Maxim MAX469CWE, MAX469CPE, MAX469C-D, MAX468EWE, MAX468CWE Datasheet

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19-0219; Rev 2; 6/94

EVALUATION KIT MANUAL

FOLLOWS DATA SHEET

RGB Video Switches and Buffers

_______________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 applications. The devices are all specified for ±5V supply operation with inputs and outputs as high as ±2.5V when driving 150Ω loads (75Ω back-terminated cable).

Input capacitance is typically only 5pF, and channel-tochannel crosstalk is better than 60dB, accomplished by surrounding all inputs with AC ground pins. The onboard 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 bufferamplifier gains of 1V/V or 2V/V for 75Ω back-terminated applications. Output amplifiers have a guaranteed output swing of ±2V into 75Ω.

Devices offered in this series are as follows:

PART DESCRIPTION

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

VOLTAGE GAIN

(V/V)

________________________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

Two-Channel, Triple/Quad

____________________________Features

♦ 100MHz Unity-Gain Bandwidth ♦ 90MHz Bandwidth with 2V/V Gain ♦ 0.01%/0.03° Differential Gain/Phase Error ♦ Drives 50Ω and 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

PART TEMP. RANGE PIN-PACKAGE

MAX463CNG

MAX463CWG 0°C to +70°C 24 Wide SO MAX463C/D 0°C to +70°C Dice* MAX463ENG 24 Narrow Plastic DIP MAX463EWG -40°C to +85°C 24 Wide SO

Ordering Information continued on last page.

* Dice are specified at T

_________________Pin Configurations

TOP VIEW

IN0A

IN1A

IN2A

IN0B

IN1B

IN2B

0°C to +70°C 24 Narrow Plastic DIP

-40°C to +85°C

= +25°C, DC parameters only.

1

GND

2 3 4 5

V-

6

V-

7 8

9 10 11 12

MAX463 MAX465

3P2T SWITCH

24

GND

23

LE

22

EN

21

A0

20

CS

19

V-

18

OUT0

17

V+

16

OUT1

15

GND

14

V+

OUT2

MAX463–MAX470

Typical Operating Circuit appears at end of data sheet.

________________________________________________________________

Pin Configurations continued at end of data sheet.

DIP/SO

Maxim Integrated Products

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

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 (T

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

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

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.

= +70°C)

ELECTRICAL CHARACTERISTICS

(V+ = 5V, V- = -5V, -2V ≤ VIN≤ +2V, R

MAX463–MAX470

PARAMETER SYMBOL UNITS

Operating Supply Voltage V Input Voltage Range Offset Voltage V Power-Supply Rejection Ratio PSRR 50 60 dB

On Input Bias Current I On Input Resistance R Input Capacitance C

Voltage-Gain Accuracy

Output Voltage Swing V

Output Impedance R

Output Resistance, Disabled Mode

Output Capacitance, Disabled Mode

Positive Supply Current I+

= 75Ω, unless otherwise noted.)

LOAD

CONDITIONS

BIAS

Channel off or on

MAX463/MAX464, MAX467/MAX468 (Note 1)

MAX465/MAX466, MAX469/MAX470, R

= 150Ω, (Note 2)

LOAD

= 150Ω

OUT

OUTD

LOAD

= 75Ω

LOAD

fIN= 10MHz

fIN= DC

MAX463/MAX464 MAX465/MAX466

MAX463–MAX466 MAX463/MAX465/MAX467/MAX469,

VIN= 0V MAX464/MAX466/MAX468/MAX470,

VIN= 0V MAX463/MAX465, disabled mode MAX464/MAX466, disabled mode

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

MAX463/MAX464, MAX467/MAX468

MAX465/MAX466, MAX469/MAX470

TA= +25°C

MIN TYP MAX

±4.75 ±5 ±5.25 V

-2 2 V ±3 ±10 mV±15

±1 ±3 µA

300 700 kΩ

5 pF

0.2 0.5

0.3 1.0

±2.5 ±2.8 ±2.0 ±2.4

0.05

0.1

150 250 kΩ

0.7 1 kΩ 10 pF

65 80

85 100 35 45

40 50

TA= T

to T

MIN

MIN MAX

±4.75 ±5.25

-2 2

150

±2.5

-1.5/+2

100

0.7

MAX

±5

1.0

2.0

100

120

50 55

Ω

2 _______________________________________________________________________________________

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

ELECTRICAL CHARACTERISTICS (continued)

(V+ = 5V, V- = -5V, -2V ≤ VIN≤ +2V, R

PARAMETER

Negative Supply Current

Input Noise Density en 20 nV/√–H—z

-3dB Bandwidth BW

Differential Gain Error (Note 3)

Differential Phase Error (Note 3)

Settling Time to 0.1% Adjacent Channel Crosstalk

(Note 4) All-Hostile Crosstalk (Note 5) XTALK 50 dB

All-Hostile Off Isolation (Note 6) Channel Switching

Propagation Delay (Note 7) Channel Switching Time

(Note 8) Switching Transient 300 mV Amplifier Switching Off-Time

(Note 9) Amplifier Switching On-Time

(Note 10) Logic Input High Threshold V Logic Input Low Threshold V Logic Input Current High I Logic Input Current Low I

SYMBOL

XTALK

= 75Ω, unless otherwise noted.)

LOAD

CONDITIONS

MAX463/MAX465/MAX467/MAX469, VIN= 0V

MAX464/MAX466/MAX468/MAX470,

I-

VIN= 0V MAX463/MAX465, disabled mode MAX464/MAX466, disabled mode fIN= 10kHz MAX463/MAX464, MAX467/MAX468

MAX465/MAX466, MAX469/MAX470 MAX463/MAX464, MAX467/MAX468 MAX465/MAX466, MAX469/MAX470 MAX463/MAX464, MAX467/MAX468

MAX465/MAX466, MAX469/MAX470 MAX463/MAX464, MAX467/MAX468

MAX465/MAX466, MAX469/MAX470

VIN= 2V-to-0V step

fIN= 10MHz fIN= 10MHz

ISO

fIN= 10MHz, MAX463–MAX466

MAX463–MAX466

= V

INA

MAX463–MAX466

OFF

E—N–, A0, C—S–, LE; MAX463–MAX466

INHI

INLO

= 0V, MAX463–MAX466

INB

TA= +25°C

MIN TYP MAX

50 65

65 80 20 30

25 35

200 300 100

0.01

0.12

0.03

0.14 50 ns

70 15 ns

20 ns

80 ns

100 nsMAX463–MAX466

0.8 V

TA= T

2 V

200 µAE—N–, A0, C—S–, LE; MAX463–MAX466 200 200 µAE—N–, A0, C—S–, LE; MAX463–MAX466 200

to T

MIN

MIN MAX

35 40

0.8

MAX

UNITS

V/µsSlew Rate

MHz

deg.

MAX463–MAX470

P-P

_______________________________________________________________________________________ 3

Two-Channel, Triple/Quad RGB Video Switches and Buffers

ELECTRICAL CHARACTERISTICS (continued)

(V+ = 5V, V- = -5V, -2V ≤ VIN≤ +2V, R

PARAMETER

SYMBOL UNITS

Address Setup Time (Note 11) t Address Hold Time (Note 11) t C—S–Pulse Width Low (Note 11) t

Note 1: Voltage gain accuracy for the unity-gain devices is defined as [(V Note 2: Voltage gain accuracy for the gain-of-two devices is defined as [(V Note 3: Tested with a 3.58MHz sine wave of amplitude 40IRE superimposed on a linear ramp (0IRE to 100IRE), R Note 4: Tested with the selected input connected to ground through a 75Ω resistor, and a 4V 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—N–= V+, and all inputs driven with a 4V 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.

MAX463–MAX470

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

(TA = +25°C, unless otherwise noted.)

= 75Ω, unless otherwise noted.)

LOAD

CONDITIONS

MIN TYP MAX

30 nsE—N–, A0, C—S–, LE; MAX463–MAX466 30

15 nsE—N–, A0, C—S–, LE; MAX463–MAX466 15

- VIN) at VIN= 1V - (V

OUT

/2 - VIN) at VIN= 1V - (V

OUT

, 10MHz sine wave.

P-P

= +25°C

TA= T

to T

MIN

MIN MAX

MAX

0 nsE—N–, A0, C—S–, LE; MAX463–MAX466 0

- VIN) at VIN= -1V]/2.

OUT

/2 - VIN) at VIN= -1V]/2.

OUT

= 150Ω to ground.

sine wave at 10MHz driving adjacent input.

P-P

GAIN AND PHASE RESPONSES

GAIN (dB)

–1

–2

–3

10k 100k

FREQUENCY (Hz)

MAX468

GAIN

PHASE

1M 100M

10M

MAX463/470 -01

0 36 72 108 144

PHASE (DEGREES)

180

OUTPUT IMPEDANCE

100

Ω

OUTPUT IMPEDANCE ( )

0.1

0.01

vs. FREQUENCY

FREQUENCY (Hz)

MAX464

1M 100M

10M10k

MAX463/470 -02

1G100k

POWER-SUPPLY REJECTION RATIO

PSRR (dB)

1k 100k

vs. FREQUENCY

FREQUENCY (Hz)

4 _______________________________________________________________________________________

MAX468

1M 100M

MAX463/470 -03

V–

V+

10M10k

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

____________________________Typical Operating Characteristics (continued)

(TA = +25°C, unless otherwise noted.)

VOLTAGE GAIN ACCURACY

0.16

0.14

0.12

0.10

PERCENTAGE (%)

0.08

0.06

SUPPLY CURRENT PER AMPLIFIER (mA)

–50

vs. TEMPERATURE

MAX465

MAX463

–25 0 5025 75–50

TEMPERATURE (°C)

SUPPLY CURRENT PER AMPLIFIER

vs. TEMPERATURE

I+

I–

–25 0 50

25 75

TEMPERATURE (°C)

MAX463/470 -04

100

MAX463/470 -09

100

DISABLED OUTPUT RESISTANCE

vs. TEMPERATURE

400

350

300

250

OUTPUT RESISTANCE (kΩ)

200

–25 0 5025 75–50

TEMPERATURE (°C)

DISABLED SUPPLY CURRENT

SUPPLY CURRENT (mA)

–50

vs. TEMPERATURE

I+

I–

–25 0 50

TEMPERATURE (°C)

MAX463

25 75

MAX463/470 -05

100

MAX463/470 -07

100

DISABLED OUTPUT RESISTANCE

1.30

1.25

1.20

1.15

OUTPUT RESISTANCE (kΩ)

1.10

4 3 2 1 0

–1

OUTPUT VOLTAGE (V)

–2 –3 –4

10 100

MAX465

vs. TEMPERATURE

–25 0 5025 75–50

TEMPERATURE (°C)

OUTPUT VOLTAGE SWING

vs. LOAD RESISTANCE

MAX463/4/7/8:VIN = 4V MAX465/6/9/70:V

LOAD RESISTANCE ( )

1000 10000

= 2V

Ω

MAX463–MAX470

MAX463/470 -06

100

MAX463/470 -08

_______________________________________________________________________________________

Two-Channel, Triple/Quad RGB Video Switches and Buffers

____________________________Typical Operating Characteristics (continued)

(TA = +25°C, unless otherwise noted.)

SMALL-SIGNAL STEP RESPONSE

MAX464 

GND

MAX463–MAX470

10ns/div

MAX464 

LARGE-SIGNAL STEP RESPONSE

GND

20ns/div

,

A: V

100mV/div   B: V

OUT

100mV/div

A: VIN, 2V/div   B: V

OUT

2V/div

SMALL-SIGNAL STEP RESPONSE

MAX466 

,

A: V

GND

,

GND

10ns/div

100mV/div   B: V

OUT

200mV/div

,

MAX466 

LARGE-SIGNAL STEP RESPONSE

GND

,

20ns/div

A: V 1V/div   B: V 2V/div

,

OUT

OUTPUT TRANSIENT WHEN SWITCHING

BETWEEN TWO GROUNDED INPUTS

GND

GND



GND

50ns/div

A: CS, 5V/div  B: A0, 5V/div  C: OUT0, 100mV/div

GND

OFF

MAX464 

EN RESPONSE TIME

6 _______________________________________________________________________________________

MAX464

A: CS, 5V/div  B: EN, 5V/div  C: OUT3, 1V/div

50ns/div

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

_____________________________________________________________Pin Descriptions

2, 4, 9,

11, 15, 24

MAX464/MAX466MAX463/MAX465

28 Channel A, Analog Input 0IN0A1

1, 3, 5,

11, 13, 19

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

25 A021

27 LE23

NAME

–C—S–

–E—N–

FUNCTION

Analog GroundGND

Chip-Select—latch control for the digital inputs. When –C—S– is low, A0 and E—N input registers are transparent. When C—S– goes high, the A0 input register latches. If LE is high, the E—N–input register also latches when C—S– goes high (see LE).

Channel-Select Input. When C—S–is low, driving A0 low selects channel A and driving A0 high selects channel B.

Buffer-Enable Input. When C—S– is low or LE is low, driving E—N–low enables all output buffers and driving E—N–high disables all output buffers.

Digital Latch-Enable Input. When LE is low, the E—N–register is transparent; when LE is high, the E—N–register is transparent only when C—S– is low. Hardwire to V+ or GND for best crosstalk performance.

–

MAX463–MAX470

MAX468/MAX470MAX467/MAX469

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

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– 10 Positive Power-Supply Input. Connect to +5V.V+10 11 Buffered Analog Output 2OUT211 14 Buffered Analog Output 1OUT114 16 Buffered Analog Output 0OUT016

_______________________________________________________________________________________

NAME

Analog Input 0IN01

Analog Input 1IN13

FUNCTION

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 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 capacitance is critical, because it forms a single-pole RC lowpass 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 overall gain of one at the cable output when driving back-ter-

MAX463–MAX470

minated coaxial cable (see the section

Cable

). The MAX463/MAX464/MAX467/MAX468 are

internally configured for unity gain.

Driving Coaxial

Power-Supply Bypassing and Board Layout

To realize the full AC performance of high-speed amplifiers, 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 dedicated 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 75Ω terminating 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 aluminum-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.

COAX

Figure 1. Low-Crosstalk Layout. Return current from the termination resistor does not flow through the ground plane.

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 are critical specifications 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 broadcastquality 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-terminated 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 differential 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 150Ω 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.

RETURN

CURRENT

GROUND PLANE

RETURN

CURRENT

Differential Gain and Phase Errors

8 _______________________________________________________________________________________

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

(a)

75Ω

SOURCE: TEKTRONIX 1910 DIGITAL GENERATOR

75Ω CABLE

(b)

75Ω

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

75Ω CABLE

MAX469/MAX470

DUT

MAX467/MAX468

DUT

150Ω

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 50Ω or 75Ω back-terminated coaxial cables. The MAX465/MAX466/MAX469/MAX470 will drive a 150Ω

75Ω CABLE

75Ω

75Ω CABLE

75Ω

AV = 2

75Ω

MEASUREMENT: TEKTRONIX VM700 VIDEO MEASUREMENT SET

75Ω CABLE

75Ω

The MAX463–MAX470 phase margin and capacitiveload 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.

load (75Ω back-terminated cable) to ±2.5V. The

Typical Operating Circuit

shows the MAX465/MAX466 driving four back-terminated 75Ω video cables. The back-termination resistor (at each amplifier output) provides 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 provide unity gain at the cable’s output.

AV = 1

12Ω

OUT_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 followers. The amplifier’s output impedance and the capaci-



MAX468

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.

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

MAX463–MAX470

100pF

_______________________________________________________________________________________ 9

Two-Channel, Triple/Quad RGB Video Switches and Buffers

MAX468 (NO ISOLATION RESISTOR)

GND

= 100pF

LOAD

, 500mV/div

A: V

MAX463–MAX470

B: V

, 500mV/div

OUT

1µs/div

Figure 3b. Step Response without an Isolation Resistor

Digital Interface

The MAX463–MAX466 multiplexer architecture provides an input transistor buffer, ensuring that no input channels 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—S–low (see Tables 1a, 1b). Figure 4 shows the logic timing diagram.

Output Disable (MAX463–MAX466)

When the enable input (E—N–) is driven to a TTL low state, it enables the MAX463–MAX466 amplifier outputs. When E—N is driven high, it disables the amplifier outputs. The

MAX468 (WITH ISOLATION RESISTOR)

GND

C A: V B: V

LOAD

= 100pF, R

, 500mV/div

, 500mV/div

OUT

ISOLATION

1µs/div

= 12Ω

Figure 3c. Step Response with an Isolation Resistor

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 1kΩ disabled output resistance.

LE determines whether E—N–is latched by C—S–or operates independently. When the latch-enable input (LE) is connected to V+, C—S–becomes the latch control for the E—N input register. If C—S– is low, both the E—N–and A0 registers

–

are transparent; once C—S– returns high, both registers

–

are latched.

OUTPUTS

LE = V+

OFF

HIGH-Z

Figure 4. Logic Timing Diagram

10 ______________________________________________________________________________________

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

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

–

C—S

Enables amplifier outputs.

000

Selects channel A. Enables amplifier outputs.

100

Selects channel B. Disables amplifiers. Outputs high-Z.X10 Latches all input registers.

XX1

Changes nothing.

When LE is connected to ground, the E—N–register is transparent and independent of C—S–activity. This allows all MAX463–MAX466 devices to be simultaneously shut down, regardless of the C—S–input state. Simply connect LE to ground and connect all E—N–inputs together (Figure 5a). For the MAX464 and MAX466, LE must be hardwired to either V+ or ground (rather than driving LE with a gate) to prevent crosstalk from the digital inputs to IN0A.

FUNCTIONA0E—N

Table 1b. Amplifier and Channel Selection with LE = GND

–

C—S

Enables amplifier outputs.

000

Selects channel A. Enables amplifier outputs.

100

Selects channel B. Disables amplifiers. Outputs high-Z.

010

A0 register = channel A Disables amplifiers. Outputs high-Z.

110

A0 register = channel B Enables amplifier outputs, latches A0

X01

or B, according to the setting of A0 at C—S–'s last edge.

Disables amplifiers. Outputs high-Z.X11

Another option for output disable is to connect LE to V+, parallel the outputs of several MAX463-MAX466s, and use E—N–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 4V wave and a 150Ω load impedance. Figure 6 shows the test circuits used to measure isolation and crosstalk.

FUNCTIONA0E—N

sine

P-P

MAX463–MAX470

+5V



EN AO CS

MAX463–

MAX466

MAX463–

MAX466

(b)

MAX463–

MAX466

SHUTDOWN

NOTE: ISOLATION RESISTORS,

IF REQUIRED, NOT SHOWN.

Figure 5. (a) Simultaneous Shutdown of all MAX463–MAX466, (b) Enable (–E—N–) Register Latched by –C—S

______________________________________________________________________________________ 11

MAX463–

MAX466

(a)

–

Two-Channel, Triple/Quad RGB Video Switches and Buffers

MAX467–MAX470

75Ω

VIN = 4V



P-P

AT 10MHz,

= 75Ω

MAX463–MAX470

(a) (b)



MAX463–MAX466

150Ω

75Ω

VIN = 4V AT 10MHz,

= 75Ω

MAX467–MAX470



P-P

MAX463–MAX466



150Ω



150Ω

VIN = 4V

= 75Ω

150Ω

ENLE

AT 10MHz,

P-P

+5V

* MAX464/MAX466/MAX468/MAX470 ONLY

VIN = 4V R

= 75Ω

AT 10MHz,

P-P

150Ω

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

MAX463–MAX470

75Ω

GND

IN1A

GND

IN2A

GND

IN3A

V–

–5V

IN0B

V–

–5V

IN1B

GND

IN2B

GND

IN3B

GND

IN1A

GND

IN2A

GND

IN3A

V–

–5V

IN0B

V–

–5V

IN1B

GND

IN2B

GND

IN3B

MAX464

4P2T VIDEO SWITCH

MAX464

4P2T VIDEO SWITCH

IN0A

OUT0

OUT1

GND

OUT2

OUT3

IN0A

OUT0

OUT1

GND

OUT2

OUT3

+5V

–5V

V–

75Ω

–5V

V–

75Ω

+5V

V+

75Ω

+5V

V+

75Ω

28 27

+5V

–5V

V–

75Ω

–5V

V–

75Ω

+5V

V+

75Ω

+5V

V+

75Ω

FROM OTHER

MAX464s

–5V

IN0

IN1

IN2

GND

IN3

MAX470

OUT0

75Ω

GNDGND

OUT1

75Ω

OUT2

OUT3

V–

–5V

V–

–5V

75Ω

V+

75Ω

V– V–

75Ω

Figure 7. Higher-Order RGB + Sync Video Multiplexer

______________________________________________________________________________________ 13

Two-Channel, Triple/Quad RGB Video Switches and Buffers

75Ω

GND

IN1A

75Ω

GND

IN2A

75Ω

GND

IN3A

75Ω

V–

–5V

IN0B

75Ω

MAX463–MAX470

75Ω

V–

–5V

13 14

IN1B

GND IN2B

GND IN3B

GND IN1A

GND IN2A

GND IN3A

V– IN0B

V– IN1B

GND IN2B

GND IN3B

QUAD SPDT VIDEO SWITCH

MAX466

IN0A

OUT0

OUT1

GND

OUT2

OUT3

IN0A

OUT0

OUT1

GND

OUT2

OUT3

+5V

–5V

22Ω

–5V

22Ω

+5V

22Ω

+5V

22Ω

+5V

–5V

22Ω

–5V

22Ω

+5V

22Ω

+5V

22Ω

A1 A0 CS

50Ω

75Ω

28 27

V–

20 19

V+

28 27

V–

20 19

V+

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

14 ______________________________________________________________________________________

Two-Channel, Triple/Quad

RGB Video Switches and Buffers

__________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—S– and E—N–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).

Figure 8 shows a 1-of-4 RGB + sync video mux/amp circuit. The 1kΩ disabled output resistance limits the number of paralleled MAX465/MAX466s to no more than two. The amplifier outputs are connected after a 22Ω isolation resistor and ahead of a 50Ω back-termination resistor, which isolates the active amplifier output 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 output signals. For multiplexing more than two devices, see the section

Multiplexing,

Paralleling MAX466s to Switch

1-of-4 RGB + Sync Signal Inputs

Higher Order RGB + Sync Video

above.

_____________________________________________Pin Configurations (continued)

TOP VIEW

GND IN1A GND IN2A GND IN3A

IN0B

IN1B GND IN2B GND IN3B

1 2 3 4 5 6

V-

7 8

V-

9 10 11 12 13 14

MAX464

MAX466

4P2T SWITCH

28

IN0A

27

LE

26

EN

25

A0

24

CS

23

V-

22

OUT0

21

V-

20

OUT1

19

GND

18

V+

17

OUT2

16

V+

OUT3

IN0

GND

IN1

V- V-

IN2 GND GND

1 2 3 4 5 6 7 8

DIP/SO

MAX467 MAX469

TRIPLE (RGB)

BUFFERS

16

OUT0

15

GND

14

OUT1

13

V-

12

V-

11

OUT2

10

V+

GND

IN0

GND

IN1

IN2

GND

IN3

1 2 3

V-

4

V-

5 6 7 8

16

OUT0

15

GND

14

OUT1

13

V-

12

V-

11

OUT2

10

V+

OUT3

DIP/SO

MAX468 MAX470

QUAD

BUFFERS

MAX463–MAX470

DIP/SO

______________________________________________________________________________________ 15

Two-Channel, Triple/Quad RGB Video Switches and Buffers

__________Typical Operating Circuit _Ordering Information (continued)

PART TEMP. RANGE PIN-PACKAGE

+5V

AV = 2

= 2

0.1µF

MAX465 MAX466

OUT0

OUT1

OUT2

OUT3

75Ω

MAX466

ONLY

10µF

IN0A

IN0B

IN1A

IN1B

MAX463–MAX470

IN2A

IN2B

IN3A

IN3B

-5V

0.1µF

LOGIC

10µF

75Ω

MAX464CNI 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 MAX464EWI -40°C to +85°C 28 Wide SO MAX465CNG 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 MAX466CNI MAX466CWI 0°C to +70°C 28 Wide SO MAX466C/D 0°C to +70°C Dice* MAX466ENI -40°C to +85°C 28 Narrow Plastic DIP MAX466EWI -40°C to +85°C 28 Wide SO MAX467CPE MAX467CWE 0°C to +70°C 16 Wide SO MAX467C/D 0°C to +70°C Dice* MAX467EPE -40°C to +85°C 16 Plastic DIP MAX467EWE -40°C to +85°C 16 Wide SO MAX468CPE MAX468CWE 0°C to +70°C 16 Wide SO MAX468C/D 0°C to +70°C Dice* MAX468EPE -40°C to +85°C 16 Plastic DIP MAX468EWE -40°C to +85°C 16 Wide SO MAX469CPE MAX469CWE 0°C to +70°C 16 Wide SO MAX469C/D 0°C to +70°C Dice* MAX469EPE -40°C to +85°C 16 Plastic DIP MAX469EWE -40°C to +85°C 16 Wide SO MAX470CPE MAX470CWE 0°C to +70°C 16 Wide SO MAX470C/D 0°C to +70°C Dice* MAX470EPE -40°C to +85°C 16 Plastic DIP MAX470EWE -40°C to +85°C 16 Wide SO

* Dice are specified at TA= +25°C, DC parameters only.

0°C to +70°C 28 Narrow Plastic DIP

0°C to +70°C 24 Narrow Plastic DIP

0°C to +70°C 28 Narrow Plastic DIP

0°C to +70°C 16 Plastic DIP

16 ______________________________________________________________________________________

Maxim MAX469CWE, MAX469CPE, MAX469C-D, MAX468EWE, MAX468CWE Datasheet

Specifications and Main Features

Frequently Asked Questions

User Manual