_______________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 broad-
cast-quality video applications. The device is designed
to drive both 50
and 75
cables, and can directly
drive a 75
load to 3V.
The MAX442 video amplifier is compensated for unity-
gain stability, and features a 140MHz bandwidth and a
250V/s slew rate. The multiplexer's low input capaci-
tance (4pF with the channel on or off) maximizes high-
speed 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 8-
channel mux/amp and the MAX441 4-channel mux/amp.
________________________Applications
Broadcast-Quality Video-Signal Multiplexing
Coaxial-Cable Drivers
Video Editing
Video Security Systems
Medical Imaging
High-Speed Signal Processing
____________________________Features
o
140MHz Unity-Gain Bandwidth
o
250V/s Slew Rate
o
0.07%/0.09 Differential Gain/Phase Error
o
36ns Channel Switch Time
o
No External Compensation Components
o
8-Pin DIP and SO Packages
o
Directly Drives 50
and 75
Cables
______________Ordering Information
*Dice are specified at T
A
= +25C, DC parameters only.
MAX442
140MHz, 2-Channel
Video Multiplexer/Amplifier
________________________________________________________________
Maxim Integrated Products
1
1
2
3
4
8
7
6
5
A0
V+
V
OUT
IN-
V-
IN1
GND
IN0
MAX442
DIP/SO
TOP VIEW
__________________Pin Configuration
MAX442
V
OUT
V+
V-
0.1
F
+5V
-5V
A0
CHANNEL
SELECT
0.1
F
IN-
75
75
75
CABLE
270
IN0
270
VIDEO
OUTPUT
VIDEO
SIGNALS
IN
IN1
GND
__________Typical Operating Circuit
Call toll free 1-800-998-8800 for free samples or literature.
19-0016; Rev 1; 1/95
PART
MAX442CPA
MAX442CSA
MAX442C/D
0C to +70C
0C to +70C
0C to +70C
TEMP. RANGE
PIN-PACKAGE
8 Plastic DIP
8 SO
Dice*
MAX442EPA
MAX442ESA
-40C to +85C
-40C to +85C
8 Plastic DIP
8 SO
MAX442
140MHz, 2-Channel
Video Multiplexer/Amplifier
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V+ = 5V, V- = -5V, R
L
= 150
, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
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 (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 (T
A
= +70C)
Plastic DIP (derate 9.09mW/C above +70C) ............727mW
SO (derate 5.88mW/C above +70C) .........................471mW
Operating Temperature Ranges
MAX442C_A........................................................0C to +70C
MAX442E_A .....................................................-40C to +85C
Storage Temperature Range .............................-65C to +150C
Lead Temperature (soldering, 10sec) .............................+300C
T
A
= +25C
A
V
= 0dB
Channel on or off
V
IN
= 0V
MAX442C
MAX442E
T
A
= +25C
T
A
= T
MIN
to T
MAX
A
V
= 6dB
CONDITIONS
50
mV
1.5
7.0
V
OS
Input Offset Voltage
(All Channels)
V
-2
2
V
IN
Input Voltage Range
m
25
R
OUT
DC Output Resistance
pF
4
C
IN
Input Capacitance
5
A
0.6
2
I
B
Input Bias Current
(Channel On)
10
12
mV
1
2.5
Offset Matching
(V
OS0
V
OS1
)
5.0
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
T
A
= +25C
T
A
= T
MIN
to T
MAX
V
IN
= 0V
1
T
A
= +25C
T
A
= T
MIN
to T
MAX
nA
0.5
50
I
LKG
Input Leakage Current
(Channel Off)
-2V
V
CM
2V
0.2
T
A
= +25C
T
A
= T
MIN
to T
MAX
M
0.5
2.0
R
IN
Input Resistance
(Channel On) (Note 1)
A
R
L
= 75
,
-2V
V
OUT
+2V
46
dB
50
60
A
VOL
Open-Loop Voltage Gain
T
A
= T
MIN
to T
MAX
T
A
= +25C
-2V
V
IN
+2V
46
dB
46
50
CMRR
Common-Mode Rejection Ratio
T
A
= T
MIN
to T
MAX
T
A
= +25C
R
L
= 75
2.0
V
2.5
3.0
V
OUT
Output Voltage Swing
T
A
= T
MIN
to T
MAX
T
A
= +25C
4.75V to 5.25V
54
dB
54
80
PSRR
Power-Supply Rejection Ratio
T
A
= T
MIN
to T
MAX
T
A
= +25C
DC PERFORMANCE
MAX442
140MHz, 2-Channel
Video Multiplexer/Amplifier
_______________________________________________________________________________________
3
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 switch-
ing between channels with different input voltages.
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 5V, V- = -5V, R
L
= 150
, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
V
IN
= 0V
A
V
= 0dB, R
L
= 100
CONDITIONS
mA
25
30
35
I
CC
Positive Supply Current
MHz
140
BW
-3dB Bandwidth
22
38
19
41
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
V/s
250
SR1
Slew Rate
Figure 1
Figure 1
%
0.07
DG
Differential Gain Error
degrees
0.09
DP
Differential Phase Error
To 0.1% of final value,
A
V
= 0dB, R
L
= 150
, 2V step input
ns
50
t
s
Settling Time
f = 10MHz, R
S
= 75
, A
V
= 0dB, Figure 6
f = 10kHz
nV/
Hz
12
e
n
Input Noise-Voltage Density
dB
76
X
TALK
Crosstalk
V
4.75
5.25
V
S
Operating Supply-Voltage Range
T
A
= +25C
MAX442C
MAX442E
V
IN
= 0V
mA
23
28
35
I
EE
Negative Supply Current
20
38
17
41
T
A
= +25C
MAX442C
MAX442E
V
0.8
V
IL
Logic Low Voltage
V
2.4
V
IH
Logic High Voltage
Figure 7 (Note 2)
ns
36
t
SW
Channel Switching Time
Figure 7
ns
24
t
APD
Address Propagation Delay
__________________________________________Typical Operating Characteristics
(T
A
= +25C, unless otherwise noted.)
80
-20
0.001
0.1
10
1000
OPEN-LOOP GAIN AND PHASE
vs. FREQUENCY
0
FREQUENCY (MHz)
OPEN-LOOP GAIN (dB)
PHASE SHIFT (Degrees)
20
40
60
70
50
30
10
-10
135
-315
-225
-270
-180
-90
0
90
-135
-45
45
PHASE
GAIN
30
-20
-15
-5
5
15
25
0.1
1
10
100
1000
CLOSED-LOOP GAIN
vs. FREQUENCY
-10
MAX442-02
FREQUENCY (MHz)
CLOSED-LOOP GAIN (dB)
0
10
20
A
VCL
= 20dB
A
VCL
= 6dB
A
VCL
= 0dB
100
0.01
10k
1M
10M
100k
100M
UNITY-GAIN OUTPUT IMPEDANCE
vs. FREQUENCY
0.1
MAX442-03
FREQUENCY (Hz)
OUTPUT IMPEDANCE (
)
1
10
DYNAMIC PERFORMANCE
POWER REQUIREMENTS
SWITCHING CHARACTERISTICS
MAX442
140MHz, 2-Channel
Video Multiplexer/Amplifier
4
_______________________________________________________________________________________
____________________________Typical Operating Characteristics (continued)
(T
A
= +25C, unless otherwise noted.)
1000
1
1
100
1k
10k
10
100k
VOLTAGE-NOISE DENSITY
vs. FREQUENCY
10
MAX442-04
FREQUENCY (Hz)
VOLTAGE-NOISE DENSITY (nV/
Hz)
100
0
-120
-100
-80
-60
-40
-20
1
10
1000
CROSSTALK
vs. FREQUENCY
MAX442-05
FREQUENCY (MHz)
CROSSTALK (dB)
100
10
100
10k
OUTPUT VOLTAGE SWING
vs. LOAD RESISTANCE
MAX442-06
LOAD RESISTANCE (
)
1k
5
-5
-4
-3
-2
-1
0
1
2
3
4
OUTPUT VOLTAGE (V)
40
-40
-30
-20
-10
0
10
20
30
-40
-20
20
40
60
0
100
SUPPLY CURRENT
vs. TEMPERATURE
MAX442-07
TEMPERATURE (C)
SUPPLY CURRENT (mA)
80
I
CC
I
EE
80
0
10
20
40
30
60
50
70
-40
-20
20
40
60
0
100
OPEN-LOOP VOLTAGE GAIN
vs. TEMPERATURE
MAX442-10
TEMPERATURE (C)
OPEN-LOOP VOLTAGE GAIN (dB)
80
5
-5
-4
-3
-2
-1
1
0
3
2
4
-40
-20
20
40
60
0
100
INPUT OFFSET VOLTAGE
vs. TEMPERATURE
MAX442-08
TEMPERATURE (C)
INPUT OFFSET VOLTAGE (mV)
80
1.0
0
0.1
0.2
0.3
0.4
0.6
0.5
0.8
0.7
0.9
-40
-20
20
40
60
0
100
INPUT BIAS CURRENT
vs. TEMPERATURE
MAX442-09
TEMPERATURE (C)
INPUT BIAS CURRENT (
A)
80
V
CM
= 0V
80
0
10
20
40
30
60
50
70
-40
-20
20
40
60
0
100
COMMON-MODE REJECTION RATIO
vs. TEMPERATURE
MAX442-11
TEMPERATURE (C)
COMMON-MODE REJECTION RATIO (dB)
80
3
-3
-2
-1
1
0
2
-40
-20
20
40
60
0
100
DIFFERENTIAL INPUT OFFSET VOLTAGE
vs. TEMPERATURE
MAX442-12
TEMPERATURE (C)
DIFFERENTIAL INPUT OFFSET VOLTAGE (mV)
80
__________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 chan-
nel input capacitance allows full AC performance of the
amplifier, even with source impedances as great as
250
--a significant improvement over common mux or
switch alternatives.
Feedback resistors should be limited to no more than
500
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.
Power-Supply Bypassing
and Board Layout
Realizing the full AC performance of high-speed ampli-
fiers requires careful attention to power-supply bypass-
ing 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.
To prevent oscillation and unwanted signal coupling,
minimize trace area at the circuit's critical high-imped-
ance 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 0.1F ceramic capacitors, placed as close
to the supply pins as possible. For high-current loads,
it may be necessary to include 1F tantalum or alu-
minum-electrolytic capacitors in parallel with the 0.1F
ceramic bypass capacitors. Keep capacitor lead
lengths as short as possible to minimize series induc-
tance; 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 combina-
tion 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 50
or
75
coaxial cables. The MAX442 will drive 50
and
75
coaxial cables to 3V.
MAX442
140MHz, 2-Channel
Video Multiplexer/Amplifier
_______________________________________________________________________________________
5
_____________________Pin Description
NAME
FUNCTION
1
IN0
Analog Input, channel 0
2
GND
Ground
PIN
3
IN1
Analog Input, channel 1
4
V-
Negative Power Supply, -5V
8
A0
Channel Address Input:
A0 = logic 0 selects channel 0,
A0 = logic 1 selects channel 1
7
V+
Positive Power Supply, +5V
6
V
OUT
Amplifier Output
5
IN-
Amplifier Inverting Input
MAX442
SOURCE:
TEKTRONIX
1910 DIGITAL GENERATOR
75
CABLE
75
CABLE
75
CABLE
75
75
75
75
470
470
MEASUREMENT:
TEKTRONIX
VM700 VIDEO
MEASUREMENT SET
Figure 1. Differential Gain and Phase Error Test Circuit
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