General Description
The MAX1181 is a 3V, dual 10-bit, analog-to-digital
converter (ADC) featuring fully-differential wideband
track-and-hold (T/H) inputs, driving two pipelined, nine-
stage ADCs. The MAX1181 is optimized for low-power,
high-dynamic performance applications in imaging,
instrumentation, and digital communication applica-
tions. The MAX1181 operates from a single 2.7V to 3.6V
supply, consuming only 246mW, while delivering a typi-
cal signal-to-noise ratio (SNR) of 59dB at an input fre-
quency of 20MHz and a sampling rate of 80Msps. The
T/H driven input stages incorporate 400MHz (-3dB)
input amplifiers. The converters may also be operated
with single-ended inputs. In addition to low operating
power, the MAX1181 features a 2.8mA sleep mode, as
well as a 1µA power-down mode to conserve power
during idle periods.
An internal 2.048V precision bandgap reference sets
the full-scale range of the ADC. A flexible reference
structure allows the use of the internal or external
reference, if desired for applications requiring
increased accuracy or a different input voltage range.
The MAX1181 features parallel, CMOS-compatible
three-state outputs. The digital output format is set to
two’s complement or straight offset binary through a
single control pin. The device provides for a separate
output power supply of 1.7V to 3.6V for flexible interfac-
ing. The MAX1181 is available in a 7mm 7mm, 48-pin
TQFP package, and is specified for the extended
industrial (-40°C to +85°C) temperature range.
Pin-compatible higher and lower speed versions of the
MAX1181 are also available. Please refer to the
MAX1180 datasheet for 105Msps, the MAX1182
datasheet for 65Msps, the MAX1183 datasheet for
40Msps, and the MAX1184 datasheet for 20Msps. In
addition to these speed grades, this family includes a
20Msps multiplexed output version (MAX1185), for
which digital data is presented time-interleaved on a
single, parallel 10-bit output port.
Applications
High-Resolution Imaging
I/Q Channel Digitization
Multichannel IF Undersampling
Instrumentation
Video Application
Features
Single 3V Operation
Excellent Dynamic Performance
59dB SNR at fIN = 20MHz
73dB SFDR at fIN = 20MHz
Low Power
82mA (Normal Operation)
2.8mA (Sleep Mode)
1µA (Shutdown Mode)
0.02dB Gain and 0.25° Phase Matching (typ)
Wide ±1VP-P Differential Analog Input Voltage
Range
400MHz, -3dB Input Bandwidth
On-Chip 2.048V Precision Bandgap Reference
User-Selectable Output Format—Two’s
Complement or Offset Binary
48-Pin TQFP Package with Exposed Pad for
Improved Thermal Dissipation
Evaluation Kit Available
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
________________________________________________________________ Maxim Integrated Products 1
D1A
D0A
OGND
OVDD
OVDD
OGND
D0B
D1B
D2B
D3B
D4B
D5B
COM
VDD
GND
INA+
INA-
VDD
GND
INB-
INB+
GND
VDD
CLK
1
2
3
4
5
6
7
8
9
10
11
12
36
35
34
33
32
31
30
29
28
27
26
25
48 TQFP-EP
MAX1181
GND
VDD
GND
VDD
T/B
SLEEP
PD
OE
D9B
D8B
D7B
D6B
13
14
15
16
17
18
19
20
21
22
23
24
48
47
46
45
44
43
42
41
40
39
38
37
REFN
REFP
REFIN
REFOUT
D9A
D8A
D7A
D6A
D5A
D4A
D3A
D2A
EP*
NOTE: THE PIN 1 INDICATOR FOR LEAD-FREE PACKAGES IS REPLACED
BY A "+" SIGN.
Pin Configuration
Ordering Information
19-2093; Rev 1; 2/07
EVALUATION KIT
AVAILABLE
PART TEMP RANGE PIN-PACKAGE
MAX1181ECM -40°C to +85°C 48 TQFP-EP*
MAX1181ECM+
-40°C to +85°C 48 TQFP-EP*
Functional Diagram appears at end of data sheet.
*EP = Exposed paddle.
+Denotes a lead-free package.
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.
ELECTRICAL CHARACTERISTICS
(VDD = 3V, OVDD = 2.5V; 0.1µF and 1.0µF capacitors from REFP, REFN, and COM to GND; REFOUT connected to REFIN through a
10kΩresistor, VIN = 2VP-P (differential with respect to COM), CL= 10pF at digital outputs (Note 1), fCLK = 83.333MHz, TA= TMIN to
TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
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.
VDD, OVDD to GND ...............................................-0.3V to +3.6V
OGND to GND.......................................................-0.3V to +0.3V
INA+, INA-, INB+, INB- to GND ...............................-0.3V to VDD
REFIN, REFOUT, REFP, REFN, CLK,
COM to GND ...........................................-0.3V to (VDD + 0.3V)
OE, PD, SLEEP, T/B, D9A–D0A,
D9B–D0B to OGND ..............................-0.3V to (OVDD + 0.3V)
Continuous Power Dissipation (TA= +70°C)
48-Pin TQFP-EP (derate 30.4mW/°C above +70°C) ...2430mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-60°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
UNITS
DC ACCURACY
Resolution 10 Bits
Integral Nonlinearity INL fIN = 7.47MHz
±0.6 ±2.2
LSB
Differential Nonlinearity DNL
fIN = 7.47MHz, no missing codes guaranteed ±0.4 ±1.0
LSB
Offset Error -2 +2
% FS
Gain Error 0±2
% FS
ANALOG INPUT
Differential Input Voltage Range
VDIFF Differential or single-ended inputs
±1.0
V
Common-Mode Input Voltage
Range VCM VDD/2
± 0.5
V
Input Resistance RIN Switched capacitor load 25 kΩ
Input Capacitance CIN 5pF
CONVERSION RATE
Maximum Clock Frequency fCLK 80
MHz
Data Latency 5Clock
Cycles
DYNAMIC CHARACTERISTICS
fINA or B = 7.47MHz, TA = +25°C
56.5 59.5
fINA or B = 20MHz, TA = +25°C5659
Signal-to-Noise Ratio
(Note 3) SNR
fINA or B = 39.9MHz 59
dB
fINA or B = 7.47MHz, TA = +25°C5659
fINA or B = 20MHz, TA = +25°C
55.3 58.5
Signal-to-Noise And Distortion
(Note 3)
SINAD
fINA or B = 39.9MHz
58.5
dB
fINA or B = 7.47MHz, TA = +25°C6575
fINA or B = 20MHz, TA = +25°C6473
Spurious-Free Dynamic
Range (Note 3) SFDR
fINA or B = 39.9MHz 71
dBc
fINA or B = 7.47MHz -76
fINA or B = 20MHz -76
Third-Harmonic Distortion
(Note 3) HD3
fINA or B = 39.9MHz -75
dBc
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VDD = 3V, OVDD = 2.5V; 0.1µF and 1.0µF capacitors from REFP, REFN, and COM to GND; REFOUT connected to REFIN through a
10kΩresistor, VIN = 2VP-P (differential with respect to COM), CL= 10pF at digital outputs (Note 1), fCLK = 83.333MHz, TA= TMIN to
TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
UNITS
fINA or B = 7.47MHz, TA = +25°C
-73 -64
fINA or B = 20MHz, TA = +25°C
-70 -63
Total Harmonic Distortion
(First Four Harmonics) (Note 3) THD
fINA or B = 39.9MHz
-70
dBc
Intermodulation Distortion
(First Five Odd-Order IMDs) IMD
fINA or B = 38.1546MHz at -6.5dBFS
fINA or B = 41.9532MHz at -6.5dBFS
(Note 4)
-73.5
dBc
Small-Signal Bandwidth Input at -20dBFS, differential inputs
500
MHz
Full-Power Bandwidth FPBW Input at -0.5dBFS, differential inputs
400
MHz
Aperture Delay tAD 1ns
Aperture Jitter tAJ 2ps
RMS
Overdrive Recovery Time For 1.5 x full-scale input 2 ns
Differential Gain
±1
%
Differential Phase
±0.25
degrees
Output Noise INA+ = INA- = INB+ = INB- = COM
0.2
LSBRMS
INTERNAL REFERENCE
Reference Output Voltage
REFOUT 2.048
±3%
V
Reference Temperature
Coefficient
TCREF 60
ppm/°C
Load Regulation
1.25
mV/mA
BUFFERED EXTERNAL REFERENCE (VREFIN = 2.048V)
REFIN Input Voltage
VREFIN 2.048
V
Positive Reference Output
Voltage VREFP
2.012
V
Negative Reference Output
Voltage
VREFN 0.988
V
Differential Reference Output
Voltage Range
ΔVREF
ΔVREF = VREFP - VREFN
0.95 1.024 1.10
V
REFIN Resistance
RREFIN > 50
MΩ
Maximum REFP, COM Source
Current
ISOURCE > 5
mA
Maximum REFP, COM Sink
Current ISINK
250
µA
Maximum REFN Source Current
ISOURCE 250
µA
Maximum REFN Sink Current ISINK
> 5
mA
UNBUFFERED EXTERNAL REFERENCE (VREFIN = AGND, reference voltage applied to REFP, REFN and COM )
REFP, REFN Input Resistance
RREFP
RREFN
Measured between REFP and COM and
REFN and COM 4kΩ
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
4 _______________________________________________________________________________________
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
UNITS
Differential Reference Input
Voltage
ΔVREF
ΔVREF = VREFP - VREFN 1.024
± 10% V
COM Input Voltage VCOM VDD / 2
± 10% V
REFP Input Voltage VREFP VCOM
+ ΔVREF / 2 V
REFN Input Voltage
VREFN
VCOM
- ΔVREF / 2 V
DIGITAL INPUTS (CLK, PD, OE, SLEEP, T/B)
CLK 0.8 x
VDD
Input High Threshold VIH
PD, OE, SLEEP, T/B 0.8 x
OVDD
V
CLK 0.2 x
VDD
Input Low Threshold VIL
PD, OE, SLEEP, T/B 0.2 x
OVDD
V
Input Hysteresis VHYST 0.1 V
IIH VIH = OVDD or VDD (CLK) ±5
Input Leakage IIL VIL = 0 ±5µA
Input Capacitance CIN 5pF
DIGITAL OUTPUTS (D9A–D0A, D9B–D0B)
Output-Voltage Low VOL ISINK = 200µA 0.2 V
Output-Voltage High VOH ISOURCE = 200µA OVDD
- 0.2
V
Three-State Leakage Current ILEAK OE = OVDD
±10
µA
Three-State Output Capacitance
COUT OE = OVDD 5pF
POWER REQUIREMENTS
Analog Supply Voltage Range VDD 2.7 3.0 3.6 V
Output Supply Voltage Range OVDD 1.7 2.5 3.6 V
Operating, fINA or B = 20MHz at -0.5dBFS 82 97
Sleep mode 2.8 mA
Analog Supply Current IVDD
Shutdown, clock idle, PD = OE = OVDD 115µA
Operating, CL = 15pF , fINA or B = 20MHz at
-0.5dBFS 13 mA
Sleep mode 100
Output Supply Current IOVDD
Shutdown, clock idle, PD = OE = OVDD 210
µA
Operating, fINA or B = 20MHz at -0.5dBFS 246
291
mW
Sleep mode 8.4Power Dissipation
PDISS
Shutdown, clock idle, PD = OE = OVDD 345
µW
ELECTRICAL CHARACTERISTICS (continued)
(VDD = 3V, OVDD = 2.5V; 0.1µF and 1.0µF capacitors from REFP, REFN, and COM to GND; REFOUT connected to REFIN through a
10kΩresistor, VIN = 2VP-P (differential with respect to COM), CL= 10pF at digital outputs (Note 1), fCLK = 83.333MHz, TA= TMIN to
TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
_______________________________________________________________________________________ 5
-100
-80
-90
-60
-70
-40
-50
-30
-10
-20
0
010155 2025303540
FFT PLOT CHA (8192-POINT RECORD,
DIFFERENTIAL INPUT)
MAX1181 toc01
ANALOG INPUT FREQUENCY (MHz)
AMPLITUDE (dB)
fINA = 6.0449MHz
fINB = 7.5099MHz
fCLK = 80.0006MHz
AINA = -0.46dBFS
CHA
-100
-80
-90
-60
-70
-40
-50
-30
-10
-20
0
010155 2025303540
FFT PLOT CHB (8192-POINT RECORD,
DIFFERENTIAL INPUT)
MAX1181 toc02
ANALOG INPUT FREQUENCY (MHz)
AMPLITUDE (dB)
fINA = 6.0449MHz
fINB = 7.5099MHz
fCLK = 80.0006MHz
AINB = -0.52dBFS
CHB
-100
-80
-90
-60
-70
-40
-50
-30
-10
-20
0
010155 2025303540
FFT PLOT CHA (8192-POINT RECORD,
DIFFERENTIAL INPUT)
MAX1181 toc03
ANALOG INPUT FREQUENCY (MHz)
AMPLITUDE (dB)
fINA = 19.9123MHz
fINB = 24.9123MHz
fCLK = 80.0006MHz
AINA = -0.52dBFS
CHA
Typical Operating Characteristics
(VDD = 3V, OVDD = 2.5V, internal reference, differential input at -0.5dBFS, fCLK = 80.0006MHz, CL10pF. TA= +25°C, unless other-
wise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
UNITS
Offset
±0.2
mV/V
Power Supply Rejection PSRR Gain
±0.1
%/V
TIMING CHARACTERISTICS
CLK Rise to Output Data Valid tDO Figure 3 (Note 5) 5 8 ns
Output Enable Time
tENABLE
Figure 4
10
ns
Output Disable Time
tDISABLE
Figure 4
1.5
ns
CLK Pulse-Width High tCH Figure 3 clock period: 12ns
6 ±1
ns
CLK Pulse-Width Low tCL Figure 3 clock period: 12ns
6 ±1
ns
Wakeup from sleep mode
0.28
Wake-Up Time (Note 6) tWAKE Wakeup from shutdown
1.5
µs
CHANNEL-TO-CHANNEL MATCHING
Crosstalk fINA or B = 20MHz at -0.5dBFS
-70
dB
Gain Matching fINA or B = 20MHz at -0.5dBFS
0.02 ±0.2
dB
Phase Matching fINA or B = 20MHz at -0.5dBFS
0.25
degrees
ELECTRICAL CHARACTERISTICS (continued)
(VDD = 3V, OVDD = 2.5V; 0.1µF and 1.0µF capacitors from REFP, REFN, and COM to GND; REFOUT connected to REFIN through a
10kΩresistor, VIN = 2VP-P (differential with respect to COM), CL= 10pF at digital outputs (Note 1), fCLK = 83.333MHz, TA= TMIN to
TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)
Note 1: Equivalent dynamic performance is obtainable over full OVDD range with reduced CL.
Note 2: Specifications at +25°C are guaranteed by production test and < +25°C are guaranteed by design and characterization.
Note 3: SNR, SINAD, THD, SFDR, and HD3 are based on an analog input voltage of -0.5dBFS, referenced to a +1.024V full-scale
input voltage range.
Note 4: Intermodulation distortion is the total power of the intermodulation products relative to the individual carrier. This number is
6dB or better, if referenced to the two-tone envelope.
Note 5: Digital outputs settle to VIH, VIL. Parameter guaranteed by design.
Note 6: With REFIN driven externally, REFP, COM, and REFN are left floating while powered down.
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
6 _______________________________________________________________________________________
-100
-80
-90
-60
-70
-40
-50
-30
-10
-20
0
010155 2025303540
FFT PLOT CHB (8192-POINT RECORD,
DIFFERENTIAL INPUT)
MAX1181 toc04
ANALOG INPUT FREQUENCY (MHz)
AMPLITUDE (dB)
f
INA
= 19.9123MHz
f
INB
= 24.9123MHz
f
CLK
= 80.0006MHz
A
INB
= -0.53dBFS
CHB
-100
-80
-90
-60
-70
-40
-50
-30
-10
-20
0
010155 2025303540
FFT PLOT CHA (8192-POINT RECORD,
DIFFERENTIAL INPUT)
MAX1181 toc05
ANALOG INPUT FREQUENCY (MHz)
AMPLITUDE (dB)
fINA = 40.4202MHz
fINB = 47.0413MHz
fCLK = 80.0006MHz
AINA = -0.52dBFS
CHA
-100
-80
-90
-60
-70
-40
-50
-30
-10
-20
0
010155 2025303540
FFT PLOT CHB (8192-POINT RECORD,
DIFFERENTIAL INPUT)
MAX1181 toc06
ANALOG INPUT FREQUENCY (MHz)
AMPLITUDE (dB)
fINA = 40.4202MHz
fINB = 47.0413MHz
fCLK = 80.0006MHz
AINB = -0.53dBFS
CHB
-100
-80
-90
-60
-70
-40
-50
-30
-10
-20
0
010155 2025303540
TWO-TONE IMD PLOT (8192-POINT RECORD,
COHERENT SAMPLING)
MAX1181 toc07
ANALOG INPUT FREQUENCY (MHz)
AMPLITUDE (dB)
fIN1 = 38.1546MHz
fIN2 = 41.9632MHz
fCLK = 80.0006MHz
AIN1 = AIN2 = -6dBFS
2nd ORDER IMD
fIN1
fIN2
55
58
57
56
59
60
61
0403010 20 50 60 70 80 90 100
SIGNAL-TO-NOISE RATIO
vs. ANALOG INPUT FREQUENCY
MAX1181 toc08
ANALOG INPUT FREQUENCY (MHz)
SNR (dB)
CHA
CHB
55
58
57
56
59
60
61
0403010 20 50 60 70 80 90 100
SIGNAL-TO-NOISE AND DISTORTION
vs. ANALOG INPUT FREQUENCY
MAX1181 toc09
ANALOG INPUT FREQUENCY (MHz)
SINAD (dB)
CHA
CHB
-80
-77
-74
-71
-68
-65
0405020 3010 60 70 80 90 100
TOTAL HARMONIC DISTORTION
vs. ANALOG INPUT FREQUENCY
MAX1181 toc10
ANALOG INPUT FREQUENCY (MHz)
THD (dBc)
CHA
CHB
65
68
71
74
77
80
0405020 3010 60 70 80 90 100
SPURIOUS-FREE DYNAMIC RANGE
vs. ANALOG INPUT FREQUENCY
MAX1181 toc11
ANALOG INPUT FREQUENCY (MHz)
SFDR (dBc)
CHA
CHB
1 10 100 1000
FULL-POWER INPUT BANDWIDTH
vs. ANALOG INPUT FREQUENCY
(SINGLE-ENDED)
MAX1181 toc12
ANALOG INPUT FREQUENCY (MHz)
GAIN (dB)
6
-8
-6
-2
0
2
4
-4
Typical Operating Characteristics (continued)
(VDD = 3V, OVDD = 2.5V, internal reference, differential input at -0.5dBFS, fCLK = 80.0006MHz, CL10pF. TA= +25°C, unless other-
wise noted.)
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
_______________________________________________________________________________________ 7
1 10 100 1000
SMALL-SIGNAL INPUT BANDWIDTH
vs. ANALOG INPUT FREQUENCY
(SINGLE-ENDED)
MAX1181 toc13
ANALOG INPUT FREQUENCY (MHz)
GAIN (dB)
6
-8
-6
-2
0
2
4
-4
VIN = 100mVP-P
45
50
60
55
65
SIGNAL-TO-NOISE RATIO
vs. ANALOG INPUT POWER (fIN = 20MHz)
MAX1181 toc14
ANALOG INPUT POWER (dBFS)
SNR (dB)
-9 -6 -5-8 -7 -4 -3 -2 -1 0
SIGNAL-TO-NOISE AND DISTORTION
vs. ANALOG INPUT POWER (fIN = 20MHz)
MAX1181 toc15
ANALOG INPUT POWER (dBFS)
SINAD (dB)
-9 -6 -5-8 -7 -4 -3 -2 -1 0
50
52
56
54
58
60
-100
-85
-95
-90
-70
-80
-75
-60
-65
-55
-45
-50
-40
-9 -7 -6 -5-8 -4 -3 -2 -1 0
TOTAL HARMONIC DISTORTION vs. ANALOG
INPUT POWER (fIN = 20MHz)
MAX1181 toc16
ANALOG INPUT POWER (dBFS)
THD (dBc)
40
55
45
50
70
60
65
80
75
85
95
90
100
-9 -7 -6 -5-8 -4 -3 -2 -1 0
SPURIOUS-FREE DYNAMIC RANGE vs. ANALOG
INPUT POWER (fIN = 20MHz)
MAX1181 toc17
ANALOG INPUT POWER (dBFS)
SFDR (dBc)
-1.0
-0.6
-0.8
-0.2
-0.4
0.2
0
0.4
0.8
0.6
1.0
0 256 384128 512 640 768 896 1024
INTEGRAL NONLINEARITY
(BEST-STRAIGHT-LINE FIT)
MAX1181 toc18
DIGITAL OUTPUT CODE
INL (LSB)
-1.0
-0.6
-0.8
-0.2
-0.4
0.2
0
0.4
0.8
0.6
1.0
0 256 384128 512 640 768 896 1024
DIFFERENTIAL NONLINEARITY
MAX1181 toc19
DIGITAL OUTPUT CODE
DNL (LSB)
-2
0
-1
2
1
3
4
-40 10-15 35 60 85
GAIN ERROR vs. TEMPERATURE,
EXTERNAL REFERENCE (VREFIN = 2.048V)
MAX1181 toc20
TEMPERATURE (°C)
GAIN ERROR (LSB)
CHA
CHB
-5
-3
1
-1
3
5
-40 10-15 35 60 85
OFFSET ERROR vs. TEMPERATURE,
EXTERNAL REFERENCE (VREFIN = 2.048V)
MAX11811 toc21
TEMPERATURE (°C)
OFFSET ERROR (LSB)
CHA
CHB
Typical Operating Characteristics (continued)
(VDD = 3V, OVDD = 2.5V, internal reference, differential input at -0.5dBFS, fCLK = 80.0006MHz, CL10pF. TA= +25°C, unless other-
wise noted.)
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
8 _______________________________________________________________________________________
50
60
80
70
90
100
2.70 3.002.85 3.15 3.30 3.45 3.60
ANALOG SUPPLY CURRENT
vs. ANALOG SUPPLY VOLTAGE
MAX1181 toc22
VDD (V)
IVDD (mA)
50
60
80
70
90
100
-40 10-15 35 60 85
ANALOG SUPPLY CURRENT vs. TEMPERATURE
MAX11811 toc23
TEMPERATURE (°C)
IVDD (mA)
0
0.4
1.2
0.8
1.6
2.0
2.70 3.002.85 3.15 3.30 3.45 3.60
ANALOG POWER-DOWN CURRENT
vs. ANALOG POWER SUPPLY
MAX1181 toc24
VDD (V)
IVDD (μA)
OE = PD = OVDD
50
60
55
70
65
75
80
35 45 5040 55 60 65
SNR/SINAD, -THD/SFDR
vs. CLOCK DUTY CYCLE
MAX1181 toc25
CLOCK DUTY CYCLE (%)
SNR/SINAD, -THD/SFDR (dB, dBc)
SFDR
fINA = 24.9123MHz
-THD
SINAD
SNR
2.025
2.035
2.055
2.045
2.065
2.075
2.70 3.002.85 3.15 3.30 3.45 3.60
INTERNAL REFERENCE VOLTAGE
vs. ANALOG SUPPLY VOLTAGE
MAX1181 toc26
VDD (V)
VREFOUT (V)
2.00
2.02
2.06
2.04
2.08
2.10
-40 10-15 35 60 85
INTERNAL REFERENCE VOLTAGE
vs. TEMPERATURE
MAX11811 toc27
TEMPERATURE (°C)
VREFOUT (V)
0
40000
20000
80000
60000
120000
100000
140000
N - 1N - 2
0965 730 0
129377
NN + 1 N + 2
OUTPUT NOISE HISTOGRAM (DC INPUT)
MAX1181 toc28
DIGITAL OUTPUT NOISE
COUNTS
Typical Operating Characteristics (continued)
(VDD = 3V, OVDD = 2.5V, internal reference, differential input at -0.5dBFS, fCLK = 80.0006MHz, CL10pF. TA= +25°C, unless other-
wise noted.)
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
_______________________________________________________________________________________ 9
Pin Description
PIN NAME FUNCTION
1 COM Common-Mode Voltage Input/Output. Bypass to GND with a 0.1µF capacitor.
2, 6, 11, 14, 15
VDD
Analog Supply Voltage. Bypass each supply pin to GND with a 0.1µF capacitor. The analog
supply voltage accepts a 2.7V to 3.6V input range.
3, 7, 10, 13, 16
GND Analog Ground
4 INA+ Channel ‘A’ Positive Analog Input. For single-ended operation, connect signal source to INA+.
5 INA- Channel ‘A’ Negative Analog Input. For single-ended operation, connect INA- to COM.
8 INB- Channel ‘B’ Negative Analog Input. For single-ended operation, connect INB- to COM.
9 INB+ Channel ‘B’ Positive Analog Input. For single-ended operation, connect signal source to INB+.
12 CLK Converter Clock Input
17 T/B
T/B selects the ADC digital output format.
High: Two’s complement.
Low: Straight offset binary.
18 SLEEP
Sleep Mode Input.
High: Deactivates the two ADCs, but leaves the reference bias circuit active.
Low: Normal operation.
19 PD
Power-Down Input.
High: Power-down mode.
Low: Normal operation.
20 OE
Output Enable Input.
High: Digital outputs disabled.
Low: Digital outputs enabled.
21 D9B Three-State Digital Output, Bit 9 (MSB), Channel B
22 D8B Three-State Digital Output, Bit 8, Channel B
23 D7B Three-State Digital Output, Bit 7, Channel B
24 D6B Three-State Digital Output, Bit 6, Channel B
25 D5B Three-State Digital Output, Bit 5, Channel B
26 D4B Three-State Digital Output, Bit 4, Channel B
27 D3B Three-State Digital Output, Bit 3, Channel B
28 D2B Three-State Digital Output, Bit 2, Channel B
29 D1B Three-State Digital Output, Bit 1, Channel B
30 D0B Three-State Digital Output, Bit 0 (LSB), Channel B
31, 34 OGND Output Driver Ground
32, 33 OVDD
Output Driver Supply Voltage. Bypass each supply pin to OGND with a 0.1µF capacitor. The
digital supply voltage accepts a 1.7V to 3.6V input range.
35 D0A Three-State Digital Output, Bit 0 (LSB), Channel A
36 D1A Three-State Digital Output, Bit 1, Channel A
37 D2A Three-State Digital Output, Bit 2, Channel A
38 D3A Three-State Digital Output, Bit 3, Channel A
39 D4A Three-State Digital Output, Bit 4, Channel A
MAX1181
Detailed Description
The MAX1181 uses a nine-stage, fully-differential
pipelined architecture (Figure 1), that allows for high-
speed conversion while minimizing power consump-
tion. Samples taken at the inputs move progressively
through the pipeline stages every half clock cycle.
Counting the delay through the output latch, the clock-
cycle latency is five clock cycles.
1.5-bit (two-comparator) flash ADCs convert the held-
input voltages into a digital code. The digital-to-analog
converters (DACs) convert the digitized results back
into analog voltages, which are then subtracted from
the original held-input signals. The resulting error sig-
nals are then multiplied by two, and the residues are
passed along to the next pipeline stages where the
process is repeated until the signals have been
processed by all nine stages. Digital error correction
compensates for ADC comparator offsets in each of
these pipeline stages and ensures no missing codes.
Input Track-and-Hold (T/H) Circuits
Figure 2 displays a simplified functional diagram of the
input track-and-hold (T/H) circuits in both track-and-
hold mode. In track mode, switches S1, S2a, S2b, S4a,
S4b, S5a and S5b are closed. The fully-differential cir-
cuits sample the input signals onto the two capacitors
(C2a and C2b) through switches S4a and S4b. S2a and
S2b set the common mode for the amplifier input, and
open simultaneously with S1, sampling the input wave-
form. Switches S4a and S4b are then opened before
switches S3a and S3b connect capacitors C1a and
C1b to the output of the amplifier and switch S4c is
closed. The resulting differential voltages are held on
capacitors C2a and C2b. The amplifiers are used to
charge capacitors C1a and C1b to the same values
originally held on C2a and C2b. These values are then
presented to the first-stage quantizers and isolate the
pipelines from the fast-changing inputs. The wide input
bandwidth T/H amplifiers allow the MAX1181 to track
and sample/hold analog inputs of high frequencies
(> Nyquist). Both ADC inputs (INA+, INB+, INA-, and
INB-) can be driven either differentially or single-ended.
Match the impedance of INA+ and INA-, as well as
INB+ and INB-, and set the common-mode voltage to
midsupply (VDD / 2) for optimum performance.
Analog Inputs and Reference
Configurations
The full-scale range of the MAX1181 is determined by
the internally generated voltage difference between
REFP (VDD / 2 + VREFIN / 4) and REFN (VDD / 2 -
VREFIN / 4). The full-scale range for both on-chip ADCs is
adjustable through the REFIN pin, which is provided for
this purpose.
REFOUT, REFP, COM (VDD / 2) and REFN are internally
buffered low-impedance outputs.
The MAX1181 provides three modes of reference
operation:
• Internal reference mode
• Buffered external reference mode
• Unbuffered external reference mode
In the internal reference mode, connect the internal ref-
erence output REFOUT to REFIN through a resistor
(e.g., 10kΩ) or resistor divider, if an application
requires a reduced full-scale range.
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
10 ______________________________________________________________________________________
Pin Description (continued)
PIN NAME FUNCTION
40 D5A Three-State Digital Output, Bit 5, Channel A
41 D6A Three-State Digital Output, Bit 6, Channel A
42 D7A Three-State Digital Output, Bit 7, Channel A
43 D8A Three-State Digital Output, Bit 8, Channel A
44 D9A Three-State Digital Output, Bit 9 (MSB), Channel A
45
REFOUT
Internal Reference Voltage Output. May be connected to REFIN through a resistor or a resistor
divider.
46 REFIN Reference Input. VREFIN = 2 x (VREFP - VREFN). Bypass to GND with a > 1nF capacitor.
47 REFP Positive Reference Input/Output. Conversion range is ±(VREFP - VREFN). Bypass to GND
with a > 0.1µF capacitor.
48 REFN Negative Reference Input/Output. Conversion range is ±(VREFP - VREFN). Bypass to GND
with a > 0.1µF capacitor.
EP Exposed Paddle. Connect to analog ground.
For stability and noise filtering purposes, bypass REFIN
with a > 10nF capacitor to GND. In internal reference
mode, REFOUT, COM, REFP, and REFN become low-
impedance outputs.
In the buffered external reference mode, adjust the ref-
erence voltage levels externally by applying a stable
and accurate voltage at REFIN. In this mode, COM,
REFP, and REFN become outputs. REFOUT may be left
open or connected to REFIN through a > 10kΩresistor.
In the unbuffered external reference mode, connect
REFIN to GND. This deactivates the on-chip reference
buffers for REFP, COM, and REFN. With their buffers
shut down, these nodes become high impedance and
may be driven through separate external reference
sources.
Clock Input (CLK)
The MAX1181’s CLK input accepts CMOS-compatible
clock signals. Since the interstage conversion of the
device depends on the repeatability of the rising and
falling edges of the external clock, use a clock with low
jitter and fast rise and fall times (< 2ns). In particular,
sampling occurs on the rising edge of the clock signal,
requiring this edge to provide lowest possible jitter. Any
significant aperture jitter would limit the SNR perfor-
mance of the on-chip ADCs as follows:
SNR = 20 log10 (1 / [2πx fIN tAJ]),
where fIN represents the analog input frequency and
tAJ is the time of the aperture jitter.
Clock jitter is especially critical for undersampling
applications. The clock input should always be consid-
ered as an analog input and routed away from any ana-
log input or other digital signal lines.
The MAX1181 clock input operates with a voltage thresh-
old set to VDD / 2. Clock inputs with a duty cycle other
than 50% must meet the specifications for high and low
periods as stated in the Electrical Characteristics table.
System Timing Requirements
Figure 3 depicts the relationship between the clock
input, analog input, and data output. The MAX1181
samples at the rising edge of the input clock. Output
data for channels A and B is valid on the next rising
edge of the input clock. The output data has an internal
latency of five clock cycles. Figure 4 also determines
the relationship between the input clock parameters
and the valid output data on channels A and B.
Digital Output Data, Output Data Format
Selection (T/B), Output Enable (
OE
)
All digital outputs, D0A–D9A (Channel A) and D0B–D9B
(Channel B), are TTL/CMOS logic-compatible. There is a
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
______________________________________________________________________________________ 11
T/H VOUT
x2
Σ
FLASH
ADC DAC
1.5 BITS
10
VINA
VIN
STAGE 1 STAGE 2
D9A–D0A
VINA = INPUT VOLTAGE BETWEEN INA+ AND INA- (DIFFERENTIAL OR SINGLE-ENDED)
VINB = INPUT VOLTAGE BETWEEN INB+ AND INB- (DIFFERENTIAL OR SINGLE-ENDED)
DIGITAL CORRECTION LOGIC
STAGE 8 STAGE 9
2-BIT FLASH
ADC
T/H
T/H VOUT
x2
Σ
FLASH
ADC DAC
1.5 BITS
10
VINB
VIN
STAGE 1 STAGE 2
D9B–D0B
DIGITAL CORRECTION LOGIC
STAGE 8 STAGE 9
2-BIT FLASH
ADC
T/H
Figure 1. Pipelined Architecture––Stage Blocks
MAX1181
five clock cycle latency between any particular sample
and its corresponding output data. The output coding
can be chosen to be either straight offset binary or two’s
complement (Table 1) controlled by a single pin (T/B).
Pull T/B low to select offset binary and high to activate
two’s complement output coding. The capacitive load
on the digital outputs D0A–D9A and D0B–D9B should
be kept as low as possible (< 15pF), to avoid large digi-
tal currents that could feed back into the analog portion
of the MAX1181, thereby degrading its dynamic perfor-
mance. Using buffers on the digital outputs of the ADCs
can further isolate the digital outputs from heavy capaci-
tive loads. To further improve the dynamic performance
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
12 ______________________________________________________________________________________
S3b
S3a
COM
S5b
S5a
INB+
INB-
S1
OUT
OUT
C2a
C2b
S4c
S4a
S4b
C1b
C1a
INTERNAL
BIAS
INTERNAL
BIAS
COM
HOLD HOLD CLK
INTERNAL
NONOVERLAPPING
CLOCK SIGNALS
TRACK TRACK
S2a
S2b
S3b
S3a
COM
S5b
S5a
INA+
INA-
S1
OUT
OUT
C2a
C2b
S4c
S4a
S4b
C1b
C1a
INTERNAL
BIAS
INTERNAL
BIAS
COM
S2a
S2b
MAX1181
Figure 2. MAX1181 T/H Amplifiers
______________________________________________________________________________________________________ 13
of the MAX1181 small-series resistors (e.g., 100Ω), add
to the digital output paths, close to the MAX1181.
Figure 4 displays the timing relationship between out-
put enable and data output valid, as well as power-
down/wake-up and data output valid.
Power-Down (PD) and Sleep
(SLEEP) Modes
The MAX1181 offers two power-save modes; sleep and
full power-down mode. In sleep mode (SLEEP = 1),
only the reference bias circuit is active (both ADCs are
disabled) and current consumption is reduced to
2.8mA.
To enter full power-down mode, pull PD high. With OE
simultaneously low, all outputs are latched at the last
value prior to the power-down. Pulling OE high, forces
the digital outputs into a high-impedance state.
Applications Information
Figure 5 depicts a typical application circuit containing
two single-ended to differential converters. The internal
reference provides a VDD / 2 output voltage for level-
shifting purposes. The input is buffered and then split
to a voltage follower and inverter. One lowpass filter per
ADC suppresses some of the wideband noise associat-
ed with high-speed operational amplifiers. The user
may select the RISO and CIN values to optimize the fil-
ter performance to suit a particular application. For the
application in Figure 5, a RISO of 50Ωis placed before
the capacitive load to prevent ringing and oscillation.
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
DIFFERENTIAL INPUT
VOLTAGE* DIFFERENTIAL INPUT
STRAIGHT OFFSET
BINARY
T/B = 0
TWO’S COMPLEMENT
T/B = 1
VREF 511/512 +FULL SCALE - 1LSB 11 1111 1111 01 1111 1111
VREF 1/512 + 1 LSB 10 0000 0001 00 0000 0001
0 Bipolar Zero 10 0000 0000 00 0000 0000
-VREF 1/512 - 1 LSB 01 1111 1111 11 1111 1111
-VREF 511/512 - FULL SCALE + 1 LSB 00 0000 0001 10 0000 0001
-VREF 512/512 - FULL SCALE 00 0000 0000 10 0000 0000
Table 1. MAX1181 Output Codes For Differential Inputs
N - 6
N
N - 5
N + 1
N - 4
N + 2
N - 3
N + 3
N - 2
N + 4
N - 1
N + 5
N
N + 6
N + 1
5 CLOCK-CYCLE LATENCY
ANALOG INPUT
CLOCK INPUT
DATA OUTPUT
D9A–D0A
tD0 tCH tCL
N - 6 N - 5 N - 4 N - 3 N - 2 N - 1 N N + 1
DATA OUTPUT
D9B–D0B
tCLK
Figure 3. System Timing Diagram
*VREF = VREFP - VREFN
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
14 ______________________________________________________________________________________
The 22pF CIN capacitor acts as a small bypassing
capacitor.
Using Transformer Coupling
An RF transformer (Figure 6) provides an excellent
solution to convert a single-ended source signal to a
fully-differential signal, required by the MAX1181 for
optimum performance. Connecting the center tap of the
transformer to COM provides a VDD / 2 DC level shift to
the input. Although a 1:1 transformer is shown, a step-
up transformer may be selected to reduce the drive
requirements. A reduced signal swing from the input
driver, such as an op amp, may also improve the over-
all distortion.
In general, the MAX1181 provides better SFDR and
THD with fully-differential input signals, than a single-
ended drive, especially for high input frequencies. In
differential input mode, even-order harmonics are lower
as both inputs (INA+, INA- and/or INB+, INB-) are bal-
anced, and each of the ADC inputs only require half the
signal swing compared to single-ended mode.
Single-Ended AC-Coupled Input Signal
Figure 7 shows an AC-coupled, single-ended applica-
tion. Amplifiers, like the MAX4108, provide high-speed,
high bandwidth, low-noise, and low distortion to main-
tain the integrity of the input signal.
Typical QAM Demodulation Application
The most frequently used modulation technique for digi-
tal communications application is the Quadrature
Amplitude Modulation (QAM). QAMs are typically found
in spread-spectrum based systems. A QAM signal rep-
resents a carrier frequency modulated in both amplitude
and phase. At the transmitter, modulating the baseband
signal with quadrature outputs, a local oscillator fol-
lowed by subsequent up-conversion can generate the
QAM signal. The result is an in-phase (I) and a quadra-
ture (Q) carrier component, where the Q component is
90 degrees phase-shifted with respect to the in-phase
component. At the receiver, the QAM signal is divided
down into its I and Q components, essentially represent-
ing the modulation process reversed. Figure 8 displays
the demodulation process performed in the analog
domain, using the dual-matched, 3V, 10-bit ADCs,
MAX1181 and the MAX2451 quadrature demodulators,
to recover and digitize the I and Q baseband signals.
Before being digitized by the MAX1181, the mixed-down
signal components may be filtered by matched analog
filters, such as Nyquist or pulse-shaping filters which
remove any unwanted images from the mixing process,
enhances the overall signal-to-noise (SNR) perfor-
mance, and minimizes intersymbol interference.
Grounding, Bypassing,
and Board Layout
The MAX1181 requires high-speed board layout design
techniques. Locate all bypass capacitors as close to
the device as possible, preferably on the same side as
the ADC, using surface-mount devices for minimum
inductance. Bypass VDD, REFP, REFN, and COM with
two parallel 0.1µF ceramic capacitors and a 2.2µF
bipolar capacitor to GND. Follow the same rules to
bypass the digital supply (OVDD) to OGND. Multilayer
boards with separate ground and power planes, pro-
duce the highest level of signal integrity. Consider the
use of a split ground plane arranged to match the phys-
ical location of the analog ground (GND) and the digital
output driver ground (OGND) on the ADCs package.
The two ground planes should be joined at a single
point, such that the noisy digital ground currents do not
interfere with the analog ground plane. The ideal loca-
tion of this connection can be determined experimental-
ly at a point along the gap between the two ground
planes, which produces optimum results. Make this
connection with a low-value, surface-mount resistor (1Ω
to 5Ω), a ferrite bead, or a direct short. Alternatively, all
ground pins could share the same ground plane, if the
ground plane is sufficiently isolated from any noisy, dig-
ital systems ground plane (e.g., downstream output
buffer or DSP ground plane). Route high-speed digital
signal traces away from the sensitive analog traces of
either channel. Make sure to isolate the analog input
lines to each respective converter to minimize channel-
to-channel crosstalk. Keep all signal lines short and
free of 90 degree turns.
OUTPUT
D9A–D0A
OE
tDISABLE
tENABLE
HIGH IMPEDANCEHIGH IMPEDANCE VALID DATA
OUTPUT
D9B–D0B
HIGH IMPEDANCEHIGH IMPEDANCE VALID DATA
Figure 4. Output Timing Diagram
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
______________________________________________________________________________________ 15
INPUT
300Ω
-5V
+5V
0.1μF
0.1μF
0.1μF
-5V
600Ω
300Ω
300Ω
INA+
INA-
LOWPASS FILTER
COM
600Ω
+5V
-5V
0.1μF
600Ω
300Ω
600Ω
300Ω
0.1μF
0.1μF
0.1μF
+5V
0.1μF
300Ω
MAX4108
MAX1181
INB+
INB-
MAX4108
MAX4108
LOWPASS FILTER
INPUT
300Ω
-5V
+5V
0.1μF
0.1μF
0.1μF
CIN
22pF
-5V
600Ω
300Ω
300Ω
LOWPASS FILTER
600Ω
+5V
-5V
0.1μF
600Ω
300Ω
600Ω
300Ω
0.1μF
0.1μF
0.1μF
+5V
0.1μF
300Ω
MAX4108
MAX4108
MAX4108
LOWPASS FILTER
RISO
50ΩCIN
22pF
RISO
50ΩCIN
22pF
RISO
50ΩCIN
22pF
RISO
50Ω
Figure 5. Typical Application for Single-Ended-to-Differential Conversion
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
16 ______________________________________________________________________________________
Static Parameter Definitions
Integral Nonlinearity (INL)
Integral nonlinearity is the deviation of the values on an
actual transfer function from a straight line. This straight
line can be either a best straight-line fit or a line drawn
between the endpoints of the transfer function, once
offset and gain errors have been nullified. The static lin-
earity parameters for the MAX1181 are measured using
the best straight-line fit method.
Differential Nonlinearity (DNL)
Differential nonlinearity is the difference between an
actual step-width and the ideal value of 1LSB. A DNL
error specification of less than 1LSB guarantees no
missing codes and a monotonic transfer function.
Dynamic Parameter Definitions
Aperture Jitter
Figure 9 depicts the aperture jitter (tAJ), which is the
sample-to-sample variation in the aperture delay.
Aperture Delay
Aperture delay (tAD) is the time defined between the
falling edge of the sampling clock and the instant when
an actual sample is taken (Figure 9).
Signal-to-Noise Ratio (SNR)
For a waveform perfectly reconstructed from digital
samples, the theoretical maximum SNR is the ratio of
the full-scale analog input (RMS value) to the RMS
quantization error (residual error).
The ideal, theoretical minimum analog-to-digital noise is
caused by quantization error only and results directly
from the ADC’s resolution (N-Bits):
SNR[max] = 6.02 N + 1.76
In reality, there are other noise sources besides quanti-
zation noise; thermal noise, reference noise, clock jitter,
etc. SNR is computed by taking the ratio of the RMS
signal to the RMS noise, which includes all spectral
components minus the fundamental, the first five har-
monics, and the DC offset.
Signal-to-Noise Plus Distortion (SINAD)
SINAD is computed by taking the ratio of the RMS sig-
nal to all spectral components minus the fundamental
and the DC offset.
Effective Number of Bits (ENOB)
ENOB specifies the dynamic performance of an ADC at
a specific input frequency and sampling rate. An ideal
ADC’s error consists of quantization noise only. ENOB
is computed from:
Total Harmonic Distortion (THD)
THD is typically the ratio of the RMS sum of the first four
harmonics of the input signal to the fundamental itself.
This is expressed as:
THD VVVV
V
+++
20 10
2222
1
2345
log
ENOB SINAD
=176
602
.
.
MAX1181
T1
N.C.
VIN 6
1
5
2
43
22pF
22pF
0.1μF
0.1μF
2.2μF
25Ω
25Ω
MINI-CIRCUITS
TT1–6
T1
N.C.
VIN 6
1
5
2
43
22pF
22pF
0.1μF
0.1μF
2.2μF
25Ω
25Ω
MINI-CIRCUITS
TT1–6
INA-
INA+
INB-
INB+
COM
Figure 6. Transformer-Coupled Input Drive
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
______________________________________________________________________________________ 17
MAX1181
0.1μF
1kΩ
1kΩ
100Ω
100Ω
CIN
22pF
CIN
22pF
INB+
INB-
COM
INA+
INA-
0.1μFRISO
50Ω
RISO
50Ω
REFP
REFN
VIN
MAX4108
0.1μF
1kΩ
1kΩ
100Ω
100Ω
CIN
22pF
CIN
22pF
0.1μFRISO
50Ω
RISO
50Ω
REFP
REFN
VIN
MAX4108
Figure 7. Using an Op Amp for Single-Ended, AC-Coupled Input Drive
0°
90°
÷8
DOWNCONVERTER
MAX2451 INA+
MAX1181
INA-
INB+
INB-
DSP POST
PROCESSING
Figure 8. Typical QAM Application, Using the MAX1181
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
18 ______________________________________________________________________________________
GND
REFERENCE
OUTPUT
DRIVERS
CONTROL
T/H
T/H PIPELINE
ADC DEC OUTPUT
DRIVERS
REFOUT
REFN COM REFP REFIN
INA+
INA-
CLK
INB+
INB-
VDD
DEC
PIPELINE
ADC
OGND
OVDD
D9A–D0A
OE
D9B–D0B
T/B
PD
SLEEP
MAX1181
10
10 10
10
Functional Diagram
where V1is the fundamental amplitude, and V2through
V5are the amplitudes of the 2nd- through 5th-order
harmonics.
Spurious-Free Dynamic Range (SFDR)
SFDR is the ratio expressed in decibels of the RMS
amplitude of the fundamental (maximum signal compo-
nent) to the RMS value of the next largest spurious
component, excluding DC offset.
Intermodulation Distortion (IMD)
The two-tone IMD is the ratio expressed in decibels of
either input tone to the worst 3rd-order (or higher) inter-
modulation products. The individual input tone levels
are at -6.5dB full scale.
HOLD
ANALOG
INPUT
SAMPLED
DATA (T/H)
T/H
tAD
tAJ
TRACK TRACK
CLK
Figure 9. T/H Aperture Timing
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
______________________________________________________________________________________ 19
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
48L,TQFP.EPS
G
12
21-0065
PACKAGE OUTLINE,
48L TQFP, 7x7x1.0mm EP OPTION
MAX1181
Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs
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.
20 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.
G22
21-0065
PACKAGE OUTLINE,
48L TQFP, 7x7x1.0mm EP OPTION
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
Revision History
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