MAX465ENG-T - Maxim Integrated Products, Inc.

_______________General Description

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 ±5V supply

operation with inputs and outputs as high as ±2.5V

when driving 150Ωloads (75Ωback-terminated cable).

Input capacitance is typically only 5pF, and channel-to-

channel crosstalk is better than 60dB, accomplished by

surrounding all inputs with AC ground pins. The on-

board amplifiers feature a 200V/µs slew rate (300V/µs

for AV= 2V/V amplifiers), and a bandwidth of 100MHz

(90MHz for AV= 2V/V buffers). Channel selection is

controlled by a single TTL-compatible input pin or by a

microprocessor interface, and channel switch time is

only 20ns.

For design flexibility, devices are offered with buffer-

amplifier gains of 1V/V or 2V/V for 75Ωback-terminated

applications. Output amplifiers have a guaranteed out-

put swing of ±2V into 75Ω.

Devices offered in this series are as follows:

________________________Applications

Broadcast-Quality Color-Signal Multiplexing

RGB Multiplexing

RGB Color Video Overlay Editors

RGB Color Video Security Systems

RGB Medical Imaging

Coaxial-Cable Line Drivers

____________________________Features

♦100MHz Unity-Gain Bandwidth

♦90MHz Bandwidth with 2V/V Gain

♦0.01%/0.03° Differential Gain/Phase Error

♦Drives 50Ωand 75ΩBack-Terminated Cable Directly

♦Wide Output Swing:

±2V into 75Ω

±2.5V into 150Ω

♦300V/µs Slew Rate (2V/V gain)

♦20ns Channel Switching Time

♦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

Ordering Information continued on last page.

* Dice are specified at T

= +25°C, DC parameters only.

MAX463–MAX470

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

________________________________________________________________

Maxim Integrated Products

TOP VIEW

Pin Configurations continued at end of data sheet.

IN0A

GND

IN1A

GND

IN2A

V-

IN0B

GND

IN1B

GND

IN2B

DIP/SO

1

2

3

4

5

6

7

8

9

10

11

24

23

22

21

20

19

18

17

16

15

14

GND

LE

EN

A0

CS

V-

OUT0

V+

OUT1

GND

V+

OUT2

MAX463

MAX465

3P2T SWITCH

_________________Pin Configurations

Call toll free 1-800-998-8800 for free samples or literature.

PART TEMP. RANGE PIN-PACKAGE

MAX463CNG 0°C to +70°C 24 Narrow Plastic DIP

MAX463CWG 0°C to +70°C 24 Wide SO

MAX463C/D 0°C to +70°C Dice*

PART DESCRIPTION VOLTAGE GAIN

(V/V)

MAX463 Triple RGB Switch & Buffer 1

MAX464 Quad RGB Switch & Buffer 1

MAX465 Triple RGB Switch & Buffer 2

MAX466 Quad RGB Switch & Buffer 2

MAX467 Triple Video Buffer 1

MAX468 Quad Video Buffer 1

MAX469 Triple Video Buffer 2

MAX470 Quad Video Buffer 2

MAX463ENG 24 Narrow Plastic DIP

MAX463EWG -40°C to +85°C 24 Wide SO

-40°C to +85°C

19-0219; Rev 2; 6/94

Typical Operating Circuit appears at end of data sheet.

EVALUATION KIT MANUAL

FOLLOWS DATA SHEET

MAX463–MAX470

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

2 _______________________________________________________________________________________

Power-Supply Ranges

V+ to V- ................................................................................12V

Analog Input Voltage..........................(V- - 0.3V) to (V+ + 0.3V)

Digital Input Voltage...................................-0.3V to (V+ + 0.3V)

Output Short-Circuit Duration (to GND)........................1 Minute

Input Current into Any Pin, Power On or Off...................±50mA

Continuous Power Dissipation (TA= +70°C)

16-Pin Plastic DIP (derate 22.22mW/°C above +70°C)....1778mW

16-Pin Wide SO (derate 20.00mW/°C above +70°C) .......1600mW

24-Pin Narrow Plastic DIP

(derate 20.2mW/°C above +70°C)..................................1620mW

24-Pin Wide SO (derate 19.3mW/°C above +70°C) .........1590mW

28-Pin Narrow Plastic DIP

(derate 20.2mW/°C above +70°C)..................................1620mW

28-Pin Wide SO (derate 18.1mW/°C above +70°C) .........1440mW

Operating Temperature Ranges

MAX4_ _C_ _.........................................................0°C to +70°C

MAX4_ _E_ _......................................................-40°C to +85°C

Storage Temperature Range.............................-65°C to +150°C

Lead Temperature (soldering, 10sec).............................+300°C

ELECTRICAL CHARACTERISTICS

(V+ = 5V, V- = -5V, -2V ≤VIN ≤+2V, RLOAD = 75Ω, 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.

PARAMETER SYMBOL UNITS

Voltage-Gain Accuracy 0.2 0.5 %

Input Capacitance CIN 5 pF

On Input Resistance RIN 300 700 kΩ

On Input Bias Current IBIAS ±1 ±3 µA

0.3 1.0

Output Voltage Swing VOUT ±2.5 ±2.8 V

±2.0 ±2.4

Output Impedance ROUT

Ω

Input Voltage Range

Operating Supply Voltage VS±4.75 ±5 ±5.25 V

VIN -2 2 V

Power-Supply Rejection Ratio PSRR 50 60 dB

0.05

0.1

ROUTD 150 250 kΩ

0.7 1 kΩ

COUTD 10 pF

Positive Supply Current I+

65 80

85 100

35 45

40 50

CONDITIONS

Channel off or on

RLOAD = 150Ω

MAX463/MAX464

MAX465/MAX466

RLOAD = 75Ω

fIN = DC

MAX463–MAX466

MAX463/MAX465, disabled mode

MAX464/MAX466, disabled mode

ABSOLUTE MAXIMUM RATINGS

TA= TMIN to TMAX

MIN MAX

1.0

150 ±5

2.0

±2.5

100

-1.5/+2

0.7

100

120

±4.75 ±5.25

-2 2

Output Resistance,

Disabled Mode

Output Capacitance,

Disabled Mode

Offset Voltage VOS ±3 ±10 mV±15

MAX463/MAX464, MAX467/MAX468

(Note 1)

MAX465/MAX466, MAX469/MAX470,

RLOAD = 150Ω, (Note 2)

fIN = 10MHz

MAX463/MAX465/MAX467/MAX469,

VIN = 0V

MAX464/MAX466/MAX468/MAX470,

VIN = 0V

TA= +25°C

MIN TYP MAX

MAX463/MAX464,

MAX467/MAX468

MAX465/MAX466,

MAX469/MAX470

MAX463–MAX470

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(V+ = 5V, V- = -5V, -2V ≤VIN ≤+2V, RLOAD = 75Ω, unless otherwise noted.)

PARAMETER

Differential Phase Error

(Note 3)

SYMBOL

0.03

UNITS

deg.

300

V/µsSlew Rate

0.14

SR 200

Input Noise Density en 20 nV/√–

—

25 35

Settling Time to 0.1%

-3dB Bandwidth BW 100 MHz

tS50 ns

XTALK

0.01

Differential Gain Error

(Note 3)

DG 0.12

All-Hostile Crosstalk (Note 5) XTALK 50 dB

ISO

Negative Supply Current

I-

50 65

tPD 15 ns

65 80

tSW 20 ns

Switching Transient 300 mVP-P

20 30

tOFF 80 ns

Logic Input High Threshold VIH 2 V

Logic Input Low Threshold VIL 0.8 V

CONDITIONS

MAX463/MAX464, MAX467/MAX468

MAX465/MAX466, MAX469/MAX470

MAX463/MAX464, MAX467/MAX468

fIN = 10kHz

MAX464/MAX466, disabled mode

MAX463/MAX464, MAX467/MAX468

MAX465/MAX466, MAX469/MAX470

VIN = 2V-to-0V step

fIN = 10MHz

MAX463/MAX464, MAX467/MAX468

MAX465/MAX466, MAX469/MAX470

fIN = 10MHz

fIN = 10MHz, MAX463–MAX466

MAX463–MAX466

VINA = VINB = 0V, MAX463–MAX466

MAX463/MAX465, disabled mode

MAX463–MAX466

—

–, A0, C

—

–, LE; MAX463–MAX466

—

–, A0, C

—

–, LE; MAX463–MAX466

TA= TMIN to TMAX

MIN MAX

0.8

MAX463/MAX465/MAX467/MAX469,

VIN = 0V

MAX464/MAX466/MAX468/MAX470,

VIN = 0V

Adjacent Channel Crosstalk

(Note 4)

All-Hostile Off Isolation (Note 6)

Channel Switching

Propagation Delay (Note 7)

Logic Input Current High IINHI 200 µAE

—

–, A0, C

—

–, LE; MAX463–MAX466 200

Logic Input Current Low IINLO 200 µAE

—

–, A0, C

—

–, LE; MAX463–MAX466 200

Channel Switching Time

(Note 8)

Amplifier Switching Off-Time

(Note 9)

Amplifier Switching On-Time

(Note 10) tON 100 nsMAX463–MAX466

TA= +25°C

MIN TYP MAX

10k 100k

MAX468

GAIN AND PHASE RESPONSES

MAX463/470 -01

FREQUENCY (Hz)

GAIN (dB)

1M 100M

–3

–2

–1

180

108

144

PHASE (DEGREES)

10M

GAIN

PHASE

1G100k

MAX464

OUTPUT IMPEDANCE

vs. FREQUENCY

MAX463/470 -02

FREQUENCY (Hz)

OUTPUT IMPEDANCE ( )

1M 100M

0.01

0.1

100

10M10k

Ω

1k 100k

MAX468

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY

MAX463/470 -03

FREQUENCY (Hz)

PSRR (dB)

1M 100M

10M10k

V+

V–

MAX463–MAX470

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(V+ = 5V, V- = -5V, -2V ≤VIN ≤+2V, RLOAD = 75Ω, unless otherwise noted.)

PARAMETER SYMBOL UNITS

Address Setup Time (Note 11) tSU

CONDITIONS TA= TMIN to TMAX

MIN MAX

30 nsE

—

–, A0, C

—

–, LE; MAX463–MAX466 30

Address Hold Time (Note 11) tH0nsE

—

–, A0, C

—

–, LE; MAX463–MAX466 0

—

–Pulse Width Low (Note 11) tCS 15 nsE

—

–, A0, C

—

–, LE; MAX463–MAX466 15

Note 1: Voltage gain accuracy for the unity-gain devices is defined as [(VOUT - VIN) at VIN = 1V - (VOUT - VIN) at VIN = -1V]/2.

Note 2: Voltage gain accuracy for the gain-of-two devices is defined as [(VOUT/2 - VIN) at VIN = 1V - (VOUT/2 - VIN) at VIN = -1V]/2.

Note 3: Tested with a 3.58MHz sine wave of amplitude 40IRE superimposed on a linear ramp (0IRE to 100IRE), RL= 150Ωto ground.

Note 4: Tested with the selected input connected to ground through a 75Ωresistor, and a 4V P-P sine wave at 10MHz driving adjacent input.

Note 5: Tested in the same manner as described in Note 4, but with all other inputs driven.

Note 6: Tested with LE = 0V, E

—

–= V+, and all inputs driven with a 4VP-P, 10MHz sine wave.

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.

TA= +25°C

MIN TYP MAX

__________________________________________Typical Operating Characteristics

(TA = +25°C, unless otherwise noted.)

MAX463–MAX470

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

_______________________________________________________________________________________

100

VOLTAGE GAIN ACCURACY

vs. TEMPERATURE

MAX463/470 -04

TEMPERATURE (°C)

PERCENTAGE (%)

–25 0 5025 75–50

0.06

0.08

0.10

0.12

0.14

0.16

MAX465

MAX463

100

MAX463

DISABLED OUTPUT RESISTANCE

vs. TEMPERATURE

MAX463/470 -05

TEMPERATURE (°C)

OUTPUT RESISTANCE (kΩ)

–25 0 5025 75–50

200

250

300

350

400

100

MAX465

DISABLED OUTPUT RESISTANCE

vs. TEMPERATURE

MAX463/470 -06

TEMPERATURE (°C)

OUTPUT RESISTANCE (kΩ)

–25 0 5025 75–50

1.10

1.15

1.20

1.25

1.30

100

SUPPLY CURRENT PER AMPLIFIER

vs. TEMPERATURE

MAX463/470 -09

TEMPERATURE (°C)

SUPPLY CURRENT PER AMPLIFIER (mA)

–25 0 50

25 75

–50

I+

I–

10 100

DISABLED SUPPLY CURRENT

vs. TEMPERATURE

MAX463/470 -07

TEMPERATURE (°C)

SUPPLY CURRENT (mA)

–25 0 50

25 75

–50

I+

I–

–4 10 100

OUTPUT VOLTAGE SWING

vs. LOAD RESISTANCE

MAX463/470 -08

LOAD RESISTANCE ( )

OUTPUT VOLTAGE (V)

Ω

1000 10000

–3

–2

–1

MAX463/4/7/8:VIN = 4V

MAX465/6/9/70:VIN = 2V

____________________________Typical Operating Characteristics (continued)

(TA = +25°C, unless otherwise noted.)

MAX463–MAX470

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

6 _______________________________________________________________________________________

MAX464 

SMALL-SIGNAL STEP RESPONSE

GND

10ns/div

A: VIN,

100mV/div

B: VOUT,

100mV/div

MAX466 

SMALL-SIGNAL STEP RESPONSE

GND

10ns/div

A: VIN,

100mV/div

B: VOUT,

200mV/div

MAX464 

LARGE-SIGNAL STEP RESPONSE

GND

20ns/div

A: VIN,

2V/div

B: VOUT,

2V/div

MAX464

OUTPUT TRANSIENT WHEN SWITCHING

BETWEEN TWO GROUNDED INPUTS

50ns/div

A: CS,

5V/div

B: A0,

5V/div

C: OUT0,

100mV/div

GND

GND

GND

MAX466 

LARGE-SIGNAL STEP RESPONSE

GND

20ns/div

A: VIN,

1V/div

B: VOUT,

2V/div

MAX464 

EN RESPONSE TIME

50ns/div

A: CS,

5V/div

B: EN,

5V/div

C: OUT3,

1V/div

GND

tOFF tON

____________________________Typical Operating Characteristics (continued)

(TA = +25°C, unless otherwise noted.)

MAX463–MAX470

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

_______________________________________________________________________________________

Chip-Select—latch control for the digital inputs. When –

—

– is low, A0 and E

—

–

input registers are transparent. When C

—

– goes high, the A0 input register latches.

If LE is high, the E

—

–input register also latches when C

—

– goes high (see LE).

Digital Latch-Enable Input. When LE is low, the E

—

–register is transparent;

when LE is high, the E

—

–register is transparent only when C

—

– is low. Hard-

wire to V+ or GND for best crosstalk performance.

Channel-Select Input. When C

—

–is low, driving A0 low selects channel A

and driving A0 high selects channel B.

–

—

–

27 LE23

26 Buffer-Enable Input. When C

—

– is low or LE is low, driving E

—

–low enables

all output buffers and driving E

—

–high disables all output buffers.

25 A021

2, 4, 9,

11, 15, 24

12 Channel B, Analog Input 2IN2B12 14 Channel B, Analog Input 3IN3B– 15 Buffered Analog Output 3OUT3– 17 Buffered Analog Output 2OUT213 16, 18 Positive Power-Supply Input. Connect to +5V.V+14, 17 20 Buffered Analog Output 1OUT116 22 Buffered Analog Output 0OUT018

24 –

—

–

6 Channel A, Analog Input 3IN3A– 7, 9, 21, 23 Negative Power-Supply Input. Connect to -5V. Thermal path.V-6, 7, 19 8 Channel B, Analog Input 0IN0B8 10 Channel B, Analog Input 1IN1B10

2 Channel A, Analog Input 1IN1A3 4 Channel A, Analog Input 2IN2A5

1, 3, 5,

11, 13, 19 Analog GroundGND

MAX464/MAX466MAX463/MAX465 NAME

28 Channel A, Analog Input 0IN0A1

FUNCTION

_____________________________________________________________Pin Descriptions

14 Buffered Analog Output 1OUT114 16 Buffered Analog Output 0OUT016

10 Positive Power-Supply Input. Connect to +5V.V+10 11 Buffered Analog Output 2OUT211

MAX468/MAX470MAX467/MAX469

4, 5, 12, 13 Negative Power-Supply Input. Connect to -5V. Thermal path.V-4, 5, 12, 13 6 Analog Input 2IN26 8 Analog Input 3IN3– 9 Buffered Analog Output 3OUT3–

2, 7, 15 Analog GroundGND2, 7, 8, 9, 15 3

Analog Input 1IN13

Analog Input 0IN01

FUNCTION

PIN NAME

_______________Detailed Description

The MAX463–MAX470 have a bipolar construction,

which results in a typical channel input capacitance of

only 5pF, 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 250Ω. It also minimizes switching transients

because the driving source sees the same load

whether the channel is on or off. Low input capaci-

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.

The MAX465/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.

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.

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, V+, V-, 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 75Ωterminating resistor at

the ground plane to further reduce crosstalk (see

Figure 1).

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.

Connect all V- pins to a large power plane. The V- pins

conduct heat away from the internal die, aiding thermal

dissipation.

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.

The MAX467–MAX470 differential gain and phase errors

are measured with the Tektronix VM700 Video

Measurement Set, with the input test signal provided by

the Tektronix 1910 Digital Generator as shown in Figure 2.

Measuring the differential gain and phase of the

MAX469/MAX470 (Figure 2a) is straightforward because

the output amplifiers are configured for a gain of two,

allowing connection to the VM700 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 1/2 at the VM700.

Figure 2b 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 150Ωload 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.

MAX463–MAX470

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

8 _______________________________________________________________________________________

GROUND PLANE

RETURN

CURRENT

RETURN

CURRENT

COAX

Figure 1. Low-Crosstalk Layout. Return current from the

termination resistor does not flow through the ground plane.

MAX463–MAX470

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

_______________________________________________________________________________________ 9

Driving Coaxial Cable

High-speed performance, excellent output current

capability, and an internally fixed gain of two make the

MAX465/MAX466/MAX469/MAX470 ideal for driving

50Ωor 75Ωback-terminated coaxial cables. The

MAX465/MAX466/MAX469/MAX470 will drive a 150Ω

load (75Ωback-terminated cable) to ±2.5V.

The

Typical Operating Circuit

shows the MAX465/MAX466

driving four back-terminated 75Ωvideo 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 2V/V closed-loop gain to pro-

vide unity gain at the cable’s output.

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.

The MAX463–MAX470 phase margin and capacitive-

load driving performance are optimized by internal

compensation. When driving capacitive loads greater

than 50pF, connect an isolation resistor between the

amplifier output and the capacitive load, as shown in

Figure 3.

75Ω CABLE

75Ω

75Ω CABLE

75Ω

150Ω

SOURCE:

TEKTRONIX

1910 DIGITAL GENERATOR MEASUREMENT:

TEKTRONIX VM700

VIDEO MEASUREMENT

SET

AV = 2

MAX469/MAX470

MAX467/MAX468

DUT

(a)

(b)

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

MAX468

AV = 1

12Ω

100pF

OUT_IN_



Figure 3a. Using an Isolation Resistor with a Capacitive Load

MAX463–MAX470

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

10 ______________________________________________________________________________________

tCS

tSU tH

tSU

tOFF HIGH-Z

tON

tPD tSW

OUTPUTS

LE = V+

Figure 4. Logic Timing Diagram

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 C

—

–low (see Tables 1a, 1b).

Figure 4 shows the logic timing diagram.

Output Disable (MAX463–MAX466)

When the enable input (E

—

–) is driven to a TTL low state, it

enables the MAX463–MAX466 amplifier outputs. When E

—

–

is driven high, it disables the amplifier outputs. The

disabled MAX463/MAX464 outputs exhibit a 250kΩ

typical resistance. Because their internal feedback

resistors are required to produce a gain of two, the

MAX465/MAX466 exhibit a 1kΩdisabled output resis-

tance.

LE determines whether E

—

–is latched by C

—

–or operates

independently. When the latch-enable input (LE) is con-

nected to V+, C

—

–becomes the latch control for the E

—

–

input register. If C

—

– is low, both the E

—

–and A0 registers

are transparent; once C

—

– returns high, both registers

are latched.

MAX468 (NO ISOLATION RESISTOR)

GND

1µs/div

CLOAD = 100pF

A: VIN, 500mV/div

B: VOUT, 500mV/div

Figure 3b. Step Response without an Isolation Resistor

MAX468 (WITH ISOLATION RESISTOR)

GND

1µs/div

CLOAD = 100pF, RISOLATION = 12Ω

A: VIN, 500mV/div

B: VOUT, 500mV/div

Figure 3c. Step Response with an Isolation Resistor

MAX463–MAX470

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

______________________________________________________________________________________ 11

When LE is connected to ground, the E

—

–register is

transparent and independent of C

—

–activity. This allows

all MAX463–MAX466 devices to be simultaneously shut

down, regardless of the C

—

–input state. Simply connect

LE to ground and connect all E

—

–inputs together (Figure

5a). For the MAX464 and MAX466, LE must be hard-

wired to either V+ or ground (rather than driving LE with

a gate) to prevent crosstalk from the digital inputs to

IN0A.

Another option for output disable is to connect LE to V+,

parallel the outputs of several MAX463-MAX466s, and use

—

–to individually disable all devices but the one in use

(Figure 5b).

When the outputs are disabled, the off isolation from

the analog inputs to the amplifier outputs is typically

70dB at 10MHz, all inputs driven with a 4VP-P sine

wave and a 150Ωload impedance. Figure 6 shows the

test circuits used to measure isolation and crosstalk.

Table 1a. Amplifier and Channel Selection

with LE = V+ Table 1b. Amplifier and Channel Selection

with LE = GND

Disables amplifiers. Outputs high-Z.

A0 register = channel B

110

Disables amplifiers. Outputs high-Z.X11

Enables amplifier outputs, latches A0

or B, according to the setting of A0 at

—

–'s last edge.

X01

Disables amplifiers. Outputs high-Z.

A0 register = channel A

010

Enables amplifier outputs.

Selects channel B.

100

Enables amplifier outputs.

Selects channel A.

000

FUNCTIONA0E

—

–

—

–

Latches all input registers.

Changes nothing.

Enables amplifier outputs.

Selects channel B.

Enables amplifier outputs.

Selects channel A.

XX1

Disables amplifiers. Outputs high-Z.X10

100

000

FUNCTIONA0E

—

–

—

–

MAX463–

MAX466 MAX463–

MAX466

MAX463–

MAX466

MAX463–

MAX466

SHUTDOWN

+5V



(a) (b)

Figure 5. (a) Simultaneous Shutdown of all MAX463–MAX466, (b) Enable (–

—

–) Register Latched by –

—

–

NOTE: ISOLATION RESISTORS,

IF REQUIRED, NOT SHOWN.

MAX463–MAX470

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

12 ______________________________________________________________________________________



MAX463–MAX466 

MAX463–MAX466

VIN = 4VP-P AT 10MHz,

RS = 75Ω

MAX467–MAX470 

MAX467–MAX470

VIN = 4VP-P

AT 10MHz,

RS = 75Ω

150Ω

75Ω

VIN = 4VP-P AT 10MHz,

RS = 75Ω

VIN = 4VP-P 

AT 10MHz,

RS = 75Ω

150Ω

75Ω

150Ω

75Ω

(a) (b)

150Ω

+5V

ENLE

150Ω

* 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

Figure 7. Higher-Order RGB + Sync Video Multiplexer

MAX463–MAX470

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

______________________________________________________________________________________ 13

MAX464

–5V

4P2T VIDEO SWITCH

75Ω

–5V

+5V

–5V

+5V

GND

IN3B

GND

IN2B

V–

IN1B

V–

IN0B

GND

IN3A

GND

IN2A

GND

IN1A

V–

IN0A

OUT0

V–

OUT1

GND

V+

OUT2

V+

OUT3

75Ω75Ω

MAX464

–5V

4P2T VIDEO SWITCH

75Ω

–5V

+5V

–5V

+5V

GND

IN3B

GND

IN2B

V–

IN1B

V–

IN0B

GND

IN3A

GND

IN2A

GND

IN1A

V–

IN0A

OUT0

V–

OUT1

GND

V+

OUT2

V+

OUT3

75Ω75Ω

MAX470

OUT0

OUT1

OUT2

OUT3

IN0

IN1

IN2

IN3

–5V

V+

V–

V+

GNDGND

GND

75Ω

FROM OTHER

MAX464s

MAX463–MAX470

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

14 ______________________________________________________________________________________

MAX466

–5V

QUAD SPDT VIDEO SWITCH

75Ω

–5V

+5V

–5V

+5V

GND

IN3B

GND

IN2B

V–

IN1B

V–

IN0B

GND

IN3A

GND

IN2A

GND

IN1A

V–

IN0A

OUT0

V–

OUT1

GND

V+

OUT2

V+

OUT3

50Ω75Ω

MAX466

–5V

QUAD SPDT VIDEO SWITCH

75Ω

–5V

+5V

–5V

+5V

GND

IN3B

GND

IN2B

V–

IN1B

V–

IN0B

GND

IN3A

GND

IN2A

GND

IN1A

V–

IN0A

OUT0

V–

OUT1

GND

V+

OUT2

V+

OUT3

50Ω75Ω

22Ω

A1 A0 CS

Figure 8. 1-of-4 RGB + Sync Video Multiplexer

MAX463–MAX470

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

______________________________________________________________________________________ 15

__________Applications Information

Higher-Order RGB + Sync

Video Multiplexing

Higher-order RGB video multiplexers can be realized

by paralleling several MAX463/MAX464s. Connect LE

to V+ and use C

—

– and E

—

–to disable all devices but the

one in use. Since the disabled output resistance of the

MAX463/MAX464 is 250kΩ, 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).

Paralleling MAX466s to Switch

1-of-4 RGB + Sync Signal Inputs

Figure 8 shows a 1-of-4 RGB + sync video mux/amp

circuit. The 1kΩdisabled output resistance limits the

number of paralleled MAX465/MAX466s to no more

than two. The amplifier outputs are connected after a

22Ωisolation resistor and ahead of a 50Ωback-termi-

nation resistor, which isolates the active amplifier out-

put from the capacitive load (5pF 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.

28

27

26

25

24

23

22

21

20

19

18

17

16

TOP VIEW

GND

IN1A

GND

IN2A

GND

IN3A

V-

IN0B

V-

IN1B

GND

IN2B

GND

IN3B

DIP/SO

1

2

3

4

5

6

7

8

9

10

11

12

13

IN0A

LE

EN

A0

CS

V-

OUT0

V-

OUT1

GND

V+

OUT2

V+

OUT3

MAX464

MAX466

4P2T SWITCH

IN0

GND

IN1

V-

IN2

GND

IN3

DIP/SO

1

2

3

4

5

6

7

16

15

14

13

12

11

10

OUT0

GND

OUT1

V-

OUT2

V+

OUT3

MAX468

MAX470

QUAD

BUFFERS

IN0

GND

IN1

V-

IN2

GND

GND

DIP/SO

MAX467

MAX469

TRIPLE (RGB)

BUFFERS

1

2

3

4

5

6

7

16

15

14

13

12

11

10

OUT0

GND

OUT1

V-

OUT2

V+

GND

_____________________________________________Pin Configurations (continued)

MAX463–MAX470

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

16 ______________________________________________________________________________________

IN0A

IN0B

MAX465

MAX466

OUT0

LOGIC

MAX466

ONLY

IN1A

IN1B OUT1

IN2A

IN2B OUT2

IN3A

IN3B OUT3

10µF 0.1µF

-5V

75Ω

10µF 0.1µF

+5V

AV = 2

__________Typical Operating Circuit _Ordering Information (continued)

* Dice are specified at T

= +25°C, DC parameters only.

PART TEMP. RANGE PIN-PACKAGE

MAX464CNI 0°C to +70°C 28 Narrow Plastic DIP

MAX464CWI 0°C to +70°C 28 Wide SO

MAX464C/D 0°C to +70°C Dice*

MAX464ENI -40°C to +85°C 28 Narrow Plastic DIP

MAX465CNG 0°C to +70°C 24 Narrow Plastic DIP

MAX465CWG 0°C to +70°C 24 Wide SO

MAX465C/D 0°C to +70°C Dice*

MAX465ENG -40°C to +85°C 24 Narrow Plastic DIP

MAX465EWG -40°C to +85°C 24 Wide SO

MAX467EWE -40°C to +85°C 16 Wide SO

MAX467EPE -40°C to +85°C 16 Plastic DIP

MAX467C/D 0°C to +70°C Dice*

MAX467CWE 0°C to +70°C 16 Wide SO

MAX467CPE 0°C to +70°C 16 Plastic DIP

MAX466ENI -40°C to +85°C 28 Narrow Plastic DIP

MAX466C/D 0°C to +70°C Dice*

MAX466CWI 0°C to +70°C 28 Wide SO

MAX466CNI 0°C to +70°C 28 Narrow Plastic DIP

MAX470EPE -40°C to +85°C 16 Plastic DIP

MAX470C/D 0°C to +70°C Dice*

MAX470CWE 0°C to +70°C 16 Wide SO

MAX470CPE 0°C to +70°C 16 Plastic DIP

MAX469EWE -40°C to +85°C 16 Wide SO

MAX469EPE -40°C to +85°C 16 Plastic DIP

MAX469C/D 0°C to +70°C Dice*

MAX469CWE 0°C to +70°C 16 Wide SO

MAX469CPE 0°C to +70°C 16 Plastic DIP

MAX468EPE -40°C to +85°C 16 Plastic DIP

MAX468C/D 0°C to +70°C Dice*

MAX468CWE 0°C to +70°C 16 Wide SO

MAX468CPE 0°C to +70°C 16 Plastic DIP

MAX464EWI -40°C to +85°C 28 Wide SO

MAX466EWI -40°C to +85°C 28 Wide SO

MAX468EWE -40°C to +85°C 16 Wide SO

MAX470EWE -40°C to +85°C 16 Wide SO