MAXIM MAX442ESA

19-0016; Rev 1; 1/95
140MHz, 2-Channel
Video Multiplexer/Amplifier
________________________Applications
Broadcast-Quality Video-Signal Multiplexing
Coaxial-Cable Drivers
____________________________Features
♦ 140MHz Unity-Gain Bandwidth
♦ 250V/µs Slew Rate
♦ 0.07%/0.09° Differential Gain/Phase Error
♦ 36ns Channel Switch Time
♦ No External Compensation Components
♦ 8-Pin DIP and SO Packages
♦ Directly Drives 50Ω and 75Ω Cables
______________Ordering Information
PART
TEMP. RANGE
PIN-PACKAGE
MAX442CPA
0°C to +70°C
8 Plastic DIP
MAX442CSA
MAX442C/D
MAX442EPA
MAX442ESA
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
8 SO
Dice*
8 Plastic DIP
8 SO
*Dice are specified at TA = +25°C, DC parameters only.
Video Editing
Video Security Systems
__________Typical Operating Circuit
Medical Imaging
High-Speed Signal Processing
+5V
0.1µF
__________________Pin Configuration
V+
TOP VIEW
MAX442
VOUT
IN0 1
8
A0
GND 2
7
V+
6
VOUT
5
IN-
IN1 3
MAX442
V- 4
VIDEO
SIGNALS
IN
75Ω
75Ω
CABLE
VIDEO
OUTPUT
IN0
270Ω
IN1
75Ω
IN-
A0
GND
V-
270Ω
0.1µF
DIP/SO
CHANNEL
SELECT
-5V
________________________________________________________________ Maxim Integrated Products
Call toll free 1-800-998-8800 for free samples or literature.
1
MAX442
_______________General Description
The MAX442 combines a 140MHz video amplifier with a
high-speed, 2-channel multiplexer in an 8-pin package.
With its 36ns switching time and low differential gain
(0.07%) and phase (0.09°) errors, it is ideal for broadcast-quality video applications. The device is designed
to drive both 50Ω and 75Ω cables, and can directly
drive a 75Ω load to ±3V.
The MAX442 video amplifier is compensated for unitygain stability, and features a 140MHz bandwidth and a
250V/µs slew rate. The multiplexer’s low input capacitance (4pF with the channel on or off) maximizes highspeed performance, and a ground pin separating the
two input channels minimizes crosstalk and simplifies
board layout.
The MAX442 operates from ±5V supplies and typically
consumes 300mW. For applications that require more
input channels, see the data sheets for the MAX440 8channel mux/amp and the MAX441 4-channel mux/amp.
MAX442
140MHz, 2-Channel
Video Multiplexer/Amplifier
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V+ to V-).......................................................12V
Analog Input Voltage ............................(V+ + 0.3V) to (V- - 0.3V)
Digital Input Voltage .....................................-0.3V to (V+ + 0.3V)
Short-Circuit Current Duration ........................................1 minute
Input Current to Any Pin, Power On or Off........................±50mA
Continuous Power Dissipation (TA = +70°C)
Plastic DIP (derate 9.09mW/°C above +70°C) ............727mW
SO (derate 5.88mW/°C above +70°C) .........................471mW
Operating Temperature Ranges
MAX442C_A........................................................0°C to +70°C
MAX442E_A .....................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10sec) .............................+300°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.
ELECTRICAL CHARACTERISTICS
(V+ = 5V, V- = -5V, RL = 150Ω, TA = TMIN to TMAX, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
V
±1.5
±7.0
DC PERFORMANCE
Input Voltage Range
Input Offset Voltage
(All Channels)
VIN
VOS
Input Leakage Current
(Channel Off)
MAX442C
±10
MAX442E
±12
TA = +25°C
Offset Matching
(VOS0–VOS1)
Input Bias Current
(Channel On)
-2
TA = +25°C
±1
TA = TMIN to TMAX
IB
VIN = 0V
ILKG
VIN = 0V
±5.0
TA = +25°C
±0.6
TA = TMIN to TMAX
TA = +25°C
±0.5
TA = TMIN to TMAX
TA = +25°C
0.5
TA = TMIN to TMAX
0.2
2.0
RIN
-2V ≤ VCM ≤ 2V
Input Capacitance
CIN
Channel on or off
4
AV = 0dB
25
AV = 6dB
50
ROUT
Open-Loop Voltage Gain
AVOL
RL = 75Ω,
-2V ≤ VOUT ≤ +2V
Common-Mode Rejection Ratio
CMRR
-2V ≤ VIN ≤ +2V
Power-Supply Rejection Ratio
PSRR
±4.75V to ±5.25V
Output Voltage Swing
VOUT
RL = 75Ω
2
±2
±5
Input Resistance
(Channel On) (Note 1)
DC Output Resistance
±2.5
TA = +25°C
50
TA = TMIN to TMAX
46
TA = +25°C
46
TA = TMIN to TMAX
46
TA = +25°C
54
TA = TMIN to TMAX
54
TA = +25°C
±2.5
TA = TMIN to TMAX
±2.0
60
50
80
±3.0
_______________________________________________________________________________________
mV
mV
µA
±50
nA
±1
µA
MΩ
pF
mΩ
dB
dB
dB
V
140MHz, 2-Channel
Video Multiplexer/Amplifier
(V+ = 5V, V- = -5V, RL = 150Ω, TA = TMIN to TMAX, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DYNAMIC PERFORMANCE
-3dB Bandwidth
BW
Slew Rate
SR1
Differential Phase Error
DP
Differential Gain Error
DG
Settling Time
ts
Crosstalk
XTALK
Input Noise-Voltage Density
en
AV = 0dB, RL = 100Ω
140
MHz
250
V/µs
Figure 1
0.09
degrees
Figure 1
0.07
%
To 0.1% of final value,
AV = 0dB, RL = 150Ω, 2V step input
50
ns
f = 10MHz, RS = 75Ω, AV = 0dB, Figure 6
76
dB
f = 10kHz
12
nV/√Hz
POWER REQUIREMENTS
Operating Supply-Voltage Range
VS
Positive Supply Current
±4.75
ICC
Negative Supply Current
IEE
VIN = 0V
VIN = 0V
±5.25
TA = +25°C
25
30
MAX442C
22
38
MAX442E
19
41
TA = +25°C
23
MAX442C
20
38
MAX442E
17
41
V
35
28
mA
35
mA
SWITCHING CHARACTERISTICS
Logic Low Voltage
VIL
Logic High Voltage
VIH
0.8
V
Address Propagation Delay
tAPD
Figure 7
24
ns
Channel Switching Time
tSW
Figure 7 (Note 2)
36
ns
2.4
V
Note 1: Incremental resistance for a common-mode voltage between ±2V.
Note 2: Channel Switching Time specified between two grounded input channels; does not include signal rise/fall times for switching between channels with different input voltages.
__________________________________________Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
20
50
40
0
-45
PHASE
15
10
5
30
-90
20
-135
10
-180
0
-225
-10
-10
-270
-15
-315
1000
-20
-20
0.001
0.1
10
FREQUENCY (MHz)
AVCL = 20dB
AVCL = 6dB
AVCL = 0dB
0
-5
0.1
1
10
100
FREQUENCY (MHz)
1000
MAX442-03
45
GAIN
100
OUTPUT IMPEDANCE (Ω)
25
MAX442-02
30
90
CLOSED-LOOP GAIN (dB)
135
70
PHASE SHIFT (Degrees)
OPEN-LOOP GAIN (dB)
80
60
UNITY-GAIN OUTPUT IMPEDANCE
vs. FREQUENCY
CLOSED-LOOP GAIN
vs. FREQUENCY
OPEN-LOOP GAIN AND PHASE
vs. FREQUENCY
10
1
0.1
0.01
10k
100k
1M
10M
100M
FREQUENCY (Hz)
_______________________________________________________________________________________
3
MAX442
ELECTRICAL CHARACTERISTICS (continued)
____________________________Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
VOLTAGE-NOISE DENSITY
vs. FREQUENCY
10
3
OUTPUT VOLTAGE (V)
100
MAX442-06
4
-20
-40
-60
-80
2
1
0
-1
-2
-3
-100
-4
-5
-120
10
100
1k
10k
100k
1
10
1000
100
100
1k
FREQUENCY (Hz)
FREQUENCY (MHz)
LOAD RESISTANCE (Ω)
SUPPLY CURRENT
vs. TEMPERATURE
INPUT OFFSET VOLTAGE
vs. TEMPERATURE
INPUT BIAS CURRENT
vs. TEMPERATURE
10
0
-10
IEE
3
2
1
0
-1
-2
-3
-30
-4
-40
-5
0
20
40
60
80
MAX442-09
0.9
VCM = 0V
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
-40 -20
100
10k
1.0
INPUT BIAS CURRENT (µA)
20
-20
4
INPUT OFFSET VOLTAGE (mV)
ICC
30
5
MAX442-07
40
-40 -20
10
MAX442-08
1
0
20
40
60
80
100
-40 -20
0
20
40
60
80
100
TEMPERATURE (°C)
TEMPERATURE (°C)
OPEN-LOOP VOLTAGE GAIN
vs. TEMPERATURE
COMMON-MODE REJECTION RATIO
vs. TEMPERATURE
DIFFERENTIAL INPUT OFFSET VOLTAGE
vs. TEMPERATURE
60
50
40
30
20
10
0
80
70
60
50
40
30
20
10
0
-40 -20
0
20
40
60
TEMPERATURE (°C)
80
100
-40 -20
0
20
40
60
TEMPERATURE (°C)
80
100
3
MAX442-12
70
MAX442-11
MAX442-10
80
DIFFERENTIAL INPUT OFFSET VOLTAGE (mV)
TEMPERATURE (°C)
COMMON-MODE REJECTION RATIO (dB)
SUPPLY CURRENT (mA)
5
MAX442-05
MAX442-04
0
1
4
OUTPUT VOLTAGE SWING
vs. LOAD RESISTANCE
CROSSTALK
vs. FREQUENCY
CROSSTALK (dB)
VOLTAGE-NOISE DENSITY (nV/√Hz)
1000
OPEN-LOOP VOLTAGE GAIN (dB)
MAX442
140MHz, 2-Channel
Video Multiplexer/Amplifier
2
1
0
-1
-2
-3
-40 -20
0
20
40
60
TEMPERATURE (°C)
_______________________________________________________________________________________
80
100
140MHz, 2-Channel
Video Multiplexer/Amplifier
PIN
NAME
1
IN0
2
GND
3
IN1
FUNCTION
Analog Input, channel 0
Ground
Analog Input, channel 1
4
V-
Negative Power Supply, -5V
5
IN-
Amplifier Inverting Input
6
VOUT
7
V+
Positive Power Supply, +5V
8
A0
Channel Address Input:
A0 = logic 0 selects channel 0,
A0 = logic 1 selects channel 1
Amplifier Output
__________Applications Information
The MAX442’s bipolar construction results in a typical
channel input capacitance of only 4pF, whether the
channel is on or off. As with all ICs, the mux’s input
capacitance forms a single-pole RC lowpass filter with
the signal source’s output impedance. This filter can
limit the system’s signal bandwidth if the RC product
becomes too large. However, the MAX442’s low channel input capacitance allows full AC performance of the
amplifier, even with source impedances as great as
250Ω—a significant improvement over common mux or
switch alternatives.
Feedback resistors should be limited to no more than
500Ω to ensure that the RC time constant formed by the
resistors, the circuit board’s capacitance, and the
capacitance of the amplifier input pins does not limit
the system’s high-speed performance.
To prevent oscillation and unwanted signal coupling,
minimize trace area at the circuit’s critical high-impedance nodes, especially the amplifier summing junction
(the amplifier’s inverting input). Surround these critical
nodes with a ground trace, and include ground traces
between all signal traces to minimize parasitic coupling
that can degrade crosstalk and/or amplifier stability.
Keep signal paths as short as possible to minimize
inductance, and keep all input channel traces at equal
lengths to maintain the phase relationship between the
input channels.
Bypass all power-supply pins directly to the ground
plane with 0.1µF ceramic capacitors, placed as close
to the supply pins as possible. For high-current loads,
it may be necessary to include 1µF tantalum or aluminum-electrolytic capacitors in parallel with the 0.1µF
ceramic bypass capacitors. Keep capacitor lead
lengths as short as possible to minimize series inductance; surface-mount (chip) capacitors are ideal for this
application.
Differential Gain and Phase Errors
In color video applications, lowest differential gain and
phase errors are critical for an IC, because they cause
changes in contrast and color of the displayed picture.
Typically, the MAX442’s multiplexer/amplifier combination has a differential gain and phase error of only
0.07% and 0.09°, respectively. This low differential
gain and phase error makes the MAX442 ideal for use
in broadcast-quality color video systems.
Coaxial-Cable Drivers
High-speed performance and excellent output current
capability make the MAX442 ideal for driving 50Ω or
75Ω coaxial cables. The MAX442 will drive 50Ω and
75Ω coaxial cables to ±3V.
75Ω
CABLE
Power-Supply Bypassing
and Board Layout
Realizing the full AC performance of high-speed amplifiers requires careful attention to power-supply bypassing and board layout. Use a low-impedance ground
plane with the MAX442. With multilayer boards, the
ground plane should be located on the PC board’s
component side to minimize impedance between the
components and the ground plane. For single-layer
boards, components should be mounted on the board’s
copper side and the ground plane should include the
entire portion of the board that is not dedicated to a
specific signal trace.
75Ω
75Ω
75Ω
CABLE
MAX442
75Ω
470Ω
75Ω
CABLE
75Ω
SOURCE:
TEKTRONIX
1910 DIGITAL GENERATOR
470Ω
MEASUREMENT:
TEKTRONIX
VM700 VIDEO
MEASUREMENT SET
Figure 1. Differential Gain and Phase Error Test Circuit
_______________________________________________________________________________________
5
MAX442
_____________________Pin Description
MAX442
140MHz, 2-Channel
Video Multiplexer/Amplifier
The Typical Operating Circuit shows the MAX442 driving a back-terminated 75Ω video cable. The back-termination resistor (at the MAX442 output) is included to
match the impedance of the cable’s driven end to the
characteristic impedance of the cable itself. This, plus
the load-termination resistor, eliminates signal reflections from the cable’s ends. The back-termination resistor forms a voltage divider with the load impedance,
which attenuates the signal at the cable output by onehalf. The amplifier is operated with a 2V/V closed-loop
gain to provide unity gain at the cable’s video output.
lowers. The amplifier’s output impedance and the
capacitive load form an RC filter that adds a pole to the
loop response. If the pole frequency is low enough, as
when driving a large capacitive load, the circuit phase
margin is degraded and oscillation may occur.
With capacitive loads greater than approximately 50pF
and the MAX442 configured as a unity-gain buffer, use
an isolation resistor in series with the load, as shown in
Figure 2. The resistor removes the pole from the loop
response caused by the load capacitance.
Capacitive-Load Driving
When the MAX442 multiplexer is switched from one
channel to another, a small glitch will appear at the output. Figure 3 shows the results of putting a 0V to 5V
pulse 100ns wide into A0.
Driving large capacitive loads increases the likelihood
of oscillation in most amplifier circuits. This is especially true for circuits with high loop gains, like voltage fol-
MAX442
IN
22Ω
Channel Switching Time/Transient
INPUT
1V/div
GND
CABLE
OUTPUT
500mV/div
GND
OUT
CLOAD > 50pF
Figure 4. Pulse Response with RL = 100Ω (50Ω back-terminated
cable), AVCL = +1V/V
Figure 2. Capacitive-Load-Driving Circuit
A0 INPUT
5V/div
GND
AMP
OUTPUT
200mV/div
GND
Figure 3. Output Switching Transient when Switching Between
Two Grounded Inputs with RL = 100Ω
6
INPUT
1V/V
GND
CABLE
OUTPUT
1V/V
GND
Figure 5. Pulse Response with RL = 100Ω (50Ω back-terminated
cable), AVCL = +2V/V
_______________________________________________________________________________________
140MHz, 2-Channel
Video Multiplexer/Amplifier
A0
MAX442
IN0
(MEASURED WITH
CHANNEL 0
SELECTED)
IN1
75Ω
IN0
V+
OUT
0.066"
(1.676mm)
150Ω
A0
V OUT
GND
IN-
IN1
VIN = 1Vp-p at 10MHz,
RS = 75Ω
V0.066"
(1.676mm)

V

CROSSTALK = 20 log10  OUT  
 V IN  

TRANSISTOR COUNT: 137
SUBSTRATE CONNECTED TO V-
Figure 6. Crosstalk Test Circuit
tAPD
A0
VOUT
tSW
Figure 7. Switch Timing
_______________________________________________________________________________________
7
MAX442
___________________Chip Topography
MAX442
140MHz, 2-Channel
Video Multiplexer/Amplifier
________________________________________________________Package Information
D
E
DIM
E1
A
A1
A2
A3
B
B1
C
D1
E
E1
e
eA
eB
L
A3
A A2
L A1
0° - 15°
C
e
B1
eA
B
eB
D1
Plastic DIP
PLASTIC
DUAL-IN-LINE
PACKAGE
(0.300 in.)
INCHES
MAX
MIN
0.200
–
–
0.015
0.175
0.125
0.080
0.055
0.022
0.016
0.065
0.045
0.012
0.008
0.080
0.005
0.325
0.300
0.310
0.240
–
0.100
–
0.300
0.400
–
0.150
0.115
PKG. DIM PINS
P
P
P
P
P
N
D
D
D
D
D
D
8
14
16
18
20
24
INCHES
MIN
MAX
0.348 0.390
0.735 0.765
0.745 0.765
0.885 0.915
1.015 1.045
1.14 1.265
MILLIMETERS
MIN
MAX
–
5.08
0.38
–
3.18
4.45
1.40
2.03
0.41
0.56
1.14
1.65
0.20
0.30
0.13
2.03
7.62
8.26
6.10
7.87
2.54
–
7.62
–
–
10.16
2.92
3.81
MILLIMETERS
MIN
MAX
8.84
9.91
18.67 19.43
18.92 19.43
22.48 23.24
25.78 26.54
28.96 32.13
21-0043A
DIM
D
0°-8°
A
0.101mm
0.004in.
e
B
A1
E
C
L
Narrow SO
SMALL-OUTLINE
PACKAGE
(0.150 in.)
H
A
A1
B
C
E
e
H
L
INCHES
MAX
MIN
0.069
0.053
0.010
0.004
0.019
0.014
0.010
0.007
0.157
0.150
0.050
0.244
0.228
0.050
0.016
DIM PINS
D
D
D
8
14
16
MILLIMETERS
MIN
MAX
1.35
1.75
0.10
0.25
0.35
0.49
0.19
0.25
3.80
4.00
1.27
5.80
6.20
0.40
1.27
INCHES
MILLIMETERS
MIN MAX
MIN
MAX
0.189 0.197 4.80
5.00
0.337 0.344 8.55
8.75
0.386 0.394 9.80 10.00
21-0041A
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
© 1995 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.