Download MAX4141 330MHz, 4x1 Precision Video Multiplexer

19-0400; Rev 0; 5/95
IT
K
ATION
EVALU
BLE
AVAILA
330MHz, 4x1 Precision Video Multiplexer
____________________________Features
♦ 330MHz -3dB Bandwidth
♦ 0.1dB Gain Flatness of 150MHz
♦ 700V/µs Slew Rate
♦ 0.01°/0.01% Differential Phase/Gain
♦ -66dB Crosstalk and -74dB Isolation at 30MHz
♦ High-Z Outputs when Disabled
♦ 3pF Input Capacitance
♦ Low Switching Glitch
♦ On-Board Control Logic
______________Ordering Information
PART
TEMP. RANGE
MAX4141CSD
0°C to +70°C
PIN-PACKAGE
14 SO
________________________Applications
Broadcast/HDTV-Quality Color Signal Multiplexing
Video Routers and Crosspoint Arrays
RF and IF Routing
________________Functional Diagram
Graphics Color Signal Routing
Telecom Routing
IN0
AV = +1
Data Acquisition
IN1
AV = +1
__________________Pin Configuration
OUT
IN2
AV = +1
TOP VIEW
IN0 1
14 A0
GND 2
13 A1
IN1 3
GND 4
IN3
AV = +1
12 VCC
MAX4141
IN2 5
11 OUT
10 VEE
GND 6
9
EN
IN3 7
8
N.C.
A0
A1
CONTROL
LOGIC
EN
SO
________________________________________________________________ Maxim Integrated Products
Call toll free 1-800-998-8800 for free samples or literature.
1
MAX4141
_______________General Description
The MAX4141 is a wideband 330MHz, 700V/µs 4x1
multiplexer optimized for high-definition, broadcastquality, composite (HDTV, NTSC, PAL, SECAM) video
switching arrays. The device includes four open-loop
buffer amplifiers with a 0.1dB gain flatness of 150MHz,
and enable and switch-control logic. The MAX4141
operates from ±5V supplies and features differential
phase and gain error of only 0.01°/0.01%. The ultra-low
switching glitch (less than 13mV) is positive to avoid
confusion with any sync pulses.
Ideal as a building block for large switch arrays, the
MAX4141 features a constant, high input impedance
and a disable function that puts the output into a highimpedance state and reduces the operating current to
only 250µA. The open-loop architecture allows the output to drive capacitive loads without oscillation.
Other key features include -66dB crosstalk (30MHz),
-74dB isolation (30MHz), less than 10mV offset voltage,
and a 110MHz full-power bandwidth (1.4Vp-p). The
MAX4141 is available in a 14-pin narrow SO package.
MAX4141
330MHz, 4x1 Precision Video Multiplexer
ABSOLUTE MAXIMUM RATINGS
VCC ...........................................................................................6V
VEE ..........................................................................................-6V
VCC-VEE..................................................................................12V
Analog Input Voltage .......................(VEE - 0.3V) to (VCC + 0.3V)
Digital Input Voltage ...................................-0.3V to (VCC + 0.3V)
Duration of Short Circuit to Ground..............Continuous (Note 1)
Continuous Power Dissipation (TA = +70°C)
SO (derate 8.00mW/°C above +70°C) ........................640mW
Operating Temperature Range...............................0°C to +70°C
Storage Temperature Range .............................-65°C to +160°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10sec) .............................+300°C
Note 1: If maximum power-dissipation rating is met.
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
(VS = ±5V, -2.5V ≤ VIN ≤ +2.5V, RL = 5kΩ, CL = 5pF, TA = 0°C to +70°C, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
±4.5
±5.0
±5.5
V
5.0
5.5
DC PARAMETERS
Operating Supply Voltage
VS
Operating Supply Current
IS(ON)
Disabled Supply Current
IS(OFF)
Input Voltage Range
Input Bias Current
IB
RIN
Input Capacitance
CIN
Power-Supply Rejection Ratio
Voltage Gain
Output Resistance
Disabled Output Current
TA = TMIN to TMAX
VOS
PSRR
AV
6.5
250
350
Channel selected
±2.5
±4.0
Channel disabled
±0.2
VIN
Input Resistance
Output Offset Voltage
Enabled
TA = +25°C
±2.5
VIN = 0V
0.4
Channel disabled
100
±3
TA = TMIN to TMAX
VIN = ±2.5V
50
0.98
1.0
TA = TMIN to TMAX
0.97
1.0
VOUT = 0V
mV
dB
TA = +25°C
ROUT
IOUT(OFF)
pF
±10
±15
VS = ±4.5V to ±5.5V
µA
MΩ
3
TA = +25°C
µA
V
Channel selected
VIN = 0V, channel enabled or disabled
mA
V/V
20
Ω
10
nA
Disabled Output Resistance
ROUT
30
MΩ
Disabled Output Capacitance
COUT
5
pF
Logic Input High Voltage
VINH
VS = ±4.5V to ±5.5V
Logic Input Low Voltage
VINL
VS = ±4.5V to ±5.5V
0.8
V
Logic Input High Current
IINH
VS = ±4.5V to ±5.5V
10
µA
Logic Input Low Current
IINL
VS = ±4.5V to ±5.5V
10
µA
2
2.0
_______________________________________________________________________________________
V
330MHz, 4x1 Precision Video Multiplexer
MAX4141
ELECTRICAL CHARACTERISTICS (continued)
(VS = ±5V, -2.5V ≤ VIN ≤ +2.5V, RL = 5kΩ, CL = 5pF, TA = 0°C to +70°C, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
AC PARAMETERS
Slew Rate
SR
Full-Power Bandwidth
(Note 2)
fPBW
-3dB Bandwidth
f3dB
Gain Flatness
VIN = 5Vp-p
700
VIN = 1.4Vp-p
500
VIN = 1.4Vp-p
110
VIN = 5Vp-p
45
VIN = 0.1Vp-p
330
DC to 30MHz
0.02
DC to 150MHz
±0.1
Gain Peaking
Small-Signal Rise Time
tR
V/µs
MHz
MHz
dB
0.08
dB
VIN = 0.2Vp-p, 10% to 90%
950
ps
Differential Gain (Note 3)
DG
f = 3.58MHz
0.01
%
Differential Phase (Note 3)
DP
f = 3.58MHz
0.01
degrees
All-Hostile Crosstalk
VIN = 1Vp-p, f = 30MHz, RIN = 50Ω
66
dB
Off Isolation
VIN = 1Vp-p, f = 30MHz
74
dB
µs
Channel Switching Off Time
tOFF
1.0
Channel Switching On Time
tON
500
ns
13
mVp-p
Switching Transient
Group Delay
f = 3.58MHz
860
ps
Input-Output Delay Matching
Chip-to-chip, f = 3.58MHz
±0.2
degrees
Second Harmonic Distortion
f = 30MHz, VIN = 1.4Vp-p, RL = 2k
-65
dBc
Third Harmonic Distortion
f = 30MHz, VIN = 1.4Vp-p, RL = 2k
-70
dBc
Note 2:
Note 3:
Full-Power Bandwidth is inferred from Slew Rate (SR) testing by the equation SR = ωEP, where EP is the peak output
voltage and ω = 2πf.
Differential Gain and Phase are tested using a modulated ramp, 100IRE (0.714V).
MAX4141
MAX4141
HIGH-IMPEDANCE
PROBE
NETWORK
ANALYZER
HIGH-IMPEDANCE
PROBE
NETWORK
ANALYZER
20Ω*
ALL-HOSTILE CROSSTALK TEST CIRCUIT
VIN
(1Vp-p)
VIN
(1Vp-p)
* 20Ω RESISTOR USED TO SIMULATE
OUTPUT RESISTOR OF AN "ON" MAX4141.
IN THIS WAY, OPERATION IN AN ARRAY
IS SIMULATED.
OFF-ISOLATION TEST CIRCUIT
_______________________________________________________________________________________
3
__________________________________________Typical Operating Characteristics
(VS = ±5V, RL = 5kΩ, CL = 1pF, TA = +25°C, unless otherwise noted.)
GAIN FLATNESS
0.1
0
GAIN (dB)
-6
-8
-10
-0.1
-0.2
-0.3
-12
-0.4
-14
-0.5
-16
-0.6
-0.7
-18
1
100
10
10
FREQUENCY (MHz)
0.1
VEE
-50
VCC
40
20
0
-20
-40
-60
-80
20
0
-20
-40
-60
-80
-80
-120
-120
-90
-140
10M
100M
-140
0.1
1
10
100
FREQUENCY (Hz)
FREQUENCY (MHz)
SMALL-SIGNAL PULSE RESPONSE
SMALL-SIGNAL PULSE RESPONSE
0.1
VOLTS
(100mV/div)
1
10
100
1000
FREQUENCY (MHz)
LARGE-SIGNAL PULSE RESPONSE
(CL = 0pF, RL = 5kΩ)
MAX14141 TOC-09
MAX14141 TOC-07
VOLTS
(100mV/div)
1000
(CL = 47pF, RL = ∞)
(CL = 0pF, RL = 5kΩ)
500
40
-100
1M
100
OFF ISOLATION vs. FREQUENCY
-100
100k
10
60
-70
10k
1
FREQUENCY (MHz)
AMPLITUDE (dB)
-30
-60
1000
MAX4141 TOC-05
60
AMPLITUDE (dB)
-20
-40
100
ALL-HOSTILE CROSSTALK
vs. FREQUENCY
MAX4141 TOC-04
0
-10
10
FREQUENCY (MHz)
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
10
20
0
1
1000
30
MAX4141 TOC-06
GAIN (dB)
-4
MAX4141 TOC-03
0.2
40
MAX14141 TOC-08
0
-2
OUTPUT RESISTANCE vs. FREQUENCY
MAX4141 TOC-02
MAX4141 TOC-01
0.3
OUTPUT RESISTANCE (Ω)
GAIN vs. FREQUENCY
2
AMPLITUDE (dB)
MAX4141
330MHz, 4x1 Precision Video Multiplexer
IN
(2.5V/div)
GND
VOLTS
GND
OUT
(1V/div)
TIME (5ns/div)
4
TIME (5ns/div)
TIME (5ns/div)
_______________________________________________________________________________________
330MHz, 4x1 Precision Video Multiplexer
LARGE-SIGNAL PULSE RESPONSE
(CL = 47pF, RL = ∞)
MAX14141 TOC-12
ENABLE ON
GND
AMPLITUDE
IN
2.5V/div
OUTPUT GLITCH AMPLITUDE
MAX14141 TOC-11
MAX14141 TOC-10
ENABLE/DISABLE DELAY TIME
VOLTS
GND
OUT
(1V/div)
OUTPUT
2V/div
GND
IN0 ON
A0
2V/div
1V/div
10mV/div
TIME (10ns/div)
TIME (1µs/div)
TIME (1µs/div)
NOISE VOLTAGE
vs. FREQUENCY
SUPPLY CURRENT
vs. TEMPERATURE
GAIN vs. INPUT VOLTAGE
AND TEMPERATURE
3
TA = 0°C
-0.090
4.6
TA = +25°C
4.4
4.2
IEE
GAIN (dB)
SUPPLY CURRENT (mA)
10
MAX4141 TOC-15
4.8
30
-0.085
MAX4141 TOC-14
5.0
MAX4141 TOC-13
100
ICC
4.0
3.8
-0.095
-0.100
TA = +70°C
-0.105
3.6
1
10k
1M
100M
-0.110
3.4
10G
0
10
FREQUENCY (Hz)
20
30
40
50
60
-3
70
-2
-1
0
1
2
3
INPUT VOLTAGE (V)
TEMPERATURE (°C)
GAIN vs.
LOAD RESISTANCE
BANDWIDTH vs.
LOAD CAPACITANCE
RL = OPEN
300
0
MAX4141 TOC-17
350
-0.2
-0.4
250
GAIN (dB)
100
MAX4141 TOC-16
1
BANDWIDTH (MHz)
NOISE VOLTAGE (nV √Hz)
OUTPUT
200
150
-3dB BW
100
-0.6
-0.8
-1.0
-1.2
50
-1.4
-0.1dB BW
-1.6
0
0
20
40
60
80
LOAD CAPACITANCE (pF)
100
0
1
2
3
4
5
RL(kΩ)
_______________________________________________________________________________________
5
MAX4141
____________________________Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
MAX4141
330MHz, 4x1 Precision Video Multiplexer
______________________________________________________________Pin Description
PIN
FUNCTION
1
IN0
DESCRIPTION
2, 4, 6
GND
3
IN1
Signal Input
5
IN2
Signal Input
7
IN3
Signal Input
8
N.C.
No Connect—not internally connected.
9
EN
Output Enable and device shutdown. A logic high on this pin enables the output. A logic low
causes the output to assume a high-impedance state and reduces operating current.
10
VEE
Negative Power-Supply Voltage. Decouple to power ground.
11
OUT
Signal Output
12
VCC
Positive Power-Supply Voltage. Decouple to power ground.
13
A1
Channel Selection Bit. See truth tables.
14
A0
Channel Selection Bit. See truth tables.
Signal Input
Analog (Signal) Ground. Since inputs are isolated by these grounds, they should be as noise-free
as possible.
_______________Detailed Description
__________Applications Information
The MAX4141 video switch is manufactured with
Maxim’s proprietary complementary bipolar process
that yields high bandwidth and low capacitance. To
maintain a wide bandwidth, the MAX4141 incorporates
a straightforward structure of input and output buffers.
Make-before-break switching is employed to reduce
noise and glitches, even when switching from part to
part in large arrays. The input buffers provide a constant, high input impedance. And, they prevent the
make-before-break action from feeding back to the
input and causing noise and/or glitches.
The design of the switching mechanism limits the
inevitable glitch to within 13mVp-p. In addition, the
glitch pulse is positive to avoid confusion with any negative sync pulses.
Unity-gain output buffers isolate other inputs from the
switching action of large multiplex arrays. These buffers
can drive 5kΩ resistive loads. Load capacitance is limited only by system bandwidth requirements.
The MAX4141 does not contain buffer latches. The digital inputs control the switch transparently.
Grounding, Bypassing,
and PC Board Layout
6
In order to obtain the MAX4141’s full 330MHz bandwidth,
Microstrip and Stripline techniques are recommended in
most cases. To ensure your PC board does not degrade
the switch’s performance, it’s wise to design the board
for a frequency greater than 1GHz. Even with very short
runs, it’s good practice to use this technique at critical
points, such as inputs and outputs. Whether you use a
constant-impedance board or not, observe the following
guidelines when designing the board:
• Do not use wire-wrap boards, because they are too
inductive.
• Do not use IC sockets. They increase parasitic
capacitance and inductance.
• In general, surface-mount components have shorter
leads and lower parasitic reactance, and give better
high-frequency performance than through-hole components.
• The PC board should have at least two layers, with
one side a signal layer and the other a ground plane.
• Keep signal lines as short and as straight as possible. Do not make 90° turns; round all corners.
• The ground plane should be as free from voids as
possible.
_______________________________________________________________________________________
330MHz, 4x1 Precision Video Multiplexer
Bypass Components—Capacitors
Electrolytic and tantalum capacitors are available from
0.1µF to over 300µF, but have resonant frequencies
below 1MHz. Ceramic capacitors are highly recommended and are available to 1µF, with the smaller values having resonant frequencies to almost 1GHz. The
less expensive capacitors are constructed using a
multilayer approach; high values are available, but resonant frequencies beyond a few hundred megahertz
are not, because of the inductive effect of the multiple
layers. More expensive, solid dielectric microwave
porcelain/ceramic capacitors are available up to
1000pF with resonant frequencies beyond 20GHz. In all
types, resonant frequency depends on capacitor value,
voltage rating, and physical size; the larger the capacitor, the lower the resonant frequency.
We recommend ceramic surface-mount/chip capacitors. Placement of bypass capacitors on the PC board
is critical, and the smaller chip capacitors allow placement as close to the part as practical. The smaller,
higher frequency capacitors should be placed as close
to the chip as possible, with the higher-value capacitors placed farther away.
Creating Large Arrays
The MAX4141 was designed as a building block for
large arrays. The high-power drive required for internal
cable drivers has a negative effect on crosstalk and
increases system power consumption. Figure 1 shows
an 8x1 multiplexer circuit.
Even though the MAX4141 drives capacitive loads, you
may want to limit the number of switches connected
together to maximize bandwidth. The MAX4141 has a
finite input capacitance of about 3pF and a dynamic
output resistance of about 20Ω. This causes a pole at a
little more than 2.6GHz. However, in a large array with
many switch inputs, the total capacitance is (N x 3pF),
where “N” is the number of switches connected in parallel. The pole will be located at:
1
(
)
2π × N × 3pF + C STRAY × 20Ω
MHz
where CSTRAY is the stray capacitance from the interconnect.
If the maximum number of switches that may be connected while still maintaining bandwidth is less than
your system requirements, use a unity-gain buffer
amplifier to isolate the switch from the remainder of the
inputs.
Table 1. Truth Table
A1
A0
EN
OUT
X
X
0
High-Z
0
0
1
IN0
0
1
1
IN1
1
0
1
IN2
1
1
1
IN3
_______________________________________________________________________________________
7
MAX4141
On Maxim’s evaluation kit, the ground plane has been
removed from areas where keeping the trace capacitance to a minimum is more important than maintaining
ground continuity. For example, the ground plane has
been removed from beneath the IC to minimize pin
capacitance.
The signal input line is approximately 0.103 inches
wide to minimize inductance and to provide a constant
50Ω impedance path. It is terminated by a 50Ω chip
resistor.
MAX4141
330MHz, 4x1 Precision Video Multiplexer
75Ω
IN0
A0
1
14
GND
A1
2
MAX4141
IN1
1000pF
OUT
4
11
IN2
75Ω
10µF
13
12
GND
75Ω
10µF
VCC
3
75Ω
VEE VCC
VEE
5
10
GND
6
EN
9
IN3
N.C.
8
7
1000pF
OUT
(TO CABLE DRIVER OR
OTHER SWITCHES)
75Ω
IN0
A0
1
14
A1
GND
2
MAX4141
VCC
IN1
3
75Ω
12
1000pF
OUT
GND
4
11
IN2
VEE
5
75Ω
10
GND
1000pF
EN
9
6
75Ω
13
IN3
N.C.
8
7
EN2
EN1
A1
A0
Figure 1. 8x1 Multiplexer Circuit
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.