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 architecture, these ICs have symmetrical differential inputs
and a single-ended output. They operate from ±5V
supplies and are capable of driving a 100Ω load 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 maintaining up to a 5000V/µs slew rate. Excellent differential
gain/phase and noise specifications make these amplifiers ideal for a wide variety of video and RF signal-processing 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, A
VCL
≥ +2V/V)
♦ 550MHz -3dB Bandwidth
♦ -60dB SFDR at 5MHz
♦ Low Differential Gain/Phase: 0.07%/0.05°
♦ Low Noise: 25nV/√Hz at f
IN
= 100kHz
♦ Low-Power Disable Mode Reduces Quiescent
Current to 3.5mA
MAX4444/MAX4445
________________________________________________________________
Maxim Integrated Products
1
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
SIGNAL
INPUT
IN+
MAX4444
IN-
GND
+5V
0.1µF
EN
V
CC
OUT
V
EE
REF
0.1µF
-5V
75Ω
75Ω
OUTPUT
TOP VIEW
N.C. (RG)
N.C. (RG)
( ) ARE FOR MAX4445 ONLY.
V
CC
V
CC
IN-
IN+
V
EE
V
EE
1
2
3
MAX4444
4
MAX4445
5
6
7
8
SO
16
GND
15
OUT
14
V
EE
13
V
EE
12
V
EE
V
11
EE
10
REF
9
EN
MAX4444/MAX4445
Ultra-High-Speed, Low-Distortion, Differentialto-Single-Ended Line Receivers with Enable
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
DC ELECTRICAL CHARACTERISTICS
(V
CC
= +5V, VEE= -5V, VEN= ≥2V, VCM= 0 , RL= ∞, REF = GND, A
VCL
= +2V/V, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical
values are at T
A
= +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.
VCCto 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 ≤ V
OUT
≤ +3.5V, MAX4444
Guaranteed by CMRR test
-2.9V ≤ V
CM
≤ +2.9V
VS= ±4.5V to ±5.5V
RL= 30Ω
-3V ≤ V
OUT
≤ +3V
RL= 50Ω
RL= 100Ω
MAX4444
-2.9V ≤ V
IN
≤ +2.9V
RL= 100Ω
-3V ≤ V
OUT
≤ +3V,
R
L
= 100Ω
CONDITIONS
µA
2.2 10
I
IL
EN Logic Input Low Current
V
2
V
IH
EN Logic High Threshold
V
0.8
V
IL
EN Logic Low Threshold
kΩ
1.8
R
OUT(OFF)
Disable Output Resistance
dB
40 55
CMRRCommon-Mode Rejection Ratio
dB
53 70
PSRRPower-Supply Rejection Ratio
mA
90 120
I
OUT
Output Current Drive
MAX4445
±3.3 ±3.6
V
±3.4 ±3.7
V
OUT
Output Voltage Swing
%/°C
0.003
Gain-Error Drift
2.6 8
V
-1.7 1.7
V
DIFF
Differential Input Voltage Range
V
-2.9 2.9
V
CM
Input Common-Mode Voltage
Range
(1 + 600/RG)
2
A
V
Gain
170
kΩ
82
R
IN
Differential Input Resistance
mV
15 65
V
OS
Input Offset Voltage
µV/°C
12
TC
VOS
Input Offset-Voltage
Temperature Coefficient
µA
10 55
I
B
Input Bias Current
µA
0.25 45
I
OS
Input Offset Current
UNITSMIN TYP MAXSYMBOLPARAMETER
VIN= 0, VEN= 0
VIN= 0, VEN= 5V
VEN= 5V
3.5 5.5
mA
41 55
I
Q
Quiescent Current
µA
2.6 10
I
IH
EN Logic Input High Current
%
-2.9V ≤ V
CM
≤ +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, A
VCL
= +2V/V, TA= +25°C, unless otherwise noted.)
V
OUT
= 2Vp-p
Settle to 0.1% , V
OUT
= 2V step
V
OUT
= 1V step
V
OUT
= 2Vp-p
V
OUT
= 100mVp-p
V
OUT
= 2V step
CONDITION
-35
-55
dBc
-65
SFDR
ns12Settling Time
650
MHzBW
LS
Large-Signal -3dB Bandwidth
MHz550BW
SS
Small-Signal -3dB Bandwidth
ps
1200
500
MHz800.1dB Gain Flatness
5000
2400
UNITSMIN TYP MAXSYMBOLPARAMETER
-60
t
RISE
Rise Time (Note 1)
f = 100kHz
f = 100kHz (Note 2)
NTSC, RL= 150Ω
pA/√Hz
1.8i
N
Input Noise Current Density
nV/√Hz
25e
N
Input Noise Voltage Density
degrees0.05DPDifferential Phase Error
NTSC, RL= 150Ω %0.07DGDifferential Gain Error
V
OUT
= 100mVp-p
fC= 100kHz
fC= 100MHz
fC= 20MHz
fC= 5MHz
V
OUT
= 2Vp-p
fC= 100MHz -35
fC= 100kHz
fC= 20MHz
fC= 5MHz
-50
dBc
-65
2nd-Harmonic Distortion
-62
V
OUT
= 2Vp-p
fC= 100MHz -55
fC= 100kHz
fC= 20MHz
fC= 5MHz
-62
dBc
-90
3rd-Harmonic Distortion
-72
V
OUT
= 4V step
V
OUT
= 0.5V step
V
OUT
= 1V step
V
OUT
= 2V step
700
700
700
ps
825
t
FALL
Fall Time (Note 1)
V/µsSRSlew Rate (Note 1)
V
OUT
= 0.5V step 600
MAX4444
V
OUT
= 4V step
MAX4445
MAX4444
MAX4445
3800
2000
VIN= 1V, V
OUT
settle to within 10%
VIN= 1V, V
OUT
settle to within 10%
ns200t
SHDN(OFF)
Disable Time
ns80t
SHDN(ON)
Enable Time
f = 10MHz Ω0.7Z
OUT
Output Impedance
VIN= 1V, V
OUT
settle to within 10%
VIN= 1V, V
OUT
settle to within 10%
µs0.3t
OFF
Power-Down Time
µs0.5t
ON
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, Differentialto-Single-Ended Line Receivers with Enable
4 _______________________________________________________________________________________
Typical Operating Characteristics
(V
CC
= +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)
V
OUT
= 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)
V
OUT
= 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)
V
OUT
= 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)
V
OUT
= 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)
V
OUT
= 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)
V
OUT
= 2Vp-p
MAX4444/MAX4445
Ultra-High-Speed, Low-Distortion, Differential-
to-Single-Ended Line Receivers with Enable
_______________________________________________________________________________________
5
Typical Operating Characteristics (continued)
(V
CC
= +5V, VEE= -5V, VEN= 5V, VIN= VIN+ - VIN-, RL= 100Ω, REF = GND, AV= +2V/V, TA= +25°C, unless otherwise noted.)
LARGE-SIGNAL PULSE RESPONSE
INPUT
250mV/div
OUTPUT
500mV/div
0
-10
-20
-30
-40
-50
-60
DISTORTION (dB)
-70
-80
-90
-100
500k 1M
0
-10
-20
-30
-40
-50
-60
DISTORTION (dB)
-70
-80
-90
-100
100 1k 10k
MAX4445
5ns/div
MAX4444
HARMONIC DISTORTION
vs. FREQUENCY
V
OUT
2nd HARMONIC
3rd HARMONIC
10M 100M
FREQUENCY (Hz)
MAX4445
HARMONIC DISTORTION
vs. LOAD RESISTANCE
fC = 5MHz, V
OUT
2nd HARMONIC
3rd HARMONIC
LOAD RESISTANCE (Ω)
= 2Vp-p
= 2Vp-p
MAX4445toc10
SLEW RATE (V/µs)
MAX4444toc13
DISTORTION (dB)
MAX4444toc16
SLEW RATE vs. OUTPUT VOLTAGE SWING
6000
5000
4000
3000
2000
1000
0
0 1.00.5 1.5 2.0 2.5 3.0 3.5 4.0 4.5
OUTPUT VOLTAGE SWING (Vp-p)
MAX4444
MAX4445
MAX4445
HARMONIC DISTORTION
vs. FREQUENCY
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
0
2nd HARMONIC
3rd HARMONIC
500k 1M
FREQUENCY (Hz)
V
10M 100M
MAX4444
HARMONIC DISTORTION
vs. OUTPUT VOLTAGE SWING
0
-10
-20
-30
-40
-50
-60
DISTORTION (dB)
-70
-80
-90
-100
0.5 1.5 2.5 3.5 4.5 5.5 6.5
OUTPUT VOLTAGE SWING (Vp-p)
2nd HARMONIC
3rd HARMONIC
OUT
fC = 5MHz
= 2Vp-p
MAX4444/45toc11
GAIN (%)
PHASE (degrees)
MAX4445toc14
DISTORTION (dB)
MAX4444toc17
DIFFERENTIAL GAIN AND PHASE
0.08
0.06
0.04
0.02
0
-0.02
-0.04
-0.06
-0.08
0
0.01
0
-0.01
-0.02
-0.03
-0.04
-0.05
0
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
100 1k 10k
vs. OUTPUT VOLTAGE SWING
0
-10
-20
-30
-40
-50
-60
DISTORTION (dB)
-70
-80
-90
-100
0.5 1.5 2.5 3.5 4.5 5.5 6.5
OUTPUT VOLTAGE SWING (Vp-p)
MAX4444
IRE
IRE
MAX4444
HARMONIC DISTORTION
vs. LOAD RESISTANCE
fC = 5MHz, V
OUT
2nd HARMONIC
3rd HARMONIC
LOAD RESISTANCE (Ω)
MAX4445
HARMONIC DISTORTION
2nd HARMONIC
3rd HARMONIC
MAX4444toc12
100
100
= 2Vp-p
MAX4444toc15
fC = 5MHz
MAX4445toc18
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, Differentialto-Single-Ended Line Receivers with Enable
6 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(V
CC
= +5V, VEE= -5V, VEN= 5V, VIN= VIN+ - VIN-, RL= 100Ω, REF = GND, AV= +2V/V, TA= +25°C, unless otherwise noted.)
3.90
3.85
3.80
3.75
3.70
OUTPUT VOLTAGE (V)
3.65
VOLTAGE SWING
vs. LOAD RESISTANCE
MAX4445
MAX4444
MAX4444/45toc20
Hz)
VOLTAGE NOISE (nV/√
INPUT VOLTAGE NOISE DENSITY
1000
100
vs. FREQUENCY
MAX4444/45toc21
INPUT CURRENT NOISE DENSITY
100
10
CURRENT NOISE (pA/√Hz)
vs. FREQUENCY
MAX4444/45toc22
3.60
0 800400 1200 1600 2000
LOAD RESISTANCE (Ω)
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
0
-10
-20
-30
-40
PSRR (dB)
-50
-60
-70
-80
100k 10M 100M1M 1G
FREQUENCY (Hz)
SHUTDOWN RESPONSE
SHUTDOWN
PULSE
2.5V/div
OUTPUT
1V/div
10
1 100k10010
1k
FREQUENCY (Hz)
COMMON-MODE REJECTION
vs. FREQUENCY
0
-10
MAX4444/45toc23
-20
-30
-40
CMR (dB)
-50
-60
-70
-80
100k 10M 100M1M 1G
FREQUENCY (Hz)
MAX4444
RECOMMENDED ISOLATION
RESISTANCE vs. CAPACITIVE LOAD
24
22
MAX4444/45toc26
20
(Ω)
18
ISO
R
16
14
10k 1M 10M
1
1 10 100 1k 10k 100k 1M 10M
FREQUENCY (Hz)
CLOSED-LOOP OUTPUT IMPEDANCE
vs. FREQUENCY
1000
100
MAX4444/45toc24
10
(Ω)
OUT
Z
1
-0.1
-0.01
100k 10M 100M1M 1G
MAX4444toc27
FREQUENCY (Hz)
MAX4444
MAX4444toc25
200ns/div
12
81210 14 16 18 20 22 24
CAPACITIVE LOAD (pF)
MAX4444/MAX4445
Ultra-High-Speed, Low-Distortion, Differential-
to-Single-Ended Line Receivers with Enable
_______________________________________________________________________________________
7
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 performance.
9 9
Active-High Enable Input. Connect to V
CC
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
V
CC
IN-
N.C.
EN
V
EE
IN+
RG
GND
OUT
REF
Typical Operating Characteristics (continued)
(V
CC
= +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
12
10
8
6
4
INPUT BIAS CURRENT (µA)
2
INPUT BIAS CURRENT
vs. TEMPERATURE
5
MAX4444/45toc29
4
3
2
QUIESCENT CURRENT (mA)
1
QUIESCENT CURRENT
vs. TEMPERATURE
EN = GND
MAX4444/45toc31
0
-40 -10-25 5 2035506580
TEMPERATURE (°C)
0
-40 -15 10 35 60 85
TEMPERATURE (°C)
MAX4444/MAX4445
Ultra-High-Speed, Low-Distortion, Differentialto-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 performance, and are ideally suited for video and RF signal-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 capability allows them to be directly coupled to data acquisition 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 surface-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 R
GAIN
.
Setting Gain (MAX4445)
The MAX4445 is stable with a minimum gain configuration of +2V/V. R
GAIN
, 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 / R
GAIN
)
Driving Capacitive Loads
The MAX4444/MAX4445 are designed to drive capacitive 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 recommended 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 75Ω characteristic impedance of common
coaxial cables. Adjust the gain of the MAX4445 to compensate 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 V
EE
+
RG
R
GAIN
MAX4445
RG
GAIN = 1 +
600
R
GAIN
IN
MAX4444
MAX4445
IN–
R
ISO
C
LOAD
Loading...