MAX469EWE-T [MAXIM]
Buffer Amplifier, 3 Func, BIPolar, PDSO16, 0.300 INCH, SO-16;
| 型号： | MAX469EWE-T |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Buffer Amplifier, 3 Func, BIPolar, PDSO16, 0.300 INCH, SO-16 光电二极管 |
| 文件： | 总16页 (文件大小：286K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-0219; Rev 2; 6/94
Two-Channel, Triple/Quad
RGB Video Switches and Buffers
_______________General Description
____________________________Features
♦ 100MHz Unity-Gain Bandwidth
♦ 90MHz Bandwidth with 2V/V Gain
♦ 0.01%/0.03° Differential Gain/Phase Error
♦ Drives 50Ω and 75Ω Back-Terminated Cable Directly
The MAX463–MAX470 series of two-channel,
triple/quad buffered video switches and video buffers
combines high-accuracy, unity-gain-stable amplifiers
with high-performance video switches. Fast switching
time and low differential gain and phase error make this
series of switches and buffers ideal for all video appli-
cations. The devices are all specified for ±±5 supply
operation with inputs and outputs as high as ±ꢀ.±5
when driving 1±0Ω loads (7±Ω back-terminated cable).
♦ Wide Output Swing:
2V into 75Ω
2.5V into 150Ω
♦ 300V/µs Slew Rate (2V/V gain)
♦ 20ns Channel Switching Time
Input capacitance is typically only ±pF, and channel-to-
channel crosstalk is better than 60dB, accomplished by
surrounding all inputs with AC ground pins. The on-
board amplifiers feature a ꢀ005/µs slew rate (3005/µs
for A5 = ꢀ5/5 amplifiers), and a bandwidth of 100MHz
(90MHz for A5 = ꢀ5/5 buffers). Channel selection is
controlled by a single TTL-compatible input pin or by a
microprocessor interface, and channel switch time is
only ꢀ0ns.
♦ Logic Disable Mode:
High-Z Outputs
Reduced Power Consumption
♦ Outputs May Be Paralleled for Larger Networks
♦ 5pF Input Capacitance (channel on or off)
______________Ordering Information
For design flexibility, devices are offered with buffer-
amplifier gains of 15/5 or ꢀ5/5 for 7±Ω back-terminated
applications. Output amplifiers have a guaranteed out-
put swing of ±ꢀ5 into 7±Ω.
PART
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +8±°C
-40°C to +8±°C
PIN-PACKAGE
ꢀ4 Narrow Plastic DIP
ꢀ4 Wide SO
MAX463CNG
MAX463CWG
MAX463C/D
MAX463ENG
MAX463EWG
Dice*
Devices offered in this series are as follows:
ꢀ4 Narrow Plastic DIP
ꢀ4 Wide SO
VOLTAGE GAIN
PART
DESCRIPTION
(V/V)
Ordering Information continued on last page.
MAX463
MAX464
MAX46±
MAX466
MAX467
MAX468
MAX469
MAX470
Triple RGB Switch & Buffer
Quad RGB Switch & Buffer
Triple RGB Switch & Buffer
Quad RGB Switch & Buffer
Triple 5ideo Buffer
1
1
ꢀ
ꢀ
1
1
ꢀ
ꢀ
* Dice are specified at T = +25°C, DC parameters only.
A
_________________Pin Configurations
TOP VIEW
IN0A
GND
IN1A
GND
IN2A
V-
1
2
3
4
5
6
7
8
9
24 GND
23 LE
Quad 5ideo Buffer
Triple 5ideo Buffer
MAX463
MAX465
22 EN
Quad 5ideo Buffer
21 A0
20 CS
________________________Applications
19 V-
Broadcast-Quality Color-Signal Multiplexing
V-
18 OUT0
17 V+
RGB Multiplexing
IN0B
GND
RGB Color 5ideo Overlay Editors
RGB Color 5ideo Security Systems
RGB Medical Imaging
16 OUT1
15 GND
14 V+
IN1B 10
GND 11
IN2B 12
Coaxial-Cable Line Drivers
13 OUT2
DIP/SO
Typical Operating Circuit appears at end of data sheet.
Pin Configurations continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products
1
Call toll free 1-800-998-8800 for free samples or literature.
Two-Channel, Triple/Quad
RGB Video Switches and Buffers
ABSOLUTE MAXIMUM RATINGS
Power-Supply Ranges
ꢀ4-Pin Narrow Plastic DIP
5+ to 5- ................................................................................1ꢀ5
Analog Input 5oltage..........................(5- - 0.35) to (5+ + 0.35)
Digital Input 5oltage...................................-0.35 to (5+ + 0.35)
Output Short-Circuit Duration (to GND)........................1 Minute
Input Current into Any Pin, Power On or Off...................±±0mA
(derate ꢀ0.ꢀmW/°C above +70°C)..................................16ꢀ0mW
ꢀ4-Pin Wide SO (derate 19.3mW/°C above +70°C) .........1±90mW
ꢀ8-Pin Narrow Plastic DIP
(derate ꢀ0.ꢀmW/°C above +70°C)..................................16ꢀ0mW
ꢀ8-Pin Wide SO (derate 18.1mW/°C above +70°C) .........1440mW
Operating Temperature Ranges
Continuous Power Dissipation (T = +70°C)
A
16-Pin Plastic DIP (derate ꢀꢀ.ꢀꢀmW/°C above +70°C) ....1778mW
16-Pin Wide SO (derate ꢀ0.00mW/°C above +70°C) .......1600mW
MAX4_ _C_ _.........................................................0°C to +70°C
MAX4_ _E_ _......................................................-40°C to +8±°C
Storage Temperature Range.............................-6±°C to +1±0°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
(5+ = ±5, 5- = -±5, -ꢀ5 ≤ 5 ≤ +ꢀ5, R
= 7±Ω, unless otherwise noted.)
LOAD
IN
T
= +25°C
T
A
= T
MIN
to T
A
MIN MAX
PARAMETER
SYMBOL
CONDITIONS
UNITS
MIN TYP MAX
MAX
±±.ꢀ±
ꢀ
Operating Supply 5oltage
Input 5oltage Range
Offset 5oltage
5
S
±4.7± ±± ±±.ꢀ±
±4.7±
-ꢀ
5
5
-ꢀ
ꢀ
5
IN
5
±3
60
±1
±10
±1±
m5
dB
µA
kΩ
pF
OS
Power-Supply Rejection Ratio
On Input Bias Current
On Input Resistance
Input Capacitance
PSRR
±0
±0
I
±3
±±
BIAS
R
C
300 700
±
1±0
IN
Channel off or on
IN
MAX463/MAX464, MAX467/MAX468
(Note 1)
0.ꢀ
0.3
0.±
1.0
1.0
ꢀ.0
5oltage-Gain Accuracy
Output 5oltage Swing
%
5
MAX46±/MAX466, MAX469/MAX470,
R
R
R
= 1±0Ω, (Note ꢀ)
LOAD
LOAD
LOAD
= 1±0Ω
±ꢀ.± ±ꢀ.8
±ꢀ.0 ±ꢀ.4
±
±ꢀ.±
5
R
OUT
= 7±Ω
-1.±/+ꢀ
f
IN
= 10MHz
MAX463/MAX464,
0.0±
0.1
Output Impedance
MAX467/MAX468
Ω
OUT
f
IN
= DC
MAX46±/MAX466,
MAX469/MAX470
MAX463/MAX464
MAX46±/MAX466
1±0
0.7
ꢀ±0
1
100
0.7
kΩ
kΩ
Output Resistance,
Disabled Mode
R
C
OUTD
Output Capacitance,
Disabled Mode
MAX463–MAX466
10
6±
8±
pF
OUTD
MAX463/MAX46±/MAX467/MAX469,
= 05
80
100
1ꢀ0
5
IN
MAX464/MAX466/MAX468/MAX470,
= 05
100
Positive Supply Current
I+
mA
5
IN
MAX463/MAX46±, disabled mode
MAX464/MAX466, disabled mode
3±
40
4±
±0
±0
±±
2
_______________________________________________________________________________________
Two-Channel, Triple/Quad
RGB Video Switches and Buffers
ELECTRICAL CHARACTERISTICS (continued)
(5+ = ±5, 5- = -±5, -ꢀ5 ≤ 5 ≤ +ꢀ5, R
= 7±Ω, unless otherwise noted.)
LOAD
IN
T
= +25°C
T
= T
MIN
to T
MAX
A
A
MIN MAX
PARAMETER
SYMBOL
CONDITIONS
UNITS
MIN TYP MAX
MAX463/MAX46±/MAX467/MAX469,
±0
6±
6±
80
7±
5
IN
= 05
MAX464/MAX466/MAX468/MAX470,
= 05
9±
Negative Supply Current
I-
mA
5
IN
MAX463/MAX46±, disabled mode
MAX464/MAX466, disabled mode
ꢀ0
ꢀ±
30
3±
3±
40
–—
Input Noise Density
Slew Rate
en
f
IN
= 10kHz
ꢀ0
n5/√Hz
MAX463/MAX464, MAX467/MAX468
MAX46±/MAX466, MAX469/MAX470
MAX463/MAX464, MAX467/MAX468
MAX46±/MAX466, MAX469/MAX470
MAX463/MAX464, MAX467/MAX468
MAX46±/MAX466, MAX469/MAX470
MAX463/MAX464, MAX467/MAX468
MAX46±/MAX466, MAX469/MAX470
ꢀ00
300
100
90
SR
BW
DG
DP
5/µs
MHz
%
-3dB Bandwidth
0.01
0.1ꢀ
0.03
0.14
±0
Differential Gain Error
(Note 3)
Differential Phase Error
(Note 3)
deg.
ns
Settling Time to 0.1%
t
5
IN
= ꢀ5-to-05 step
S
Adjacent Channel Crosstalk
(Note 4)
XTALK
f
IN
= 10MHz
60
dB
All-Hostile Crosstalk (Note ±) XTALK
f
f
= 10MHz
±0
70
dB
dB
IN
All-Hostile Off Isolation (Note 6)
ISO
= 10MHz, MAX463–MAX466
IN
Channel Switching
Propagation Delay (Note 7)
t
MAX463–MAX466
MAX463–MAX466
1±
ns
ns
PD
Channel Switching Time
(Note 8)
t
ꢀ0
300
80
SW
Switching Transient
5
INA
= 5
= 05, MAX463–MAX466
m5
P-P
INB
Amplifier Switching Off-Time
(Note 9)
t
MAX463–MAX466
ns
OFF
Amplifier Switching On-Time
(Note 10)
t
MAX463–MAX466
100
ns
ON
—–
—–
Logic Input High Threshold
Logic Input Low Threshold
Logic Input Current High
Logic Input Current Low
5
EN, A0, CS, LE; MAX463–MAX466
ꢀ
ꢀ
5
5
IH
—– —–
5
EN, A0, CS, LE; MAX463–MAX466
—– —–
0.8
0.8
IL
I
EN, A0, CS, LE; MAX463–MAX466
—– —–
ꢀ00
ꢀ00
ꢀ00
ꢀ00
µA
µA
INHI
I
EN, A0, CS, LE; MAX463–MAX466
INLO
_______________________________________________________________________________________
3
Two-Channel, Triple/Quad
RGB Video Switches and Buffers
ELECTRICAL CHARACTERISTICS (continued)
(5+ = ±5, 5- = -±5, -ꢀ5 ≤ 5 ≤ +ꢀ5, R
= 7±Ω, unless otherwise noted.)
LOAD
IN
T
= +25°C
T
= T
MIN
to T
MAX
A
A
MIN MAX
PARAMETER
SYMBOL
CONDITIONS
UNITS
MIN TYP MAX
—–
—–
Address Setup Time (Note 11)
Address Hold Time (Note 11)
t
EN, A0, CS, LE; MAX463–MAX466
30
30
ns
ns
ns
SU
—–
—–
t
H
EN, A0, CS, LE; MAX463–MAX466
—– —–
0
0
—–
CS Pulse Width Low (Note 11)
t
EN, A0, CS, LE; MAX463–MAX466
1±
1±
CS
Note 1: 5oltage gain accuracy for the unity-gain devices is defined as [(5
Note 2: 5oltage gain accuracy for the gain-of-two devices is defined as [(5
- 5 ) at 5 = 15 - (5
- 5 ) at 5 = -15]/ꢀ.
/ꢀ - 5 ) at 5 = -15]/ꢀ.
OUT IN IN
OUT
IN
IN
OUT IN IN
/ꢀ - 5 ) at 5 = 15 - (5
OUT
IN
IN
Note 3: Tested with a 3.±8MHz sine wave of amplitude 40IRE superimposed on a linear ramp (0IRE to 100IRE), R = 1±0Ω to ground.
L
Note 4: Tested with the selected input connected to ground through a 7±Ω resistor, and a 45 sine wave at 10MHz driving adjacent input.
P-P
Note 5: Tested in the same manner as described in Note 4, but with all other inputs driven.
—–
Note 6: Tested with LE = 05, EN = 5+, and all inputs driven with a 45 , 10MHz sine wave.
P-P
Note 7: Measured from a channel switch command to measurable activity at the output.
Note 8: Measured from where the output begins to move to the point where it is well defined.
Note 9: Measured from a disable command to amplifier in a non-driving state.
Note 10: Measured from an enable command to the point where the output reaches 90% current out.
Note 11: Guaranteed by design.
__________________________________________Typical Operating Characteristics
(T = +ꢀ±°C, unless otherwise noted.)
A
MAX468
MAX464
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
OUTPUT IMPEDANCE
vs. FREQUENCY
MAX468
GAIN AND PHASE RESPONSES
100
10
1
60
50
40
30
2
1
V–
GAIN
0
0
V+
PHASE
–1
36
72
0.1
108
144
180
20
10
–2
–3
0.01
10k
100k
1M
10M 100M
1G
1k
10k
100k
1M
10M 100M
10k
100k
1M
10M
100M
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
4
_______________________________________________________________________________________
Two-Channel, Triple/Quad
RGB Video Switches and Buffers
____________________________Typical Operating Characteristics (continued)
(T = +ꢀ±°C, unless otherwise noted.)
A
MAX463
DISABLED OUTPUT RESISTANCE
vs. TEMPERATURE
MAX465
DISABLED OUTPUT RESISTANCE
vs. TEMPERATURE
VOLTAGE GAIN ACCURACY
vs. TEMPERATURE
400
350
300
0.16
1.30
1.25
1.20
0.14
MAX465
0.12
0.10
MAX463
250
200
1.15
1.10
0.08
0.06
–50 –25
0
25
50
75
100
–50 –25
0
25
50
75
100
–50 –25
0
25
50
75
100
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
DISABLED SUPPLY CURRENT
vs. TEMPERATURE
SUPPLY CURRENT PER AMPLIFIER
vs. TEMPERATURE
OUTPUT VOLTAGE SWING
vs. LOAD RESISTANCE
40
35
30
25
4
30
25
3
2
I+
I–
I+
I–
20
15
10
5
1
MAX463/4/7/8:V
MAX465/6/9/70:V
=
IN
4V
2V
IN
0
=
–1
–2
20
15
10
–3
–4
0
–50 –25
0
25
50
75
100
–50 –25
0
25
50
75
100
10
100
1000
10000
LOAD RESISTANCE (Ω)
TEMPERATURE (°C)
TEMPERATURE (°C)
_______________________________________________________________________________________
5
Two-Channel, Triple/Quad
RGB Video Switches and Buffers
____________________________Typical Operating Characteristics (continued)
(T = +ꢀ±°C, unless otherwise noted.)
A
MAX464
MAX466
SMALL-SIGNAL STEP RESPONSE
SMALL-SIGNAL STEP RESPONSE
A: V
,
A: V ,
IN
IN
GND
GND
GND
GND
100mV/div
100mV/div
B: V
,
B: V
,
OUT
OUT
100mV/div
200mV/div
10ns/div
10ns/div
MAX466
MAX464
LARGE-SIGNAL STEP RESPONSE
LARGE-SIGNAL STEP RESPONSE
GND
GND
GND
GND
A: V
,
IN
A: V
,
IN
1V/div
2V/div
B: V
,
OUT
B: V
,
OUT
2V/div
2V/div
20ns/div
20ns/div
MAX464
OUTPUT TRANSIENT WHEN SWITCHING
BETWEEN TWO GROUNDED INPUTS
MAX464
EN RESPONSE TIME
A: CS,
5V/div
A: CS,
5V/div
GND
GND
GND
GND
B: A0,
5V/div
B: EN,
5V/div
GND
GND
C: OUT0,
C: OUT3,
1V/div
100mV/div
50ns/div
50ns/div
t
t
OFF
ON
6
_______________________________________________________________________________________
Two-Channel, Triple/Quad
RGB Video Switches and Buffers
_____________________________________________________________Pin Descriptions
PIN
NAME
IN0A
FUNCTION
MAX463/MAX465 MAX464/MAX466
1
ꢀ8
Channel A, Analog Input 0
Analog Ground
ꢀ, 4, 9,
11, 1±, ꢀ4
1, 3, ±,
11, 13, 19
GND
3
ꢀ
IN1A
INꢀA
IN3A
5-
Channel A, Analog Input 1
Channel A, Analog Input ꢀ
Channel A, Analog Input 3
±
4
–
6, 7, 19
8
6
7, 9, ꢀ1, ꢀ3
Negative Power-Supply Input. Connect to -±5. Thermal path.
Channel B, Analog Input 0
8
10
IN0B
IN1B
INꢀB
IN3B
OUT3
OUTꢀ
5+
10
Channel B, Analog Input 1
1ꢀ
1ꢀ
Channel B, Analog Input ꢀ
–
14
Channel B, Analog Input 3
–
1±
Buffered Analog Output 3
13
17
Buffered Analog Output ꢀ
14, 17
16
16, 18
ꢀ0
Positive Power-Supply Input. Connect to +±5.
Buffered Analog Output 1
OUT1
OUT0
18
ꢀꢀ
Buffered Analog Output 0
–—–
—–
Chip-Select—latch control for the digital inputs. When CS is low, A0 and EN
–—–
CS
—–
ꢀ0
ꢀ4
input registers are transparent. When CS goes high, the A0 input register latches.
—–
—–
If LE is high, the EN input register also latches when CS goes high (see LE).
—–
Channel-Select Input. When CS is low, driving A0 low selects channel A
and driving A0 high selects channel B.
ꢀ1
ꢀꢀ
ꢀ±
ꢀ6
A0
—–
—–
—–
Buffer-Enable Input. When CS is low or LE is low, driving EN low enables
all output buffers and driving EN high disables all output buffers.
–—–
EN
—–
Digital Latch-Enable Input. When LE is low, the EN register is transparent;
—–
—–
ꢀ3
ꢀ7
LE
when LE is high, the EN register is transparent only when CS is low. Hard-
wire to 5+ or GND for best crosstalk performance.
PIN
MAX467/MAX469 MAX468/MAX470
NAME
FUNCTION
1
1
IN0
GND
IN1
Analog Input 0
ꢀ, 7, 8, 9, 1±
ꢀ, 7, 1±
Analog Ground
3
3
Analog Input 1
4, ±, 1ꢀ, 13
4, ±, 1ꢀ, 13
5-
Negative Power-Supply Input. Connect to -±5. Thermal path.
Analog Input ꢀ
6
–
6
8
INꢀ
IN3
Analog Input 3
–
9
OUT3
5+
Buffered Analog Output 3
Positive Power-Supply Input. Connect to +±5.
Buffered Analog Output ꢀ
Buffered Analog Output 1
Buffered Analog Output 0
10
11
14
16
10
11
14
16
OUTꢀ
OUT1
OUT0
_______________________________________________________________________________________
7
Two-Channel, Triple/Quad
RGB Video Switches and Buffers
_______________Detailed Description
The MAX463–MAX470 have a bipolar construction,
which results in a typical channel input capacitance of
COAX
only ±pF, whether the channel is on or off. This low
input capacitance allows the amplifiers to realize full
AC performance, even with source impedances as
great as ꢀ±0Ω. It also minimizes switching transients
because the driving source sees the same load
whether the channel is on or off. Low input capaci-
RT
RETURN
CURRENT
COAX
tance is critical, because it forms a single-pole RC low-
pass filter with the output impedance of the signal
source, and this filter can limit the system’s signal
bandwidth if the RC product becomes too large.
RT
RETURN
CURRENT
The MAX46±/MAX466/MAX469/MAX470’s amplifiers are
internally configured for a gain of two, resulting in an over-
all gain of one at the cable output when driving back-ter-
minated coaxial cable (see the section Driving Coaxial
Cable). The MAX463/MAX464/MAX467/MAX468 are
internally configured for unity gain.
Figure 1. Low-Crosstalk Layout. Return current from the
termination resistor does not flow through the ground plane.
Connect all 5- pins to a large power plane. The 5- pins
conduct heat away from the internal die, aiding thermal
dissipation.
Power-Supply Bypassing and Board Layout
To realize the full AC performance of high-speed ampli-
fiers, pay careful attention to power-supply bypassing
and board layout, and use a large, low-impedance
ground plane. With multi-layer boards, the ground
plane should be located on the layer that is not dedi-
cated to a specific signal trace.
Differential Gain and Phase Errors
Differential gain and phase errors are critical specifica-
tions for an amplifier/buffer in color video applications,
because these errors correspond directly to changes in
the color of the displayed picture in composite video
systems. The MAX467–MAX470 have low differential
gain and phase errors, making them ideal in broadcast-
quality composite color applications, as well as in RGB
video systems where these errors are less significant.
To prevent unwanted signal coupling, minimize the
trace area at the circuit's critical high-impedance
nodes, and surround the analog inputs with an AC
ground trace (analog ground, bypassed DC power
supply, etc). The analog input pins to the
MAX463–MAX470 have been separated with AC
ground pins (GND, 5+, 5-, or a hard-wired logic input)
to minimize parasitic coupling, which can degrade
crosstalk and/or stability of the amplifier. Keep signal
paths as short as possible to minimize inductance,
and ensure that all input channel traces are of equal
length to maintain the phase relationship between the
R, G, and B signals. Connect the coaxial-cable shield
to the ground side of the 7±Ω terminating resistor at
the ground plane to further reduce crosstalk (see
Figure 1).
The MAX467–MAX470 differential gain and phase errors
are measured with the Tektronix 5M700 5ideo
Measurement Set, with the input test signal provided by
the Tektronix 1910 Digital Generator as shown in Figure ꢀ.
Measuring the differential gain and phase of the
MAX469/MAX470 (Figure ꢀa) is straightforward because
the output amplifiers are configured for a gain of two,
allowing connection to the 5M700 through a back-termi-
nated coaxial cable. Since the MAX467/MAX468 are
unity-gain devices, driving a back-terminated coax
would result in a gain of 1/ꢀ at the 5M700.
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 10µF tantalum or alu-
minum-electrolytic capacitors in parallel with the 0.1µF
ceramics. Keep capacitor lead lengths as short as
possible to minimize series inductance; surface-mount
(chip) capacitors are ideal.
Figure ꢀb shows a test method to measure the differen-
tial gain and phase for the MAX467/MAX468. First,
measure and store the video signal with the device
under test (DUT) removed and replaced with a short
circuit, and the 1±0Ω load resistor omitted. Then do
another measurement with the DUT and load resistor in
the circuit, and calculate the differential gain and phase
errors by subtracting the results.
8
_______________________________________________________________________________________
Two-Channel, Triple/Quad
RGB Video Switches and Buffers
75Ω CABLE
(a)
75Ω
MAX469/MAX470
75Ω CABLE
75Ω CABLE
75Ω
DUT
75Ω
SOURCE:
TEKTRONIX
75Ω
MEASUREMENT:
TEKTRONIX VM700
VIDEO MEASUREMENT
1910 DIGITAL GENERATOR
SET
MAX467/MAX468
(b)
75Ω CABLE
75Ω
75Ω CABLE
75Ω
A = 2
V
DUT
75Ω
150Ω
Figure 2. Differential Phase and Gain Error Test Circuits (a) for the MAX469/MAX470 Gain-of-Two Amplifiers, (b) for the
MAX467/MAX468 Unity-Gain Amplifiers
The MAX463–MAX470 phase margin and capacitive-
load driving performance are optimized by internal
compensation. When driving capacitive loads greater
than ±0pF, connect an isolation resistor between the
amplifier output and the capacitive load, as shown in
Figure 3.
Driving Coaxial Cable
High-speed performance, excellent output current
capability, and an internally fixed gain of two make the
MAX46±/MAX466/MAX469/MAX470 ideal for driving
±0Ω or 7±Ω back-terminated coaxial cables. The
MAX46±/MAX466/MAX469/MAX470 will drive a 1±0Ω
load (7±Ω back-terminated cable) to ±ꢀ.±5.
The Typical Operating Circuit shows the MAX46±/MAX466
driving four back-terminated 7±Ω video cables. The
back-termination resistor (at each amplifier output) pro-
vides impedance matching at the driven end of the
cable to eliminate signal reflections. It forms a voltage
divider with the load impedance, which attenuates the
signal at the cable output by one-half. The amplifier
operates with an internal ꢀ5/5 closed-loop gain to pro-
vide unity gain at the cable’s output.
A
= 1
V
12Ω
OUT_
100pF
IN_
Driving Capacitive Loads
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 follow-
ers. The amplifier’s output impedance and the capaci-
tive 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.
MAX468
Figure 3a. Using an Isolation Resistor with a Capacitive Load
_______________________________________________________________________________________
9
Two-Channel, Triple/Quad
RGB Video Switches and Buffers
MAX468 (WITH ISOLATION RESISTOR)
MAX468 (NO ISOLATION RESISTOR)
A
B
A
B
GND
GND
GND
GND
1μs/div
= 12Ω
1μs/div
C
= 100pF
LOAD
C
= 100pF, R
ISOLATION
LOAD
A: V , 500mV/div
IN
A: V , 500mV/div
IN
B: V , 500mV/div
OUT
B: V , 500mV/div
OUT
Figure 3b. Step Response without an Isolation Resistor
Figure 3c. Step Response with an Isolation Resistor
disabled MAX463/MAX464 outputs exhibit a ꢀ±0kΩ
typical resistance. Because their internal feedback
resistors are required to produce a gain of two, the
MAX46±/MAX466 exhibit a 1kΩ disabled output resis-
tance.
Digital Interface
The MAX463–MAX466 multiplexer architecture provides
an input transistor buffer, ensuring that no input chan-
nels are ever connected together. Select a channel by
changing A0's state (A0 = 0 for channel A, and A0 = 1
—–
—–
—–
for channel B) and pulsing CS low (see Tables 1a, 1b).
LE determines whether EN is latched by CS or operates
independently. When the latch-enable input (LE) is con-
Figure 4 shows the logic timing diagram.
—–
—–
nected to 5+, CS becomes the latch control for the EN
Output Disable (MAX463–MAX466)
—–
—–
—–
input register. If CS is low, both the EN and A0 registers
are transparent; once CS returns high, both registers
When the enable input (EN) is driven to a TTL low state, it
—–
—–
enables the MAX463–MAX466 amplifier outputs. When EN
are latched.
is driven high, it disables the amplifier outputs. The
tCS
CS
tH
tSU
A0
tH
tSU
EN
tON
tOFF
HIGH-Z
OUTPUTS
tSW
LE = V+
tPD
Figure 4. Logic Timing Diagram
10 ______________________________________________________________________________________
Two-Channel, Triple/Quad
RGB Video Switches and Buffers
Table 1a. Amplifier and Channel Selection
with LE = V+
Table 1b. Amplifier and Channel Selection
with LE = GND
—–
—–
—–
—–
CS
EN
A0
FUNCTION
CS
EN
A0
FUNCTION
Enables amplifier outputs.
Selects channel A.
Enables amplifier outputs.
Selects channel B.
Enables amplifier outputs.
Selects channel A.
Enables amplifier outputs.
Selects channel B.
Disables amplifiers. Outputs high-Z.
A0 register = channel A
Disables amplifiers. Outputs high-Z.
A0 register = channel B
0
0
0
0
0
0
0
0
0
1
1
0
0
0
1
0
1
X
1
X
X
1
0
1
Disables amplifiers. Outputs high-Z.
Latches all input registers.
Changes nothing.
Enables amplifier outputs, latches A0
register, programs outputs to output A
1
1
0
1
X
X
or B, according to the setting of A0 at
—–
CS's last edge.
Disables amplifiers. Outputs high-Z.
—–
When LE is connected to ground, the EN register is
Another option for output disable is to connect LE to 5+,
—–
transparent and independent of CS activity. This allows
parallel the outputs of several MAX463-MAX466s, and use
—–
all MAX463–MAX466 devices to be simultaneously shut
EN to individually disable all devices but the one in use
—–
down, regardless of the CS input state. Simply connect
(Figure ±b).
—–
LE to ground and connect all EN inputs together (Figure
When the outputs are disabled, the off isolation from
the analog inputs to the amplifier outputs is typically
±a). For the MAX464 and MAX466, LE must be hard-
wired to either 5+ or ground (rather than driving LE with
a gate) to prevent crosstalk from the digital inputs to
IN0A.
70dB at 10MHz, all inputs driven with a 45
sine
P-P
wave and a 1±0Ω load impedance. Figure 6 shows the
test circuits used to measure isolation and crosstalk.
EN
MAX463–
MAX466
AO
MAX463–
MAX466
LE
CS
+5V
LE
SHUTDOWN
EN
EN
AO
MAX463–
LE MAX466
MAX463–
MAX466
CS
+5V
LE
EN
NOTE: ISOLATION RESISTORS,
(a)
(b)
IF REQUIRED, NOT SHOWN.
–—–
–—–
Figure 5. (a) Simultaneous Shutdown of all MAX463–MAX466, (b) Enable (EN) Register Latched by CS
______________________________________________________________________________________ 11
Two-Channel, Triple/Quad
RGB Video Switches and Buffers
MAX467–MAX470
MAX467–MAX470
150Ω
150Ω
75Ω
75Ω
V
IN
= 4V
P-P
AT 10MHz,
R = 75Ω
S
*
*
V
IN
= 4V
P-P
AT 10MHz,
R = 75Ω
S
(a)
(b)
MAX463–MAX466
MAX463–MAX466
75Ω
150Ω
150Ω
150Ω
150Ω
150Ω
150Ω
150Ω
150Ω
*
*
LE
EN
+5V
V
IN
= 4V AT 10MHz,
P-P
V
= 4V AT 10MHz,
P-P
IN
R = 75Ω
S
R = 75Ω
S
(c)
(d)
* MAX464/MAX466/MAX468/MAX470 ONLY
Figure 6. (a) MAX467–MAX470 Adjacent Channel Crosstalk, (b) MAX467–MAX470 All-Hostile Crosstalk, (c) MAX463–MAX466
All-Hostile Off Isolation, (d) MAX463–MAX466 All-Hostile Crosstalk
12 ______________________________________________________________________________________
Two-Channel, Triple/Quad
RGB Video Switches and Buffers
75Ω
28
27
26
25
24
23
IN0A
1
2
3
4
5
6
GND
IN1A
LE
EN
A0
CS
V–
+5V
MAX470
75Ω
75Ω
75Ω
MAX464
GND
IN2A
–5V
OUT0 22
1
2
IN0
OUT0 16
GND
IN3A
75Ω
–5V
75Ω
75Ω
21
15
GND
IN1
GND
V–
7
8
V–
OUT1 20
3
OUT1 14
–5V
75Ω
–5V
IN0B
75Ω
75Ω
19
75Ω
75Ω
75Ω
4
5
13
GND
9
–5V
–5V
V–
V–
–5V
V–
18
V+
12
+5V
V–
V–
–5V
10
IN1B
OUT2 17
6
7
IN2
OUT2 11
75Ω
11
12
75Ω
+5V
75Ω
GND
IN2B
16
V+
10
V+
GND
IN3
V+
75Ω
OUT3 15
8
OUT3
9
13
GND
75Ω
75Ω
14 IN3B
75Ω
75Ω
28
27
26
25
24
23
IN0A
1
GND
LE
EN
A0
CS
V–
+5V
–5V
2
3
4
5
6
IN1A
75Ω
75Ω
75Ω
MAX464
GND
IN2A
OUT0 22
GND
IN3A
75Ω
–5V
21
V–
7
8
V–
OUT1 20
–5V
75Ω
–5V
IN0B
75Ω
19
GND
9
V–
18
V+
+5V
10
IN1B
OUT2 17
75Ω
75Ω
75Ω
11
12
75Ω
+5V
GND
IN2B
16
V+
OUT3 15
13
GND
75Ω
14 IN3B
FROM OTHER
MAX464s
Figure 7. Higher-Order RGB + Sync Video Multiplexer
______________________________________________________________________________________ 13
Two-Channel, Triple/Quad
RGB Video Switches and Buffers
A1
A0
CS
75Ω
28
27
26
25
24
23
IN0A
1
2
3
4
5
6
GND
IN1A
LE
EN
A0
CS
V–
+5V
75Ω
75Ω
75Ω
MAX466
GND
IN2A
–5V
OUT0 22
GND
IN3A
22Ω
–5V
50Ω
75Ω
21
V–
7
8
V–
OUT1 20
–5V
75Ω
–5V
IN0B
22Ω
50Ω
50Ω
50Ω
19
75Ω
75Ω
75Ω
GND
9
V–
18
V+
+5V
10
IN1B
OUT2 17
75Ω
11
12
22Ω
+5V
GND
IN2B
16
V+
75Ω
OUT3 15
13
GND
22Ω
14 IN3B
75Ω
75Ω
28
27
26
25
24
23
IN0A
1
GND
LE
EN
A0
CS
V–
+5V
–5V
2
3
4
5
6
IN1A
75Ω
75Ω
75Ω
MAX466
GND
IN2A
OUT0 22
GND
IN3A
22Ω
–5V
21
V–
7
8
V–
OUT1 20
–5V
75Ω
–5V
IN0B
22Ω
19
GND
9
V–
18
V+
+5V
10
IN1B
OUT2 17
75Ω
11
12
22Ω
+5V
GND
IN2B
16
V+
75Ω
75Ω
OUT3 15
13
GND
22Ω
14 IN3B
Figure 8. 1-of-4 RGB + Sync Video Multiplexer
14 ______________________________________________________________________________________
Two-Channel, Triple/Quad
RGB Video Switches and Buffers
Paralleling MAX466s to Switch
__________Applications Information
1-of-4 RGB + Sync Signal Inputs
Figure 8 shows a 1-of-4 RGB + sync video mux/amp
circuit. The 1kΩ disabled output resistance limits the
number of paralleled MAX46±/MAX466s to no more
than two. The amplifier outputs are connected after a
ꢀꢀΩ isolation resistor and ahead of a ±0Ω back-termi-
nation resistor, which isolates the active amplifier out-
put from the capacitive load (±pF typ) presented by the
inactive output of the second MAX466. Impedance
mismatching is minimal, and the signal gain at the
cable end is near 1. This minimizes ringing in the out-
put signals. For multiplexing more than two devices,
see the section Higher Order RGB + Sync Video
Multiplexing, above.
Higher-Order RGB + Sync
Video Multiplexing
Higher-order RGB video multiplexers can be realized
by paralleling several MAX463/MAX464s. Connect LE
—–
—–
to 5+ and use CS and EN to disable all devices but the
one in use. Since the disabled output resistance of the
MAX463/MAX464 is ꢀ±0kΩ, several devices may be
paralleled to form larger RGB video multiplexer arrays
without signal degradation. Connect series resistors at
each amplifier's output to isolate the disabled output
capacitance of each paralleled device, and use a
MAX469 or MAX470 to drive the output coaxial cables
(see Figure 7).
_____________________________________________Pin Configurations (continued)
TOP VIEW
GND
IN1A
GND
IN2A
GND
IN3A
V-
1
2
3
4
5
6
7
8
9
28 IN0A
27 LE
IN0
GND
IN1
V-
1
2
3
4
5
6
7
8
16 OUT0
15 GND
14 OUT1
13 V-
IN0
GND
IN1
V-
1
2
3
4
5
6
7
8
16 OUT0
15 GND
14 OUT1
13 V-
MAX464
MAX466
26 EN
25 A0
24 CS
V-
12 V-
V-
12 V-
23 V-
IN2
GND
GND
11 OUT2
10 V+
IN2
GND
IN3
11 OUT2
10 V+
22 OUT0
21 V-
IN0B
V-
9
GND
9
OUT3
20 OUT1
19 GND
18 V+
DIP/SO
DIP/SO
IN1B 10
GND 11
IN2B 12
GND 13
IN3B 14
MAX468
MAX470
QUAD
17 OUT2
16 V+
MAX467
MAX469
TRIPLE (RGB)
BUFFERS
BUFFERS
15 OUT3
DIP/SO
______________________________________________________________________________________ 15
Two-Channel, Triple/Quad
RGB Video Switches and Buffers
__________Typical Operating Circuit
_Ordering Information (continued)
PART
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +8±°C
-40°C to +8±°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +8±°C
-40°C to +8±°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +8±°C
-40°C to +8±°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +8±°C
-40°C to +8±°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +8±°C
-40°C to +8±°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +8±°C
-40°C to +8±°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +8±°C
-40°C to +8±°C
PIN-PACKAGE
ꢀ8 Narrow Plastic DIP
ꢀ8 Wide SO
Dice*
MAX464CNI
MAX464CWI
MAX464C/D
MAX464ENI
MAX464EWI
MAX465CNG
MAX46±CWG
MAX46±C/D
MAX46±ENG
MAX46±EWG
MAX466CNI
MAX466CWI
MAX466C/D
MAX466ENI
MAX466EWI
MAX467CPE
MAX467CWE
MAX467C/D
MAX467EPE
MAX467EWE
MAX468CPE
MAX468CWE
MAX468C/D
MAX468EPE
MAX468EWE
MAX469CPE
MAX469CWE
MAX469C/D
MAX469EPE
MAX469EWE
MAX470CPE
MAX470CWE
MAX470C/D
MAX470EPE
MAX470EWE
+5V
MAX465
MAX466
10µF
0.1µF
ꢀ8 Narrow Plastic DIP
ꢀ8 Wide SO
A
= 2
V
IN0A
75Ω
75Ω
OUT0
OUT1
OUT2
OUT3
ꢀ4 Narrow Plastic DIP
ꢀ4 Wide SO
Dice*
IN0B
75Ω
A
A
A
= 2
= 2
= 2
V
V
V
IN1A
IN1B
ꢀ4 Narrow Plastic DIP
ꢀ4 Wide SO
ꢀ8 Narrow Plastic DIP
ꢀ8 Wide SO
Dice*
75Ω
75Ω
IN2A
IN2B
75Ω
75Ω
ꢀ8 Narrow Plastic DIP
ꢀ8 Wide SO
IN3A
IN3B
A0
16 Plastic DIP
16 Wide SO
Dice*
75Ω
LOGIC
16 Plastic DIP
16 Wide SO
16 Plastic DIP
16 Wide SO
Dice*
-5V
MAX466
ONLY
10µF
0.1µF
16 Plastic DIP
16 Wide SO
16 Plastic DIP
16 Wide SO
Dice*
16 Plastic DIP
16 Wide SO
16 Plastic DIP
16 Wide SO
Dice*
16 Plastic DIP
16 Wide SO
* Dice are specified at T = +25°C, DC parameters only.
A
16 ______________________________________________________________________________________
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