Ultra-High-Speed, Low-Distortion, Differential-
to-Single-Ended Line Receivers with Enable
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
General Description
The MAX4444/MAX4445 differential line receivers offer
unparalleled high-speed, low-distortion performance.
Using a three op amp instrumentation amplifier archi-
tecture, these ICs have symmetrical differential inputs
and a single-ended output. They operate from ±5V
supplies and are capable of driving a 100Ωload to
±3.7V. The MAX4444 has an internally set closed-loop
gain of +2V/V, while the MAX4445 is compensated for
gains of +2V/V or greater, set by an external resistor. A
low-power enable mode reduces current consumption
to 3.5mA.
Using current-feedback techniques, the MAX4444/
MAX4445 achieve a 550MHz bandwidth while maintain-
ing up to a 5000V/µs slew rate. Excellent differential
gain/phase and noise specifications make these ampli-
fiers ideal for a wide variety of video and RF signal-pro-
cessing applications. An evaluation kit is available to
speed design.
Applications
Differential-to-Single-Ended Conversion
Twisted-Pair to Coaxial Converter
High-Speed Instrumentation Amplifier
Data Acquisition
Medical Instrumentation
High-Speed Differential Line Receiver
Features
♦5000V/µs Slew Rate (MAX4444)
♦+2V/V Internally Fixed Gain (MAX4444)
♦External Gain Selection
(MAX4445, AVCL ≥+2V/V)
♦550MHz -3dB Bandwidth
♦-60dB SFDR at 5MHz
♦Low Differential Gain/Phase: 0.07%/0.05°
♦Low Noise: 25nV/√Hz at fIN = 100kHz
♦Low-Power Disable Mode Reduces Quiescent
Current to 3.5mA
MAX4444/MAX4445
________________________________________________________________
Maxim Integrated Products
1
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
VCC GND
OUT
VEE
VEE
VEE
VEE
REF
EN
TOP VIEW
MAX4444
MAX4445
SO
VCC
IN-
IN+
N.C. (RG)
N.C. (RG)
VEE
VEE
( ) ARE FOR MAX4445 ONLY.
75Ω
75Ω
0.1µF
GND
IN-
IN+
SIGNAL
INPUT OUTPUT
REF
EN
VEE
VCC
+5V
-5V
OUT
MAX4444
0.1µF
Typical Operating Circuit
19-1543; Rev 0; 10/99
EVALUATION KIT AVAILABLE
Pin Configuration
Ordering Information
PART
MAX4444ESE
MAX4445ESE -40°C to +85°C
-40°C to +85°C
TEMP. RANGE PIN-PACKAGE
16 Narrow SO
16 Narrow SO
MAX4444/MAX4445
Ultra-High-Speed, Low-Distortion, Differential-
to-Single-Ended Line Receivers with Enable
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
DC ELECTRICAL CHARACTERISTICS
(VCC = +5V, VEE = -5V, VEN = ≥2V, VCM = 0 , RL= ∞, REF = GND, AVCL = +2V/V, TA= TMIN to TMAX, unless otherwise noted. Typical
values are at TA= +25°C.)
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.
VCC to VEE ...........................................................................+12V
Voltage on IN+, IN-, EN, OUT+,
OUT-, RG, REF..............................(VEE - 0.3V) to (VCC + 0.3V)
Current Into IN+, IN-, RG, EN .............................................20mA
Output Short-Circuit Duration...........................Indefinite to GND
Continuous Power Dissipation (TA= +70°C)
16-Pin Narrow SO (derate 20mW/°C above +70°C)...1600mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10sec).............................+300°C
VEN = 0
Guaranteed by output swing test
VEN = 0, -3.5V ≤VOUT ≤+3.5V, MAX4444
Guaranteed by CMRR test
-2.9V ≤VCM ≤+2.9V
VS= ±4.5V to ±5.5V
RL= 30Ω
-3V ≤VOUT ≤+3V
RL= 50Ω
RL= 100Ω
MAX4444
-2.9V ≤VIN ≤+2.9V
RL= 100Ω
-3V ≤VOUT ≤+3V,
RL= 100Ω
CONDITIONS
µA
2.2 10
IIL
EN Logic Input Low Current V
2
VIH
EN Logic High Threshold V
0.8
VIL
EN Logic Low Threshold kΩ
1.8
ROUT(OFF)
Disable Output Resistance dB
40 55
CMRRCommon-Mode Rejection Ratio dB
53 70
PSRRPower-Supply Rejection Ratio mA
90 120
IOUT
Output Current Drive
MAX4445
±3.3 ±3.6 V
±3.4 ±3.7
VOUT
Output Voltage Swing
%/°C
0.003
Gain-Error Drift 2.6 8
V
-1.7 1.7
VDIFF
Differential Input Voltage Range
V
-2.9 2.9
VCM
Input Common-Mode Voltage
Range
(1 + 600/RG)
2
AV
Gain
170 kΩ
82
RIN
Differential Input Resistance
mV
15 65
VOS
Input Offset Voltage
µV/°C
12
TCVOS
Input Offset-Voltage
Temperature Coefficient
µA
10 55
IB
Input Bias Current
µA
0.25 45
IOS
Input Offset Current
UNITSMIN TYP MAXSYMBOLPARAMETER
VIN = 0, VEN = 0
VIN = 0, VEN = 5V
VEN = 5V
3.5 5.5 mA
41 55
IQ
Quiescent Current
µA
2.6 10
IIH
EN Logic Input High Current
%
-2.9V ≤VCM ≤+2.9V
V/V
Guaranteed by PSRR test V
±4.5 ±5.5
Operating Supply Voltage
Range
0.5 2
Gain Error MAX4445
MAX4444
V/µs
MAX4444/MAX4445
Ultra-High Speed, Low-Distortion, Differential-
to-Single-Ended Line Receivers with Enable
_______________________________________________________________________________________ 3
AC ELECTRICAL CHARACTERISTICS
(VCC = +5V, VEE = -5V, VEN = 5V, RL= 100Ω, REF = GND, AVCL = +2V/V, TA= +25°C, unless otherwise noted.)
VOUT = 2Vp-p
Settle to 0.1% , VOUT = 2V step
VOUT = 1V step
VOUT = 2Vp-p
VOUT = 100mVp-p
VOUT = 2V step
CONDITION
-35
-55 dBc
-65
SFDR
ns12Settling Time
650
MHzBWLS
Large-Signal -3dB Bandwidth MHz550BWSS
Small-Signal -3dB Bandwidth
ps
1200
500 MHz800.1dB Gain Flatness 5000
2400
UNITSMIN TYP MAXSYMBOLPARAMETER
-60
tRISE
Rise Time (Note 1)
f = 100kHz
f = 100kHz (Note 2)
NTSC, RL= 150Ω
pA/√Hz
1.8iN
Input Noise Current Density nV/√Hz
25eN
Input Noise Voltage Density
degrees0.05DPDifferential Phase Error NTSC, RL= 150Ω%0.07DGDifferential Gain Error
VOUT = 100mVp-p
fC= 100kHz
fC= 100MHz
fC= 20MHz
fC= 5MHz
VOUT = 2Vp-p
fC= 100MHz -35
fC= 100kHz
fC= 20MHz
fC= 5MHz -50 dBc
-65
2nd-Harmonic Distortion -62
VOUT = 2Vp-p
fC= 100MHz -55
fC= 100kHz
fC= 20MHz
fC= 5MHz -62 dBc
-90
3rd-Harmonic Distortion -72
VOUT = 4V step
VOUT = 0.5V step
VOUT = 1V step
VOUT = 2V step
700
700
700 ps
825
tFALL
Fall Time (Note 1)
V/µsSRSlew Rate (Note 1)
VOUT = 0.5V step 600
MAX4444
VOUT = 4V step MAX4445
MAX4444
MAX4445
3800
2000
VIN = 1V, VOUT settle to within 10%
VIN = 1V, VOUT settle to within 10% ns200tSHDN(OFF)
Disable Time ns80tSHDN(ON)
Enable Time f = 10MHz Ω0.7ZOUT
Output Impedance
VIN = 1V, VOUT settle to within 10%
VIN = 1V, VOUT settle to within 10% µs0.3tOFF
Power-Down Time µs0.5tON
Power-Up Time
Note 1: Input step voltage has <100ps rise (fall) time. Measured at the output from 10% to 90% (90% to 10%) level.
Note 2: Includes the current noise contribution through the on-die feedback resistor.
INPUT
25mV/div
OUTPUT
50mV/div
5ns/div
MAX4444
SMALL-SIGNAL PULSE RESPONSE
MAX4444toc07
INPUT
25mV/div
OUTPUT
50mV/div
5ns/div
MAX4445
SMALL-SIGNAL PULSE RESPONSE
MAX4445toc08
INPUT
250mV/div
OUTPUT
500mV/div
5ns/div
MAX4444
LARGE-SIGNAL PULSE RESPONSE
MAX4444toc09
MAX4444/MAX4445
Ultra-High-Speed, Low-Distortion, Differential-
to-Single-Ended Line Receivers with Enable
4 _______________________________________________________________________________________
Typical Operating Characteristics
(VCC = +5V, VEE = -5V, VEN = 5V, VIN = VIN+ - VIN-, RL= 100Ω, REF = GND, AV= +2V/V, TA= +25°C, unless otherwise noted.)
100M 1G
-5
-4
-3
-2
-1
0
1
3
2
4
5
100k 1M 10M
MAX4444
SMALL-SIGNAL GAIN vs. FREQUENCY
MAX4444toc01
FREQUENCY (Hz)
GAIN (dB)
VOUT = 100mVp-p
100M 1G
-6
-5
-4
-3
-2
-1
0
2
1
3
4
100k 1M 10M
MAX4445
SMALL-SIGNAL GAIN vs. FREQUENCY
MAX4444toc02
FREQUENCY (Hz)
GAIN (dB)
VOUT = 100mVp-p
100M 1G
-0.1
0
0.1
0.2
0.3
0.4
0.5
0.7
0.6
0.8
0.9
100k 1M 10M
MAX4444
GAIN FLATNESS vs. FREQUENCY
MAX4444toc03
FREQUENCY (Hz)
GAIN (dB)
VOUT = 100mVp-p
100M 1G
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.4
0.3
0.5
0.6
100k 1M 10M
MAX4445
GAIN FLATNESS vs. FREQUENCY
MAX4445toc04
FREQUENCY (Hz)
GAIN (dB)
VOUT = 100mVp-p
100M 1G
-5
-4
-3
-2
-1
0
1
3
2
4
5
100k 1M 10M
MAX4444
LARGE-SIGNAL GAIN vs. FREQUENCY
MAX4444toc05
FREQUENCY (Hz)
GAIN (dB)
VOUT = 2Vp-p
100M 1G
-6
-5
-4
-3
-2
-1
0
2
1
3
4
100k 1M 10M
MAX4445
LARGE-SIGNAL GAIN vs. FREQUENCY
MAX4445toc06
FREQUENCY (Hz)
GAIN (dB)
VOUT = 2Vp-p
MAX4444/MAX4445
Ultra-High-Speed, Low-Distortion, Differential-
to-Single-Ended Line Receivers with Enable
_______________________________________________________________________________________
5
INPUT
250mV/div
OUTPUT
500mV/div
5ns/div
MAX4445
LARGE-SIGNAL PULSE RESPONSE
MAX4445toc10
0
1000
2000
3000
4000
5000
6000
0 1.00.5 1.5 2.0 2.5 3.0 3.5 4.0 4.5
SLEW RATE vs. OUTPUT VOLTAGE SWING
MAX4444/45toc11
OUTPUT VOLTAGE SWING (Vp-p)
SLEW RATE (V/µs)
MAX4444
MAX4445
0.08
0.06
0.04
0.02
0
-0.02
-0.04
-0.06
-0.08
0100
100
MAX4444
DIFFERENTIAL GAIN AND PHASE
IRE
IRE
PHASE (degrees) GAIN (%)
0.01
0
-0.01
-0.02
-0.03
-0.04
-0.05
MAX4444toc12
0
0
-10
-20
-30
-100 10M 100M
MAX4444
HARMONIC DISTORTION
vs. FREQUENCY
-40
-50
-60
-70
-80
-90
MAX4444toc13
FREQUENCY (Hz)
DISTORTION (dB)
500k 1M
VOUT = 2Vp-p
2nd HARMONIC
3rd HARMONIC
0
-10
-20
-30
-100 10M 100M
MAX4445
HARMONIC DISTORTION
vs. FREQUENCY
-40
-50
-60
-70
-80
-90
MAX4445toc14
FREQUENCY (Hz)
DISTORTION (dB)
500k 1M
VOUT = 2Vp-p
2nd HARMONIC
3rd HARMONIC
0
-100 100 1k 10k
MAX4444
HARMONIC DISTORTION
vs. LOAD RESISTANCE
-80
-90
MAX4444toc15
LOAD RESISTANCE (Ω)
DISTORTION (dB)
-60
-70
-40
-30
-50
-20
-10 fC = 5MHz, VOUT = 2Vp-p
2nd HARMONIC
3rd HARMONIC
0
-100 100 1k 10k
MAX4445
HARMONIC DISTORTION
vs. LOAD RESISTANCE
-80
-90
MAX4444toc16
LOAD RESISTANCE (Ω)
DISTORTION (dB)
-60
-70
-40
-30
-50
-20
-10 fC = 5MHz, VOUT = 2Vp-p
2nd HARMONIC
3rd HARMONIC
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100 0.5 1.5 2.5 3.5 4.5 5.5 6.5
MAX4444
HARMONIC DISTORTION
vs. OUTPUT VOLTAGE SWING
MAX4444toc17
OUTPUT VOLTAGE SWING (Vp-p)
DISTORTION (dB)
fC = 5MHz
2nd HARMONIC
3rd HARMONIC
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100 0.5 1.5 2.5 3.5 4.5 5.5 6.5
MAX4445
HARMONIC DISTORTION
vs. OUTPUT VOLTAGE SWING
MAX4445toc18
OUTPUT VOLTAGE SWING (Vp-p)
DISTORTION (dB)
fC = 5MHz
2nd HARMONIC
3rd HARMONIC
Typical Operating Characteristics (continued)
(VCC = +5V, VEE = -5V, VEN = 5V, VIN = VIN+ - VIN-, RL= 100Ω, REF = GND, AV= +2V/V, TA= +25°C, unless otherwise noted.)
0
-5
-10
-15
-20 -40 10-15 35 60 85
INPUT OFFSET VOLTAGE
vs. TEMPERATURE
MAX4444/45toc28
TEMPERATURE (°C)
INPUT OFFSET VOLTAGE (mV)
MAX4444/MAX4445
Ultra-High-Speed, Low-Distortion, Differential-
to-Single-Ended Line Receivers with Enable
6 _______________________________________________________________________________________
3.90
3.85
3.80
3.75
3.70
3.65
3.60 0 800400 1200 1600 2000
VOLTAGE SWING
vs. LOAD RESISTANCE
MAX4444/45toc20
LOAD RESISTANCE (Ω)
OUTPUT VOLTAGE (V)
MAX4444
MAX4445
1 100k10010 1k 10k 1M 10M
INPUT VOLTAGE NOISE DENSITY
vs. FREQUENCY
MAX4444/45toc21
FREQUENCY (Hz)
VOLTAGE NOISE (nV/√
Hz)
10
100
1000
1 10 100 1k 10k 100k 1M 10M
INPUT CURRENT NOISE DENSITY
vs. FREQUENCY
MAX4444/45toc22
FREQUENCY (Hz)
CURRENT NOISE (pA/√Hz)
1
10
100
0
-10
-20
-30
-40
-50
-60
-70
-80 100k 10M 100M1M 1G
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
MAX4444/45toc23
FREQUENCY (Hz)
PSRR (dB)
0
-10
-20
-30
-40
-50
-60
-70
-80 100k 10M 100M1M 1G
COMMON-MODE REJECTION
vs. FREQUENCY
MAX4444/45toc24
FREQUENCY (Hz)
CMR (dB)
1000
100
10
1
-0.1
-0.01 100k 10M 100M1M 1G
MAX4444
CLOSED-LOOP OUTPUT IMPEDANCE
vs. FREQUENCY
MAX4444toc25
FREQUENCY (Hz)
ZOUT (Ω)
SHUTDOWN
PULSE
2.5V/div
OUTPUT
1V/div
200ns/div
SHUTDOWN RESPONSE
MAX4444/45toc26
12
14
16
18
20
22
24
81210 14 16 18 20 22 24
MAX4444
RECOMMENDED ISOLATION
RESISTANCE vs. CAPACITIVE LOAD
MAX4444toc27
CAPACITIVE LOAD (pF)
RISO (Ω)
Typical Operating Characteristics (continued)
(VCC = +5V, VEE = -5V, VEN = 5V, VIN = VIN+ - VIN-, RL= 100Ω, REF = GND, AV= +2V/V, TA= +25°C, unless otherwise noted.)
MAX4444/MAX4445
Ultra-High-Speed, Low-Distortion, Differential-
to-Single-Ended Line Receivers with Enable
_______________________________________________________________________________________
7
0
2
4
6
8
10
12
-40 -10-25 5 2035506580
INPUT BIAS CURRENT
vs. TEMPERATURE
MAX4444/45toc29
TEMPERATURE (°C)
INPUT BIAS CURRENT (µA)
0
1
3
2
4
5
-40 -15 10 35 60 85
QUIESCENT CURRENT
vs. TEMPERATURE
MAX4444/45toc31
TEMPERATURE (°C)
QUIESCENT CURRENT (mA)
EN = GND
Pin Description
PIN FUNCTION
MAX4444 MAX4445
1, 2 1, 2 Positive Power-Supply Input. Bypass with a 0.1µF capacitor to GND.
3 3 Inverting Amplifier Input
4, 5 — No Connection. Not internally connected. Connect to GND for best AC perfor-
mance.
9 9 Active-High Enable Input. Connect to VCC for normal operation. Connect to GND
for disable mode.
7, 8, 11–14 7, 8, 11–14 Negative Supply Input. Bypass with a 0.1µF capacitor.
6 6 Noninverting Amplifier Input
— 4, 5 Resistor Gain Input. Connect a resistor between these pins to set closed-loop
gain (Figure 1).
16 16 Ground
15 15 Amplifier Output
10 10 Reference Input. Connect to midpoint of the two power supplies.
NAME
VCC
IN-
N.C.
EN
VEE
IN+
RG
GND
OUT
REF
Typical Operating Characteristics (continued)
(VCC = +5V, VEE = -5V, VEN = 5V, VIN = VIN+ - VIN-, RL= 100Ω, REF = GND, AV= +2V/V, TA= +25°C, unless otherwise noted.)
35
38
37
36
39
40
41
42
43
44
45
-40 10-15 35 60 85
QUIESCENT CURRENT
vs. TEMPERATURE
MAX4444/45toc30
TEMPERATURE (°C)
QUIESCENT CURRENT (mA)
EN = 5V
MAX4444/MAX4445
Ultra-High-Speed, Low-Distortion, Differential-
to-Single-Ended Line Receivers with Enable
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.
8
_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 1999 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
_______________Detailed Description
The MAX4444/MAX4445 differential-to-single-ended
line receivers offer high-speed and low-distortion per-
formance, and are ideally suited for video and RF sig-
nal-processing applications. These receivers offer a
small-signal bandwidth of 550MHz and have a high
slew rate of up to 5000V/µs. Their 120mA output capa-
bility allows them to be directly coupled to data acquisi-
tion systems.
__________Applications Information
Grounding Bypassing
Use the following high-frequency design techniques
when designing the PC board for the MAX4444/
MAX4445.
• Use a multilayer board with one layer dedicated as
the ground plane.
• Do not use wire wrap or breadboards due to high
inductance.
• Avoid IC sockets due to high parasitic capacitance
and inductance.
• Bypass supplies with a 0.1µF capacitor. Use sur-
face-mount capacitors to minimize lead inductance.
• Keep signal lines as short and straight as possible.
Do not make 90° turns. Use rounded corners. Do not
cross signal paths if possible.
• Ensure that the ground plane is free from voids.
Low-Power Enable Mode
The MAX4444/MAX4445 are disabled when EN goes
low. This reduces supply current to only 3.5mA. As the
output becomes higher impedance, the effective
impedance at the output for the MAX4444 is 1.8kΩ. The
effective output impedance for the MAX4445 is 1.8kΩ
plus RGAIN.
Setting Gain (MAX4445)
The MAX4445 is stable with a minimum gain configura-
tion of +2V/V. RGAIN, connected between the RG pins,
sets the gain of this device as shown in Figure 1.
Calculate the expected gain as follows:
Gain = (1 + 600 / RGAIN)
Driving Capacitive Loads
The MAX4444/MAX4445 are designed to drive capaci-
tive loads. However, excessive capacitive loads may
cause ringing or instability at the output as the phase
margin of the device reduces. Adding a small series
isolation resistor at the output helps reduce the ringing
but slightly increases gain error (Figure 2). For recom-
mended values, see
Typical Operating Characteristics
.
Coaxial Line Driver
The MAX4444/MAX4445 are well suited to drive coaxial
cables. Their high output current capability can easily
drive the 75Ωcharacteristic impedance of common
coaxial cables. Adjust the gain of the MAX4445 to com-
pensate for cable losses to maintain the required levels
at the input of the next stage.
Figure 1. Setting the Amplifier Gain Figure 2. Using an Isolation Resistor for High Capacitive Loads
Chip Information
TRANSISTOR COUNT: 254
SUBSTRATE CONNECTED TO VEE
RGAIN
GAIN = 1 + 600
RGAIN
RG
RG
MAX4445
RISO
CLOAD
MAX4444
MAX4445
IN+
IN–
