 dB
±1.5
Fixed Output Voltage Accuracy IOUT = 1mA MAX9789C ±3.0 %
Adjustable Output Voltage Range 1.21 4.75 V
1.18 1.21 1.23
LDO_SET Reference Voltage VSET MAX9789C 1.18 1.21 1.25 V
LDO_SET Dual-Mode Threshold 200 mV
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
_______________________________________________________________________________________ 5
Note 2: All devices are 100% production tested at room temperature. All temperature limits are guaranteed by design.
Note 3: Specified at room temperature with an 8Ωresistive load connected across BTL output for speaker amplifier. Specified at
room temperature with a 32Ωresistive load connected between HPR, HPL, and GND for headphone amplifier. Speaker and
headphone mode transitions are controlled by SPKR_EN and HP_EN control pins, respectively.
Note 4: Amplifier inputs AC-coupled to GND.
Note 5: Maximum value is due to test limitations.
Note 6: VLDO_OUT = VLDO_OUTNOMINAL - 2%.
ELECTRICAL CHARACTERISTICS (continued)
(VDD = PVDD = CPVDD = HPVDD = HP_EN = VLDO_EN (MAX9789 only) = +5V, VGND = VPGND = VCPGND = SPKR_EN = VLDO_SET
(MAX9789 only) = 0V, ILDO_OUT (MAX9789 only) = 0, C1 = C2 = CBIAS = 1µF. RL= ∞, unless otherwise specified, VGAIN1 = 0,
VGAIN2 = 5V (AVSP = 10dB, AVHP = 3.5dB), TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
LDO_SET Input Bias Current
(Note 5) ISET ±20 ±500 nA
IOUT = 50mA 25 50
Dropout Voltage (Note 6) VDO
VOUT = 4.75V (fixed
output operation),
TA = +25°C IOUT = 120mA 75 150
mV
Current Limit ILIM 300 mA
Startup Time 20 µs
Line Regulation VIN = 4.5V to 5.5V, LDO_OUT = 2.5V,
ILDO_OUT = 1mA -4.8 +0.8 +4.8 mV/V
Load Regulation VLDO_OUT = 4.75V,
1mA < ILDO_OUT < 120mA 0.2 mV/mA
f = 1kHz 59
Ripple Rejection VRIPPLE = 200mVP-P
ILDO_OUT = 10mA f = 10kHz 42 dB
Output Voltage Noise 20Hz to 22kHz, CLDO_OUT = 2 x 1µF,
ILDO_OUT = 120mA 125 µVRMS
DIGITAL INPUTS (SPKR_EN, HP_EN, MUTE, GAIN1, GAIN2, LDO_EN (MAX9789 Only))
Input-Voltage High VINH 2V
Input-Voltage Low VINL 0.8 V
Input Bias Current ±1 µA
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
6 _______________________________________________________________________________________
Typical Operating Characteristics
(VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, VGND = VPGND = VCPGND = VLDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1µF. RL=
∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA= +25°C,
unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.)
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (HEADPHONE MODE)
MAX9789 toc01
FREQUENCY (Hz)
THD+N (dB FS)
10k1k100
-100
-90
-80
-70
-60
-110
10 100k
FS = 0.707VRMS
VOUT = -3dB FS
RL = 10kΩ
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (HEADPHONE MODE)
MAX9789 toc02
FREQUENCY (Hz)
THD+N (dB FS)
10k1k100
-90
-80
-70
-60
-100
10 100k
HPVDD = 3V
FS = 0.707VRMS
VOUT = -3dB FS
RL = 10kΩ
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT VOLTAGE (HEADPHONE MODE)
MAX9789 toc03
OUTPUT VOLTAGE (VRMS)
THD+N (%)
1.51.00.5
0.01
0.1
1
10
0.001
0 2.0
RL = 10kΩ
fIN = 20Hz
fIN = 10kHz
fIN = 1kHz
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT VOLTAGE (HEADPHONE MODE)
MAX9789 toc04
OUTPUT VOLTAGE (VRMS)
THD+N (%)
1.51.00.5
0.01
0.1
1
10
0.001
0 2.0
HPVDD = 3V
RL = 10kΩ
fIN = 20Hz
fIN = 1kHz
fIN = 10kHz
CROSSTALK
vs. FREQUENCY (HEADPHONE MODE)
MAX9789 toc05
FREQUENCY (Hz)
CROSSTALK (dB)
10k1k100
-80
-90
-60
-40
-20
-70
-50
-30
-10
0
-100
10 100k
FS = 0.707VRMS
VOUT = -20dB FS
RL = 10kΩ
LEFT TO RIGHT
RIGHT TO LEFT
HEADPHONE OUTPUT SPECTRUM
MAX9789 toc06
FREQUENCY (Hz)
CROSSTALK (dB)
15k10k5k
-80
-90
-60
-40
-20
-70
-50
-30
-10
0
-140
-100
-110
-120
-130
0 20k
FS = 0.300VRMS
VOUT = -60dB FS
RL = 10kΩ
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (SPEAKER MODE)
MAX9789 toc07
FREQUENCY (Hz)
THD+N (dB FS)
1k100
-90
-95
-85
-80
-75
-100
10 100k10k
VOUT = -3dB FS
FS = 0.707VRMS
RL = 3Ω
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (SPEAKER MODE)
MAX9789 toc08
FREQUENCY (Hz)
THD+N (dB FS)
1k100
-90
-95
-85
-80
-75
-100
10 100k10k
VOUT = -3dB FS
FS = 0.707VRMS
RL = 4Ω
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (SPEAKER MODE)
MAX9789 toc09
FREQUENCY (Hz)
THD+N (dB FS)
1k100
-90
-100
-95
-105
-85
-80
-75
-110
10 100k10k
VOUT = -3dB FS
FS = 0.707VRMS
RL = 8Ω
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
_______________________________________________________________________________________
7
Typical Operating Characteristics (continued)
(VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, VGND = VPGND = VCPGND = VLDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1µF. RL=
∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA= +25°C,
unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.)
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (SPEAKER MODE)
MAX9789 toc10
OUTPUT POWER (W)
THD+N (%)
1.51.00.5
0.01
0.1
1
10
0.001
0 3.02.0 2.5
RL = 3Ω
fIN = 10kHz
fIN = 20Hz fIN = 1kHz
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (SPEAKER MODE)
MAX9789 toc11
OUTPUT POWER (W)
THD+N (%)
1.51.00.5
0.01
0.1
1
10
0.001
0 2.52.0
RL = 4Ω
fIN = 10kHz
fIN = 20Hz fIN = 1kHz
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (SPEAKER MODE)
MAX9789 toc12
OUTPUT POWER (W)
THD+N (%)
1.00.5
0.01
0.1
1
10
0.001
01.5
RL = 8Ω
fIN = 10kHz
fIN = 20Hz
fIN = 1kHz
CROSSTALK
vs. FREQUENCY (SPEAKER MODE)
MAX9789 toc13
FREQUENCY (Hz)
CROSSTALK (dB)
10k1k100
-80
-60
-40
-20
0
-100
-70
-50
-30
-10
-90
10 100k
FS = 0.707VRMS
VOUT = -20dB FS
RL = 8Ω
LEFT TO RIGHT
RIGHT TO LEFT
SPEAKER OUTPUT SPECTRUM
FREQUENCY (Hz)
CROSSTALK (dB)
MAX9789 toc14
0 5k 10k 15k 20k
-140
-130
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
FS = 0.707VRMS
VOUT = -60dB FS
RL = 8Ω
OUTPUT POWER vs. LOAD RESISTANCE
(SPEAKER MODE)
RL (Ω)
OUTPUT POWER (W)
MAX9789 toc15
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
1 10 100
fIN = 1kHz
THD+N = 1%
THD+N = 10%
POWER DISSIPATION PER CHANNEL
vs. OUTPUT POWER (SPEAKER MODE)
OUTPUT POWER PER CHANNEL (W)
POWER DISSIPATION PER CHANNEL (W)
MAX9789 toc16
0 0.5 1.0 1.5 2.0
0
0.25
0.50
0.75
1.00
1.25
1.50
RL = 8Ω
RL = 4Ω
fIN = 1kHz
POWER-SUPPLY REJECTION RATIO
(SPEAKER MODE)
FREQUENCY (Hz)
PSRR (dB)
MAX9789 toc17
10 100 1k 10k 100k
100
-90
-70
-80
-40
-50
-60
-30
-20
-10
0
VRIPPLE = 200mVP-P
OUTPUT REFERRED
SPEAKER SHUTDOWN WAVEFORM
MAX9789 toc20
20ms/div
2V/div
5V/div
100mV/div
OUT_+ AND OUT_-
OUT_+ - OUT_-
SPKR_EN
Typical Operating Characteristics (continued)
(VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, VGND = VPGND = VCPGND = VLDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1µF. RL=
∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA= +25°C,
unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.)
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
8 _______________________________________________________________________________________
SPEAKER STARTUP WAVEFORM
MAX9789 toc18
20ms/div
2V/div
OUT_+ AND OUT_-
OUT_+ - OUT_-
5V/div
SPKR_EN
100mV/div
MAX9789A/MAX9789C/MAX9790A
SPEAKER STARTUP WAVEFORM
MAX9789 toc19
20ms/div
OUT_+ AND OUT_-
2V/div
OUT_+ - OUT_-
100mV/div
SPKR_EN
5V/div
MAX9789B/MAX9790B
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (HEADPHONE MODE)
MAX9789 toc21
FREQUENCY (Hz)
THD+N (dB FS)
10k1k100
-105
-95
-85
-75
-65
-110
-100
-90
-80
-70
10 100k
FS = 0.300VRMS
RL = 32Ω
VOUT = -3dB FS
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (HEADPHONE MODE)
MAX9789 toc22
FREQUENCY (Hz)
THD+N (dB FS)
10k1k100
-105
-95
-85
-75
-65
-110
-100
-90
-80
-70
10 100k
HPVDD = 3V
FS = 0.300VRMS
RL = 32Ω
VOUT = -3dB FS
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (HEADPHONE MODE)
MAX9789 toc23
FREQUENCY (Hz)
THD+N (dB FS)
10k1k100
-105
-95
-85
-75
-65
-110
-100
-90
-80
-70
10 100k
FS = 0.300VRMS
RL = 16Ω
VOUT = -3dB FS
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (HEADPHONE MODE)
MAX9789 toc24
FREQUENCY (Hz)
THD+N (dB FS)
10k1k100
-105
-95
-85
-75
-65
-110
-100
-90
-80
-70
10 100k
HPVDD = 3V
FS = 0.300VRMS
RL = 16Ω
VOUT = -3dB FS
MAX9789/MAX9790
HEADPHONE OUTPUT SPECTRUM
MAX9789 toc30
FREQUENCY (kHz)
AMPLITUDE (dB)
15105
-80
-60
-40
-20
0
-140
-70
-50
-30
-10
-100
-120
-90
-110
-130
020
FS = 0.707VRMS
VOUT = -60dB FS
RL = 32Ω
OUTPUT POWER vs. LOAD RESISTANCE
(HEADPHONE MODE)
RL (Ω)
OUTPUT POWER (mW)
MAX9789 toc31
0
50
100
150
10 100 1000
THD+N = 1%
THD+N = 10%
fIN = 1kHz
OUTPUT POWER vs. LOAD RESISTANCE
(HEADPHONE MODE)
RL (Ω)
OUTPUT POWER (mW)
MAX9789 toc32
0
50
100
10 100 1000
HPVDD = 3V
fIN = 1kHz
THD+N = 1%
THD+N = 10%
Typical Operating Characteristics (continued)
(VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, VGND = VPGND = VCPGND = VLDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1µF. RL=
∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA= +25°C,
unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.)
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (HEADPHONE MODE)
MAX9789 toc26
OUTPUT POWER (mW)
THD+N (%)
604020
0.1
10
0.01
1
010080
RL = 32Ω
f = 1kHz
f = 10kHz
f = 20Hz
CROSSTALK
vs. FREQUENCY (HEADPHONE MODE)
MAX9789 toc29
FREQUENCY (Hz)
CROSSTALK (dB)
10k1k100
-80
-60
-40
-20
0
-110
-70
-50
-30
-10
-90
-100
10 100k
FS = 0.300VRMS
VOUT = -20dB FS
RL = 32Ω
LEFT TO RIGHT
RIGHT TO LEFT
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
_______________________________________________________________________________________
9
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (HEADPHONE MODE)
MAX9789 toc25
OUTPUT POWER (mW)
THD+N (%)
15010050
0.1
10
0.01
1
0200
RL = 16Ω
f = 20Hz
f = 10kHz
f = 1kHz
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (HEADPHONE MODE)
MAX9789 toc27
OUTPUT POWER (mW)
THD+N (%)
10050
0.1
10
0.01
1
0150
HPVDD = 3V
RL = 16Ω
f = 1kHz
f = 10kHz
f = 20Hz
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (HEADPHONE MODE)
MAX9789 toc28
OUTPUT POWER (mW)
THD+N (%)
604020
0.1
10
0.01
1
010080
HPVDD = 3V
RL = 32Ω
f = 20Hz
f = 10kHz
f = 1kHz
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
10 ______________________________________________________________________________________
POWER DISSIPATION vs. OUTPUT POWER
(HEADPHONE MODE)
OUTPUT POWER PER CHANNEL (mW)
POWER DISSIPATION PER CHANNEL (mW)
MAX9789 toc33
0 25 50 75 100 125
0
25
50
75
100
125
150
175
200
225
250
275
300
RL = 32Ω
RL = 16Ω
POWER DISSIPATION PER CHANNEL
vs. OUTPUT POWER (HEADPHONE MODE)
OUTPUT POWER PER CHANNEL (mW)
POWER DISSIPATION PER CHANNEL (mW)
MAX9789 toc34
0 20406080
0
25
50
75
100
125
RL = 32Ω
RL = 16Ω
HPVDD = 3V
HEADPHONE OUTPUT POWER vs. HPVDD
HPVDD (V)
HEADPHONE OUTPUT POWER (mW)
MAX9789 toc35
3.0 3.5 4.0 4.5 5.0
0
25
50
75
100
125
THD+N = 1%
fIN = 1kHz
RL = 32Ω
RL = 16Ω
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY (HEADPHONE MODE)
FREQUENCY (Hz)
PSRR (dB)
MAX9789 toc36
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10 100 1k 10k 100k
VRIPPLE = 200mVP-P
OUTPUT REFERRED
HEADPHONE STARTUP WAVEFORM
MAX9789 toc37
20ms/div
HP_
500mV/div
HP_EN
5V/div
MAX9789A/MAX9789C/MAX9790A
HEADPHONE STARTUP WAVEFORM
MAX9789 toc38
20ms/div
HP_EN
5V/div
HP_
500mV/div
MAX9789B/MAX9790B
Typical Operating Characteristics (continued)
(VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, VGND = VPGND = VCPGND = VLDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1µF. RL=
∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA= +25°C,
unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.)
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
______________________________________________________________________________________
11
Typical Operating Characteristics (continued)
(VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, VGND = VPGND = VCPGND = VLDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1µF. RL=
∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA= +25°C,
unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.)
HEADPHONE SHUTDOWN WAVEFORM
MAX9789 toc39
20ms/div
HP_
HP_EN
5V/div
500mV/div
SUPPLY CURRENT vs. SUPPLY VOLTAGE
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
MAX9789 toc40
4.50 4.75 5.00 5.25 5.50
-5
0
5
10
15
20
SPKR_EN = 0
HP_EN = 0
SPKR_EN = 0
HP_EN = 1
SPKR_EN = 1
HP_EN = 0
SPKR_EN = 1
HP_EN = 1
SHUTDOWN CURRENT vs. SUPPLY VOLTAGE
SUPPLY VOLTAGE (V)
SHUTDOWN CURRENT (μA)
MAX9789 toc41
4.50 4.75 5.00 5.25 5.50
0
0.1
0.2
0.3
SPKR_EN = 5V
HP_EN = 0
LDO_EN = 0 (MAX9789)
LDO OUTPUT VOLTAGE ACCURACY
vs. ILOAD
ILOAD (mA)
LDO OUTPUT VOLTAGE ACCURACY (%)
MAX9789 toc42
0 25 50 75 100 125 150
-2.0
-1.5
-1.0
-0.5
0
0.5
1.0
1.5
2.0
VLDO_OUT = 4.75V
LDO OUTPUT VOLTAGE ACCURACY
vs. AMPLIFIER OUTPUT POWER
AMPLIFIER OUTPUT POWER (W)
LDO OUTPUT VOLTAGE ACCURACY (%)
MAX9789 toc43
0 0.5 1.0 1.5 2.0 2.5 3.0
-0.10
-0.05
0
0.05
0.10
VLDO_OUT = 4.75V
ILDO_OUT = 0A
LDO OUTPUT VOLTAGE ACCURACY
vs. TEMPERATURE
TEMPERATURE (°C)
LDO OUTPUT VOLTAGE ACCURACY (%)
MAX9789 toc44
-40 -15 10 35 60 85
-2.0
-1.5
-1.0
-0.5
0
0.5
1.0
1.5
2.0
ILDO_OUT = 1mA
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
12 ______________________________________________________________________________________
LINE-TRANSIENT RESPONSE
MAX9789 toc48
1ms/div
LDO_OUT
(AC-COUPLED)
20mV/div
VDD
1V/div
5.5V
4.5V
LDO LOAD-TRANSIENT RESPONSE
MAX9789 toc49
20ms/div
AC-COUPLED
VLDO_OUT
10mV/div
ILDO_OUT
15mA/div
LDO SHUTDOWN RESPONSE
MAX9789 toc50
200ms/div
VLDO_OUT
2V/div
LDO_EN
2V/div
ILOAD = 0mA
LDO CROSSTALK vs. FREQUENCY
FREQUENCY (Hz)
CROSSTALK (dB)
MAX9789 toc51
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
10 100 1k 10k 100k
VLDO_OUT = 4.75V
POUT = 2W
RL = 4Ω
IOUT = 0mA
LEFT SPEAKER TO LDO
RIGHT SPEAKER TO LDO
Typical Operating Characteristics (continued)
(VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, VGND = VPGND = VCPGND = VLDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1µF. RL=
∞, unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA= +25°C,
unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.)
DROPOUT VOLTAGE vs. ILOAD
MAX9789 toc45
ILOAD (mA)
DROPOUT VOLTAGE (mV)
125100755025
10
20
30
40
50
60
70
80
90
100
0
0150
VLDO_OUT = 4.75V
VLDO_OUT = 3.3V
RIPPLE REJECTION vs. FREQUENCY
MAX9789 toc46
FREQUENCY (Hz)
RIPPLE REJECTION (dB)
10k1k100
-80
-70
-60
-50
-40
-30
-20
-10
0
-90
10 100k
VLDO_OUT = 4.75V
VRIPPLE = 200mVP-P
IOUT = 10mA
OUTPUT REFERRED
VLDO_OUT = 3.3V
OUTPUT NOISE vs. FREQUENCY
MAX9789 toc47
FREQUENCY (Hz)
OUTPUT NOISE (μV√Hz)
10k1k100
0.1
1
10
0.01
10 100k
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
______________________________________________________________________________________ 13
Pin Description
PIN
MAX9789 MAX9790
NAME FUNCTION
1 — LDO_SET Regulator Feedback Input. Connect to GND for 4.75V fixed output. Connect to a resistor-
divider for adjustable output. See Figure 1.
2 2 SPKR_INR Right-Channel Speaker Amplifier Input
3 3 SPKR_INL Left-Channel Speaker Amplifier Input
4 — LDO_EN LDO Enable. Connect LDO_EN to VDD to enable the LDO.
5, 21 5, 21 PGND Power Ground. Star-connect to GND.
6 6 OUTL+ Left-Channel Speaker Amplifier Output, Positive Phase
7 7 OUTL- Left-Channel Speaker Amplifier Output, Negative Phase
8, 18 8, 18 PVDD Speaker Amplifier Power-Supply Input. Bypass with a 0.1µF capacitor to PGND.
9 9 CPVDD Charge-Pump Power Supply. Connect a 1µF capacitor between CPVDD and PGND.
10 10 C1P Charge-Pump Flying Capacitor Positive Terminal. Connect a 1µF capacitor between C1P
to C1N.
11 11 CPGND Charge-Pump Ground. Connect directly to PGND plane.
12 12 C1N Charge-Pump Flying Capacitor Negative Terminal. Connect a 1µF capacitor between C1P
to C1N.
13 13 CPVSS Charge-Pump Output. Connect to PVSS.
14 14 PVSS Headphone Amplifier Negative Power Supply. Connect a 1µF capacitor between PVSS and
PGND.
15 15 HPR Right-Channel Headphone Amplifier Output
16 16 HPL Left-Channel Headphone Amplifier Output
17 17 HPVDD Headphone Amplifier Positive Power Supply. Connect a 10µF capacitor between HPVDD
and PGND.
19 19 OUTR- Right-Channel Speaker Amplifier Output, Negative Phase
20 20 OUTR+ Right-Channel Speaker Amplifier Output, Positive Phase
22 22 HP_EN Active-High Headphone Amplifier Enable
23 23 SPKR_EN Active-Low Speaker Amplifier Enable
24 24 BIAS Common-Mode Bias Voltage. Bypass with a 1µF capacitor to GND.
25 25 MUTE Active-Low Mute Enable. Mutes speaker and headphone amplifiers.
26 26 HP_INR Right-Channel Headphone Amplifier Input
27 27 HP_INL Left-Channel Headphone Amplifier Input
28 4, 28 GND Signal Ground. Star-connect to PGND.
29 — LDO_OUT LDO Output. Bypass with two 1µF capacitors to GND.
30 30 VDD
Positive Power Supply and LDO Input (MAX9789). Bypass with one 0.1µF capacitor and
two 1µF capacitors to GND (MAX9789). Bypass with one 0.1µF capacitor and one 1µF
capacitor to GND (MAX9790).
31 31 GAIN1 Speaker Amplifier Gain Select 1
32 32 GAIN2 Speaker Amplifier Gain Select 2
— 1, 29 N.C. No Connection. Not internally connected.
EP EP EP Exposed Paddle. Connect to GND.
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
14 ______________________________________________________________________________________
Detailed Description
The MAX9789/MAX9790 combine a 2W BTL speaker
amplifier with an 100mW DirectDrive headphone amplifi-
er. These devices feature comprehensive click-and-pop
suppression and programmable four-level speaker ampli-
fier gain control. The MAX9789/MAX9790 feature high
+90dB PSRR, low 0.002% THD+N, industry-leading click-
and-pop performance, low-power shutdown mode, and
excellent RF immunity. The MAX9789 incorporates an
integrated LDO that serves as a clean power supply for a
CODEC or other circuits.
The MAX9789/MAX9790 is Microsoft Windows Vista com-
pliant. See Table 1 for a comparison of the Microsoft
Windows Vista premium mobile specifications and
MAX9789/MAX9790 specifications.
The speaker amplifiers use BTL architecture, doubling the
voltage drive to the speakers and eliminating the need for
DC-blocking capacitors. The output consists of two sig-
nals, identical in magnitude, but 180° out of phase.
The headphone amplifiers use Maxim’s DirectDrive
architecture to eliminate the bulky output DC-blocking
capacitors required by traditional headphone ampli-
fiers. A charge pump inverts a positive supply (CPVDD)
to create a negative supply (CPVSS). The headphone
amplifiers operate from these bipolar supplies with their
outputs biased about GND. The benefit of the GND
bias is that the amplifier outputs no longer have a DC
component (typically VDD / 2). This feature eliminates
the large DC-blocking capacitors required with conven-
tional headphone amplifiers to conserve board space
and system cost, as well as improve low-frequency
response.
The MAX9789/MAX9790 feature programmable speak-
er amplifier gain, allowing the speaker gain to be set by
the logic voltages applied to GAIN1 and GAIN2, while
the headphone amplifiers feature a fixed 3.5dB gain.
Both amplifiers feature an undervoltage lockout that
prevents operation from an insufficient power supply
and click-and-pop suppression that eliminates audible
transients on startup and shutdown. The amplifiers
include thermal overload and short-circuit protection.
An additional feature of the speaker amplifiers is that
there is no phase inversion from input to output.
Low-Dropout Linear Regulator
(MAX9789 Only)
The MAX9789’s low-dropout (LDO) linear regulator can
be used to provide a clean power supply to a CODEC
or other circuitry. The LDO can be enabled indepen-
dently of the audio amplifiers. Set LDO_EN = VDD to
enable the LDO or set LDO_EN = GND to disable the
LDO. The LDO is capable of providing up to 120mA
continuous current and features Maxim’s Dual Mode™
feedback, easily enabling a fixed 4.75V output or a
user-adjustable output. When LDO_SET is connected
to GND, the output is internally set to 4.75V. The output
voltage can be adjusted from 1.21V to 4.75V by con-
necting two external resistors as a voltage divider, at
LDO_SET (Figure 1).
Note: THD+N, DYNAMIC RANGE, and CROSSTALK should be measured in accordance with AES-17 audio measurements standards.
Table 1. Windows Premium Mobile Vista Specifications vs. MAX9789/MAX9790
Specifications
DEVICE TYPE REQUIREMENT WINDOWS PREMIUM MOBILE Vista
SPECIFICATIONS
MAX9789/MAX9790
TYPICAL PERFORMANCE
THD+N ≤ -65dB FS
[20Hz, 20kHz]
-94dB FS
[20Hz, 20kHz]
Dynamic range with
signal present
≤ -80dB FS,
A-weighted
-97dB FS,
A-weighted
Analog Line Output
Jack (RL = 10kΩ,
FS = 0.707VRMS)
Line output crosstalk
≤ -50dB
[20Hz, 20kHz]
-77dB
[20Hz, 20kHz]
THD+N ≤ -45dB FS
[20Hz, 20kHz]
-77dB FS
[20Hz, 20kHz]
Dynamic range with
signal present
≤ -60dB FS,
A-weighted
-89dB FS,
A-weighted
Analog Headphone
Out Jack (RL = 32Ω,
FS = 0.300VRMS)Headphone output
crosstalk
≤ -50dB
[20Hz, 20kHz]
-74dB
[20Hz, 20kHz]
Dual Mode is a trademark of Maxim Integrated Products, Inc.
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
______________________________________________________________________________________ 15
The output voltage is set by the following equation:
where VLDO_SET = 1.21V.
To simplify resistor selection:
Since the input bias current at LDO_SET is typically
less than 500nA (max), large resistance values can be
used for R1 and R2 to minimize power consumption
without compromising accuracy. The parallel combina-
tion of R1 and R2 should be less than 1MΩ.
DirectDrive
Conventional single-supply headphone amplifiers have
their outputs biased about a nominal DC voltage
(VDD / 2) for maximum dynamic range. Large coupling
capacitors are needed to block this DC bias from the
headphones. Without these capacitors, a significant
amount of DC current flows to the headphone, resulting
in unnecessary power dissipation and possible dam-
age to both headphone and headphone amplifier.
Maxim’s DirectDrive architecture uses a charge pump
to create an internal negative supply voltage. It allows
the MAX9789/MAX9790 headphone amplifier output to
be biased about GND. With no DC component, there is
no need for the large DC-blocking capacitors. Instead
of two large capacitors (330µF typically required to
meet Vista magnitude response specifications), the
MAX9789/MAX9790 charge pump requires only two
small 1µF ceramic capacitors, conserving board
space, reducing cost, and improving the low-frequency
response of the headphone amplifier.
Previous attempts to eliminate the output coupling
capacitors involved biasing the headphone return
(sleeve) to the DC bias voltage of the headphone
amplifiers. This method raised some issues:
• The sleeve is typically grounded to the chassis.
Using this biasing approach, the sleeve must be iso-
lated from system ground, complicating product
design.
• During an ESD strike, the amplifier’s ESD structures
are the only path to system ground. The amplifier
must be able to withstand the full ESD strike.
• When using the headphone jack as a line out to
other equipment, the bias voltage on the sleeve may
conflict with the ground potential from other equip-
ment, resulting in large ground loop current and
possible damage to the amplifiers.
Low-Frequency Response
In addition to the cost and size disadvantages, the DC-
blocking capacitors limit the low-frequency response of
the amplifier and distort the audio signal:
• The impedance of the headphone load and the DC-
blocking capacitor form a highpass filter with the
-3dB point determined by:
where RLis the impedance of the headphone and
COUT is the value of the DC-blocking capacitor.
• The highpass filter is required by conventional single-
ended, single-supply headphone amplifier to block
the midrail DC component of the audio signal from the
headphones. Depending on the -3dB point, the filter
can attenuate low-frequency signals within the audio
band. Larger values of COUT reduce the attenuation,
but are physically larger, more expensive capacitors.
Figure 2 shows the relationship between the size of
COUT and the resulting low-frequency attenuation.
Note the Vista’s magnitude response specification
calls for a -3dB point at 20Hz at the headphone jack.
The -3dB point at 20Hz for a 32Ωheadphone requires
a 330µF blocking capacitor (Table 2).
fRC
dB L OUT
−=
31
2π
RRVLDO OUT
12 121 1=⎛
⎝
⎜⎞
⎠
⎟
−
_
.
VV R
R
LDO OUT LDO SET__
=+
⎛
⎝
⎜⎞
⎠
⎟
11
2
MAX9789
LDO_OUT
LDO_SET
GND
1μF
R1
R2
1μF
TO HDA
CODEC
Figure 1. Adjustable Output Using External Feedback
Resistors.
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
16 ______________________________________________________________________________________
• The voltage coefficient of the capacitor, the change
in capacitance due to a change in the voltage
across the capacitor, distorts the audio signal. At
frequencies around the -3dB point, this effect is
maximized and the voltage coefficient appears as
frequency-dependent distortion. Figure 3 shows the
THD+N introduced by two different capacitor
dielectrics. Note that around the -3dB point, THD+N
increases dramatically.
• The combination of low-frequency attenuation and fre-
quency-dependent distortion compromises audio
reproduction. DirectDrive improves low-frequency
reproduction in portable audio equipment that empha-
sizes low-frequency effects, such as multimedia lap-
tops, MP3, CD, and DVD players (See Table 2).
Charge Pump
The MAX9789/MAX9790 feature a low-noise charge
pump. The 550kHz switching frequency is well beyond
the audio range, and does not interfere with the audio
signals. The switch drivers feature a controlled switching
speed that minimizes noise generated by switching
transients. Limiting the switching speed of the charge
pump minimizes the di/dt noise caused by the parasitic
bond wire and trace inductance.
BIAS
The MAX9789/MAX9790 feature an internally generat-
ed, power-supply independent, common-mode bias
voltage of 1.8V referenced to GND. BIAS provides both
click-and-pop suppression and sets the DC bias level
for the amplifiers. The BIAS pin should be bypassed to
GND with a 1µF capacitor. No external load should be
applied to BIAS. Any load lowers the BIAS voltage,
affecting the overall performance of the device.
Headphone and Speaker Amplifier Gain
The MAX9789/MAX9790 feature programmable speak-
er amplifier gain, set by the logic voltages applied to
pins GAIN1 and GAIN2. Table 3 shows the logic com-
binations that can be applied to pins GAIN1 and GAIN2
and their affects on the speaker amplifier gain. The
headphone amplifier gain is fixed at 3.5dB.
0
-30
1 10 100 1k 10k 100k
LOW-FREQUENCY ROLLOFF
(RL = 16Ω)
-24
-27
-12
-15
-18
-21
-6
-9
-3
FREQUENCY (Hz)
ATTENUATION (dB)
DirectDrive
330μF
220μF
100μF
33μF
Figure 2. Low-Frequency Attenuation of Common DC-Blocking
Capacitor Values
ADDITIONAL THD+N DUE TO
DC-BLOCKING CAPACITORS
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.001
0.01
0.1
1
10
0.0001
10 100k
TANTALUM
COUT = 100μF
RL = 16Ω
ALUM/ELEC
Figure 3. Distortion Contributed by DC-Blocking Capacitors
MAX9789/MAX9790
GAIN1 GAIN2 SPEAKER MODE
GAIN (dB)
HEADPHONE
MODE GAIN (dB)
0 0 6 3.5
0 1 10 3.5
1 0 15.6 3.5
1 1 21.6 3.5
Table 3. MAX9789/MAX9790
Programmable Gain Settings
f-3dB (Hz)
COUT (µF)
RL = 16ΩRL = 32Ω
22 452 226
33 301 151
100 99 50
220 45 23
330* 30 15
470 21 11
Table 2. Low-Frequency Rolloff
*Vista requirement for 32
Ω
load.
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
______________________________________________________________________________________ 17
Speaker and Headphone
Amplifier Enable
The MAX9789/MAX9790 feature control inputs for the
independent enabling of the speaker and headphone
amplifiers, allowing both to be active simultaneously if
required. Driving SPKR_EN high disables the speaker
amplifiers. Driving HP_EN low independently disables
the headphone amplifiers. For applications that require
only one of the amplifiers to be on at a given time,
SPKR_EN and HP_EN can be tied together allowing a
single logic voltage to enable either the speaker or the
headphone amplifier as shown in Figure 4.
MUTE
The MAX9789/MAX9790 allow for the speaker and
headphone amplifiers to be muted. By driving MUTE
low, both the speaker and headphone amplifiers are
muted. When muted, the speaker outputs remain
biased at VDD / 2.
Shutdown
The MAX9789/MAX9790 feature a low-power shutdown
mode, drawing 0.3µA of supply current. By disabling the
speaker, headphone amplifiers and the LDO (for
MAX9789), the MAX9789/MAX9790 enter low-power
shutdown mode. Set SPKR_EN to VDD and HP_EN and
LDO_EN to GND to disable the speaker amplifiers, head-
phone amplifiers, and LDO, respectively.
Click-and-Pop Suppression
Speaker Amplifier
The MAX9789/MAX9790 speaker amplifiers feature
Maxim’s comprehensive, industry-leading click-and-
pop suppression. During startup, the click-and-pop
suppression circuitry eliminates any audible transient
sources internal to the device. When entering shut-
down, the differential speaker outputs ramp to GND
quickly and simultaneously.
Headphone Amplifier
In conventional single-supply headphone amplifiers, the
output-coupling capacitor is a major contributor of audi-
ble clicks and pops. Upon startup, the amplifier charges
the coupling capacitor to its bias voltage, typically
VDD / 2. Likewise, during shutdown, the capacitor is dis-
charged to GND. A DC shift across the capacitor results,
which in turn, appears as an audible transient at the
headphone. Since the MAX9789/MAX9790 do not require
output-coupling capacitors, no audible transient occurs.
Additionally, the MAX9789/MAX9790 features extensive
click-and-pop suppression that eliminates any audible
transient sources internal to the device. The
startup/shutdown waveform in the
Typical Operating
Characteristics
shows that there are minimal spectral
components in the audible range at the output.
Applications Information
BTL Speaker Amplifiers
The MAX9789/MAX9790 feature speaker amplifiers
designed to drive a load differentially, a configuration
referred to as bridge-tied load (BTL). The BTL configu-
ration (Figure 5) offers advantages over the single-
ended configuration, where one side of the load is
connected to ground. Driving the load differentially
doubles the output voltage compared to a single-
ended amplifier operating under similar conditions. The
doubling of the output voltage yields four times the out-
put power at the load.
Since the differential outputs are biased at mid-supply,
there is no net DC voltage across the load. This elimi-
nates the need for DC-blocking capacitors required for
single-ended amplifiers. These capacitors can be
large, expensive, consume board space, and degrade
low-frequency performance.
MAX9789/MAX9790
SPKR_EN
SINGLE
CONTROL PIN
HP_EN
Figure 4. Enabling Either the Speaker or Headphone Amplifier
with a Single Control Pin
+1 VOUT(P-P)
2 x VOUT(P-P)
VOUT(P-P)
-1
Figure 5. Bridge-Tied Load Configuration
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
18 ______________________________________________________________________________________
Mono Speaker Configuration
The MAX9789 stereo BTL Class AB speaker amplifier
can be configured to drive a mono speaker. Rather
than combining the CODEC’s left- and right-input sig-
nals in a resistive network prior to one channel of the
speaker amplifier input, the transducer itself can be
connected to the BTL speaker amplifier output as
shown in Figure 6. When compared to the resistive net-
work implementation, the configuration in Figure 6 will:
1) Eliminate noise pickup by eliminating the high-
impedance node at the CODEC’s left- and right-
signal mixing point. SNR performance will be
improved as a result.
2) Eliminate gain error by eliminating any resistive
mismatch between the external resistance used to
sum the left and right signals and the MAX9789
internal resistance.
Power Dissipation and Heat Sinking
Under normal operating conditions, the MAX9789/
MAX9790 can dissipate a significant amount of power.
The maximum power dissipation for each package is
given in the
Absolute Maximum Ratings
section under
Continuous Power Dissipation, or can be calculated by
the following equation:
where TJ(MAX) is +150°C, TAis the ambient tempera-
ture, and θJA is the reciprocal of the derating factor in
°C/W as specified in the
Absolute Maximum Ratings
section. For example, θJA for the 32-pin TQFN-EP pack-
age is +40.2°C/W for a multilayer PC board.
Output Power (Speaker Amplifier)
The increase in power delivered by the BTL configura-
tion directly results in an increase in internal power dis-
sipation over the single-ended configuration. The
maximum power dissipation for a given VDD and load is
given by the following equation:
If the power dissipation for a given application exceeds
the maximum allowed for a given package, either reduce
VDD, increase load impedance, decrease the ambient
temperature, or add heat sinking to the device. Large
output, supply, and ground PC board traces improve the
maximum power dissipation in the package.
Thermal-overload protection limits total power dissipa-
tion in these devices. When the junction temperature
exceeds +150°C, the thermal-protection circuitry dis-
ables the amplifier output stage. The amplifiers are
enabled once the junction temperature cools by +15°C.
This results in a pulsing output under continuous ther-
mal-overload conditions as the device heats and cools.
Power Supplies
The MAX9789/MAX9790 have separate supply pins for
each portion of the device, allowing for the optimum
combination of headroom and power dissipation and
noise immunity. The speaker amplifiers are powered
from PVDD. PVDD ranges from 4.5V to 5.5V. The head-
phone amplifiers are powered from HPVDD and PVSS.
HPVDD is the positive supply of the headphone ampli-
fiers and ranges from 3V to 5.5V. PVSS is the negative
supply of the headphone amplifiers. Connect PVSS to
CPVSS. The charge pump is powered by CPVDD.
CPVDD ranges from 3V to 5.5V and should be the same
potential as HPVDD. The charge pump inverts the volt-
age at CPVDD, and the resulting voltage appears at
CPVSS. The internal LDO and the remainder of the
device is powered by VDD.
Component Selection
Supply Bypassing
The MAX9789/MAX9790 have separate supply pins for
each portion of the device, allowing for the optimum
combination of headroom and power dissipation and
noise immunity.
Speaker Amplifier Power-Supply Input (PV
DD
)
The speaker amplifiers are powered from PVDD. PVDD
ranges from 4.5V to 5.5V. Bypass PVDD with a 0.1µF
capacitor to PGND. Note additional bulk capacitance is
required at the device if long input traces between
PVDD and the power source are used.
PV
R
DISS MAX DD
L
()
=22
2
π
PTT
DISSPKG MAX J MAX A
JA
() ()
=−
θ
SPKR_OUTL
SPKR_OUTR
SPKR_INL
SPKR_INR
OUTL+
OUTL-
OUTR+
OUTR-
CODEC CIN1
LINE_OUTR
LINE_OUTL
HP_INL
HP_INR
HPL
HPR
MAX9789
CIN1
CIN2
CIN2
Figure 6. Mono Signal Output Configuration for MAX9789
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
______________________________________________________________________________________ 19
Headphone Amplifier Power-Supply
Input (HPVDD and PVSS)
The headphone amplifiers are powered from HPVDD
and PVSS. HPVDD is the positive supply of the head-
phone amplifiers and ranges from 3.0V to 5.5V. Bypass
HPVDD with a 10µF capacitor to PGND. PVSS is the
negative supply of the headphone amplifiers. Bypass
PVSS with a 1µF capacitor to PGND. Connect PVSS to
CPVSS. The charge pump is powered by CPVDD.
CPVDD ranges from 3.0V to 5.5V and should be the
same potential as HPVDD. Bypass CPVDD with a 1µF
capacitor to PGND. The charge pump inverts the volt-
age at CPVDD, and the resulting voltage appears at
CPVSS. A 1µF capacitor must be connected between
C1N and C1P.
Power Supply and LDO Input (V
DD
)
The internal LDO and the remainder of the device is
powered by VDD. VDD ranges from 4.5V to 5.5V.
Bypass VDD with a 0.1µF capacitor to GND and two
1µF capacitors in parallel to GND. Note additional bulk
capacitance is required at the device if long input
traces between VDD and the power source are used.
Input Filtering
The input capacitor (CIN), in conjunction with the ampli-
fier input resistance (RIN), forms a highpass filter that
removes the DC bias from the incoming signal. The AC-
coupling capacitor allows the amplifier to bias the sig-
nal to an optimum DC level. Assuming zero source
impedance, the -3dB point of the highpass filter is
given by:
RIN is the amplifier’s internal input resistance value
given in the
Electrical Characteristics
. Choose CIN such
that f-3dB is well below the lowest frequency of interest.
Setting f-3dB too high affects the amplifier’s low fre-
quency response. Use capacitors with adequately low
voltage coefficient dielectrics, such as 1206-sized X7R
ceramic capacitors. Capacitors with higher voltage
coefficients result in increased distortion at low fre-
quencies (see Figure 7).
BIAS Capacitor
BIAS is the output of the internally generated DC bias
voltage. The BIAS bypass capacitor, CBIAS improves
PSRR and THD+N by reducing power supply and other
noise sources at the common-mode bias node, and
also generates the clickless/popless, startup/shutdown
DC bias waveforms for the speaker and headphone
amplifiers. Bypass BIAS with a 1µF capacitor to GND.
Charge-Pump Capacitor Selection
Use capacitors with an ESR less than 100mΩfor opti-
mum performance. Low ESR ceramic capacitors mini-
mize the output resistance of the charge pump. For
best performance over the extended temperature
range, select capacitors with an X7R dielectric.
Flying Capacitor (C1)
The value of the flying capacitor (C1) affects the load
regulation and output resistance of the charge pump. A
C1 value that is too small degrades the device’s ability
to provide sufficient current drive, which leads to a loss
of output voltage. Connect a 1µF capacitor between
C1P and C1N.
fRC
dB IN IN
−=
31
2π
INPUT COUPLING CAPACITOR-INDUCED THD+N
vs. FREQUENCY (HEADPHONE MODE)
FREQUENCY (Hz)
THD+N (dB FS)
100
-85
-80
-75
-70
-65
-60
-55
-50
-90
10 1000
0402 6.3V X5R 10% 1μF
0603 10V X5R 10% 1μF
0805 25V X7R 10% 1μF
1206 25 X7R 10% 1μFVOUT = -3dB FS
FS = 1VRMS
RL = 32Ω
Figure 7. Input Coupling Capacitor-Induced THD+N vs.
Frequency (Headphone Mode)
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
20 ______________________________________________________________________________________
Output Capacitor (C2)
The output capacitor value and ESR directly affect the
ripple at CPVSS. Increasing the value of C2 reduces
output ripple. Likewise, decreasing the ESR of C2
reduces both ripple and output resistance. Lower
capacitance values can be used in systems with low
maximum output power levels.
CPV
DD
Bypass Capacitor (C3)
The CPVDD bypass capacitor (C3) lowers the output
impedance of the power supply and reduces the
impact of the MAX9789/MAX9790’s charge-pump
switching transients. Bypass CPVDD with 1µF, the same
value as C1, and place it physically close to the CPVDD
and CPGND pins.
Layout and Grounding
Proper layout and grounding are essential for optimum
performance. Use large traces for the power-supply
inputs and amplifier outputs to minimize losses due to
parasitic trace resistance, as well as route heat away
from the device. Good grounding improves audio per-
formance, minimizes crosstalk between channels, and
prevents switching noise from coupling into the audio
signal. Connect PGND and GND together at a single
point on the PC board. Route PGND and all traces that
carry switching transients away from GND and the
traces and components in the audio signal path.
Connect C2 and C3 to the PGND plane. Connect PVSS
and CPVSS together at C2. Place the charge-pump
capacitors (C1, C2, and C3) as close as possible to
the device. Bypass PVDD with a 0.1µF capacitor to
PGND. Place the bypass capacitors as close as possi-
ble to the device.
Use large, low-resistance output traces. As load imped-
ance decreases, the current drawn from the device out-
puts increase. At higher current, the resistance of the
output traces decrease the power delivered to the load.
For example, if 2W is delivered from the speaker output
to a 4Ωload through a 100mΩtrace, 49mW is con-
sumed in the trace. If power is delivered through a
10mΩtrace, only 5mW is consumed in the trace. Large
output, supply and GND traces also improve the power
dissipation of the device.
The MAX9789/MAX9790 thin QFN package features an
exposed thermal pad on its underside. This pad lowers
the package’s thermal resistance by providing a direct
heat conduction path from the die to the printed circuit
board. Connect the exposed thermal pad to GND by
using a large pad and multiple vias to the GND plane.
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
______________________________________________________________________________________ 21
Block Diagrams
MAX9789
HP_EN 22
HP_INL 27
HP_INR 26
LDO_EN 4
VDD
30
LDO_SET 1
LDO_OUT 29
MUTE 25
SPKR_EN 23
GAIN2 32
GAIN1 31
STEREO
BTL
AMPLIFIER
CONTROL
CHARGE
PUMP
LDO BLOCK
TO HPVDD
TO PVSS
0.1µF
1.0µF
0.1µF
1.0µF
1.0µF
PVDD
8, 18
4.5V TO 5.5V
3
6 OUTL+
OUTL-
OUTR+
OUTR-
BIAS
HPL
HPR
HPVDD
CPVDD
C1P
C1N
CPGND
7
20
19
24
16
15
17
9
10
11
12
1314
PVSS
C2
1.0µF
CPVSS
5, 21
PGNDGND
28
SPKR_INL
SPKR_INR 2
1.0µF
1.0µF
1.0µF
1.0µF
1.0µF1.0µF
4.5V TO 5.5V
3V TO 5.5V
3V TO 5.5V
3V TO 5.5V
TO CODEC
LOGIC PINS CONFIGURED FOR:
LDO_EN = 1, LDO ENABLED
SPKR_EN = 0, SPEAKER AMPLIFIERS ENABLED
HP_EN = 1, HEADPHONE AMPLIFIER ENABLED
MUTE = 1, MUTE DISABLED
GAIN1 = 0 GAIN = 0, 6dB SPEAKER GAIN
C1
1µF
C3
10µF
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
22 ______________________________________________________________________________________
Block Diagrams (continued)
MAX9790
HP_EN 22
HP_INL 27
HP_INR 26
MUTE 25
SPKR_EN 23
GAIN2 32
GAIN1 31
STEREO
BTL
AMPLIFIER
CONTROL
CHARGE
PUMP
TO HPVDD
TO PVSS
0.1μF
0.1μF
1.0μF
1.0μF
1.0μF
VDD PVDD
30 8, 18
4.5V TO 5.5V
3
6 OUTL+
OUTL-
OUTR+
OUTR-
BIAS
HPL
HPR
HPVDD
CPVDD
C1P
C1N
CPGND
7
20
19
24
16
15
17
9
10
11
12
1314
PVSS
C2
1.0μF
CPVSS
5, 21
PGNDGND
4, 28
SPKR_INL
SPKR_INR 2
1.0μF
1.0μF
3V TO 5.5V
3V TO 5.5V
C1
1μF
C3
10μF
LOGIC PINS CONFIGURED FOR:
SPKR_EN = 0, SPEAKER AMPLIFIERS ENABLED
HP_EN = 1, HEADPHONE AMPLIFIER ENABLED
MUTE = 1, MUTE DISABLED
GAIN1 = 0 GAIN = 0, 6dB SPEAKER GAIN
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
______________________________________________________________________________________ 23
System Diagrams
MAX9789
MAX9713
10μF
0.1μF
CIN
1μF
VDD
BIAS PVDD
OUTL+
OUTL-
OUT+
OUT-
C1P
C1N
CHOLD
OUTR+
OUTR-
HPL
HPR
LDO_SET
GND PGND
SPKR_INL
CIN
1μFSPKR_INR
CIN
1μFHP_INR
CIN
1μFHP_INL
SPKR_L
SPKR_R
HP_R
HP_L
MONO
DGND AGND CPVDD
C1P
C1N
SPKR_EN
HP_EN
LDO_EN
GAIN1
GAIN2
MUTE
FS2
FS1
G1
G2
SHDN
IN+
5.0V
VLDO_OUT
5.0V
4.75V
12V
HPVDD
5.0V
PGND AGND
1μF 1μFCBULK
1μF
HDA
CODEC
μC
C3
1μFC1
1μF
C2
1μF
VDD
LDO_OUT
CPVSS
1μF
4Ω
4Ω
8Ω
1μF
PVSS
CPGND
VDD
100μF1μF
0.47μF
IN-
SS
0.47μF
0.47μFREG
0.01μF
1μF
0.1μF
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
24 ______________________________________________________________________________________
System Diagrams (continued)
MAX9789
MAX4411
10μF
1μF
1μF
VDD PVDD
OUTL+
OUTL-
C1P
C1N
PVSS
SVSS
OUTR+
OUTR-
HPL
HPR
GND PGND
SPKR_INL
1μF
SPKR_INR
1μF
HP_INR
1μF
HP_INL
SPKR_L
SPKR_R
HP1_R
HP1_L
HP2_R
HP2_L
AGNDDGND
CPVDD
C1P
C1N
SPKR_EN
LDO_EN
GAIN2
GAIN1
MUTE
SHDNR
INR
+5V
VLDO_OUT
+3.3V
HPVDD
+3.3V
SGND PGND
1μF 0.1μF
1μF 1μF
HDA
CODEC
μC
C3
1μFC1
1μF
C2
1μF
HP_EN
CPVSS
LDO_OUT
LDO_SET
PVSS
CPGND
4.75V
1μF
SHDNL
INL
PVDD
1μF
1μF
+3.3V
SVDD
1μF
1μF
OUTL HP2
HP1
OUTR
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
______________________________________________________________________________________ 25
Simplified Block Diagrams
(continued)
Chip Information
PROCESS: BiCMOS
Pin Configurations
MAX9789
TQFN
TOP VIEW
29
30
28
27
12
11
13
SPKR_INR
LDO_EN
PGND
OUTL+
OUTL-
14
LDO_SET
SPKR_EN
PGND
OUTR+
BIAS
OUTR-
PVDD
12
GND
4567
2324 22 20 19 18
LDO_OUT
VDD
PVSS
CPVSS
C1N
CPGND
SPKR_INL HP_EN
3
21
31 10
GAIN1 C1P
32
*EP = EXPOSED PADDLE
EP*
+
9
GAIN2 CPVDD
HP_INL
26 15 HPR
HP_INR
25 16 HPL
PVDD HPVDD
8
17
MUTE
MAX9790
29
30
28
27
12
11
13
SPKR_INR
GND
PGND
OUTL+
OUTL-
14
N.C.
SPKR_EN
PGND
OUTR+
BIAS
OUTR-
PVDD
12
GND
4567
2324 22 20 19 18
N.C.
VDD
PVSS
CPVSS
C1N
CPGND
SPKR_INL HP_EN
3
21
31 10
GAIN1 C1P
32 9
GAIN2 CPVDD
HP_INL
26 15 HPR
HP_INR
25 16 HPL
PVDD HPVDD
8
17
MUTE
TQFN
*EP = EXPOSED PADDLE
EP*
+
MAX9790
SPKR_EN
HP_EN
MUTE
GAIN1
GAIN2
SPEAKER SUPPLY
4.5V TO 5.5V
SPKR_INR
SPKR_INL
HP_INR
HP_INL
HEADPHONE SUPPLY
3.0V TO 5.5V
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
26 ______________________________________________________________________________________
QFN THIN.EPS
PACKAGE TYPE PACKAGE CODE DOCUMENT NO.
32 TQFN-EP T3255N-1 21-0140
Package Information
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the
package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the
package regardless of RoHS status.
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
______________________________________________________________________________________ 27
Package Information (continued)
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the
package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the
package regardless of RoHS status.
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
28
____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2009 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
2 8/08 Added MAX9789C to data sheet and made miscellaneous clarifications 1–11, 13, 14, 18
3 9/09 Corrected the Block Diagrams 21
