MAXIM MAX456 Technical data

查询MAX456供应商

19-2858; Rev 2; 2/94

8 x 8 Video Crosspoint Switch

_______________General Description

The MAX456 is the first monolithic CMOS 8 x 8 video crosspoint switch that significantly reduces component count, board space, and cost. The crosspoint switch contains a digitally controlled matrix of 64 T-switches that connect eight video input signals to any, or all, output channels. Each matrix output connects to eight internal, high-speed (250V/µs), unity-gain-stable buffers capable of driving 400Ω and 20pF to ±1.3V. For applications requiring increased drive capability, the MAX456 outputs can be connected directly to two MAX470 quad, gain-of-two video buffers, which are capable of driving 75Ω loads.

Three-state output capability and internal, programmable active loads make it feasible to parallel multiple MAX456s and form larger switch matrices.

In the 40-pin DIP package, crosstalk (70dB at 5MHz) is minimized, and board area and complexity are simplified by using a straight-through pinout. The analog inputs and outputs are on opposite sides, and each channel is separated by a power-supply line or quiet digital logic line.

________________________Applications

Video Test Equipment Video Security Systems Video Editing

________Typical Application Circuit

8 INPUT CHANNELS

MAX470

= 2

75Ω

OUTPUT

SELECT

INPUT

SELECT

SERIAL

LATCH

MAX456

A2 A1 A0

8 X 8

T-SWITCH

MATRIX D3 D2

OR

D1/SER OUT D0/SER IN

I/O



AV = 2

MAX470

75Ω

____________________________Features

♦ Routes Any Input Channel to Any Output Channel ♦ Switches Standard Video Signals ♦ Serial or Parallel Digital Interface ♦ Expandable for Larger Switch Matrices ♦ 80dB All-Channel Off Isolation at 5MHz ♦ 8 Internal Buffers with:

250V/µs Slew Rate, Three-State Output Capability, Power-Saving Disable Feature, 35MHz Bandwidth

______________Ordering Information

PART TEMP. RANGE PIN-PACKAGE

MAX456CPL 0°C to +70°C 40 Plastic DIP MAX456CQH 0°C to +70°C 44 PLCC MAX456C/D 0°C to +70°C Dice*

Ordering Information continued on last page.

* Dice are specified at T

= +25°C, DC parameters only.

_________________Pin Configurations

TOP VIEW

D1/SER OUT

D0/SER IN

A2 A1

IN0

IN1

LOAD

IN2

DGND

IN3

DGND

IN4

EDGE/LEVEL

IN5

V+

IN6

SER/PAR

IN7

PLCC on last page

1 2 3

MAX456

4 5 6 7 8

9 10 11 12 13 14 15 16 17 18 19

V-

DIP

V+

OUT0

OUT1

OUT2

V-

OUT3

AGND

OUT4

AGND

OUT5

AGND

OUT6

V+

OUT7

LATCH

MAX456

________________________________________________________________

Maxim Integrated Products

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

8 x 8 Video Crosspoint Switch

ABSOLUTE MAXIMUM RATINGS

Total Supply Voltage (V+ to V-) ...........................................+12V

Positive Supply Voltage V+ Referred to AGND......-0.3V to +12V

Negative Supply Voltage V- Referred to AGND.....-12V to +0.3V

DGND Voltage.........................................................AGND ±0.3V

Buffer Short Circuit to Ground when

Not Exceeding Package Power Dissipation.............Indefinite

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

MAX456

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

Input Current, Power On or Off

Digital Inputs.................................................................±20mA

Analog Inputs ...............................................................±50mA

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.

Continuous Power Dissipation (T

40-Pin Plastic DIP (derate 11.3mW/°C above +70°C)....889mW

40-Pin CERDIP (derate 20.0mW/°C above +70°C)....1600mW

44-Pin PLCC (derate 13.3mW/°C above +70°C) .......1066mW

Operating Temperature Ranges:

MAX456C _ _ ......................................................0°C to +70°C

MAX456E _ _ ...................................................-40°C to +85°C

Storage Temperature Range.............................-65°C to +160°C

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

ELECTRICAL CHARACTERISTICS

(V+ = 5.0V, V- = -5.0V, -1.3V ≤ VIN≤ +1.3V; LOAD = +5V; internal load resistors on; AGND = DGND = 0V; TA= +25°C, unless otherwise noted.)

PARAMETER CONDITIONS MIN TYP MAX UNITS

Input Voltage Range -1.3 1.3 V

Internal load

Voltage Gain

Buffer Offset Voltage Offset Voltage Drift TA= T

Operating Supply Voltage ±4.5 ±5.5 V Supply Current, All Buffers On

(No External Load)

Supply Current, All Buffers Off Power-Supply Rejection Ratio ±4.5V to ±5.5V, DC measurement 50 64 dB

Analog Input Current ±0.1 ±10 nA Output Leakage Current

Internal Amplifier Load Resistor (LOAD Pin = 5V)

Buffer Output Voltage Swing Internal load resistors on, no external load ±1.3 V Digital Input Current TA= T Output Impedance at DC 10 Ω Input Logic Low Threshold 0.8 V Input Logic High Threshold 2.4 V SER OUT Output Logic Low 0.4 SER OUT Output Logic High 4

resistors on, no external load, V

= 0V to 1V

TA= +25°C ±7 TA= T

MIN MIN

TA= +25°C 39 45 TA= T

MIN

TA= +25°C TA= T

MIN

TA= T

MIN

Internal load resistors off, all buffers off, TA= T

TA= +25°C 250 400 600 TA= T

MIN

Serial mode, SER/–P—A—R–= 5V

to T to T

to T

MIN

to T

MAX MAX

MAX

to T

MAX

TA= +25°C

TA= T

MAX

to T

MIN

IOL= 1.6mA IOH= -0.4mA

MAX

0.99 1.0 1.01

0.98 1.0 1.02

200 765

= +70°C)

V/V

±12

20 µV/°C

1.5 3.0 4

±100 nA

±1

Ω

µA

2 _______________________________________________________________________________________

8 x 8 Video Crosspoint Switch

ELECTRICAL CHARACTERISTICS

(V+ = 5.0V, V- = -5.0V, -1.3V ≤ VIN≤ +1.3V, LOAD = +5V, internal load resistors on, AGND = DGND = 0V, TA= +25°C, unless otherwise noted.)

PARAMETER CONDITIONS MIN TYP MAX UNITS

DYNAMIC SPECIFICATIONS (Note 1)

X Output-Buffer Slew Rate Single-Channel Crosstalk 5MHz, VIN= 2V All-Channel Crosstalk 5MHz, VIN= 2V All-Channel Off Isolation 5MHz, VIN= 2V

-3dB Bandwidth 10pF load, VIN= 2V Differential Phase Error (Note 4) 1.0 deg Differential Gain Error (Note 4) 0.5 % Input Noise DC to 40MHz 0.3 1.0 mV Input Capacitance All buffer inputs grounded 6 pF

Buffer Input Capacitance Output Capacitance Output buffer off 7 pF

Internal load resistors on, 10pF load 250 V/µs

(Note 2) 60 70 dB

P-P

(Notes 2, 3) 57 dB

P-P

(Note 2) 80 dB

P-P

(Note 2) 25 35 MHz

P-P

RMS

Additional capacitance for each output buffer connected to channel input

2 pF

SWITCHING CHARACTERISTICS (Note 1)

(Figure 4, V+ = 5.0V, V- = -5.0V, -1.3V ≤ VIN≤ +1.3V, LOAD = +5V, internal load resistors on, AGND = DGND = 0V, TA = T

Note 1: Guaranteed by design. Note 2: See Note 3: 3dB typical crosstalk improvement when R Note 4: Input test signal: 3.58MHz sine wave of amplitude 40IRE superimposed on a linear ramp (0 to 100IRE). IRE is a unit of

to T

MIN

Chip-Enable to Write Setup t Write Pulse Width High t Write Pulse Width Low t

Data Setup t Data Hold t

Latch Pulse Width t Latch Delay Switch Break-Before-Make Delay t

LATCH Edge to Switch Off t

LATCH Edge to Switch On t

, unless otherwise noted.)

MAX

PARAMETER

Dynamic Test Circuits

video-signal amplitude developed by the International Radio Engineers. 140IRE = 1.0V.

SYMBOL MIN TYP MAX

ON - tOFF

OFF

on page 11.

CONDITIONS

Parallel mode 32-bit serial mode

LATCH on

= 0Ω.

UNITS

0 ns 80 ns 80 ns

240 160

0 ns 80 ns 80

15 ns 35 ns 50 ns

MAX456

_______________________________________________________________________________________ 3

8 x 8 Video Crosspoint Switch

______________________________________________________________Pin Description

DIP PLCC

— 1, 12, 23, 34 N.C. No connect. Not internally connected.

1 2 D1/SER OUT

MAX456

2 3 D0/SER IN

3, 4, 6 4, 5, 7 A2, A1, A0 Output Buffer Address Lines

5, 7, 9, 11,

13, 15, 17, 19

8 9 LOAD

10, 12 11, 14 DGND

14 16 EDGE/–L—E—V—E—L

16, 26, 40 18, 29, 44 V+

18 20 SER/P—A—R

20, 34 22, 38 V-

21 24 WR

22 25 LATCH

23 26 C—E 24 27 CE

25, 27, 29, 31,

33, 35, 37, 39

28, 30, 32 31, 33, 36 AGND

36 40 D3

38 42 D2

Note 1: Buffer inputs are internally grounded with a 1000 or 1001 command from the D3-D0 lines. AGND must be at 0.0V since the

gain setting resistors of the buffers are internally tied to AGND.

6, 8, 10, 13,

15, 17, 19, 21

28, 30, 32, 35,

37, 39, 41, 43

NAME FUNCTION

Parallel Data Bit D1 when SER/P—A—R–= 0V. Serial Output for cascading multiple parts when SER/P—A—R–= 5V.

Parallel Data Bit D0 when SER/P—A—R–= 0V. A Serial Input when SER/P—A—R–= 5V.

IN0–IN7 Video lnput Lines

Asynchronous control line. When LOAD = 1, all the 400Ω internal active loads are on. When LOAD = 0, external 400Ω loads must be used. The buffers MUST have a resistive load to maintain stability.

Digital Ground Pins. Both DGND pins must have the same potential and be bypassed to AGND. DGND should be within ±0.3V of AGND.

When this control line is high, the 2nd-rank registers are loaded with the rising edge of the LATCH line. If this control line is low, the 2nd-rank reg-

–

isters are transparant when LATCH is low, passing data directly from the 1st-rank registers to the decoders.

All V+ pins must be tied to each other and bypassed to AGND separately (Figure 2).

–

5V = 32-Bit Serial, 0V = 7-Bit Parallel Both V- pins must be tied to each other and bypassed to AGND

separately (Figure 2). WRITE in the serial mode, shifts data in. In the parallel mode, WR loads

data into the 1st-rank registers. Data is latched on the rising edge. If EDGE/–L—E—V—E—L–= 5V, data is loaded from the 1st-rank registers to the 2nd-

rank registers on the rising edge of LATCH. If EDGE/–L—E—V—E—L–= 0V, data is loaded while LATCH = 0V. In addition, data is loaded during the execution of parallel-mode functions 1011 through 1110, or if LATCH = 5V during the execution of the parallel-mode "software-LATCH" command (1111).

–

OUT7-OUT0 Output Buffers 7-0 (Note 1)

–C—h—i—p— —E—n—a—b—l—e– Chip Enable. When –C—E–= 0V and CE = 5V, the WR line is enabled.

Analog Ground must be at 0.0V since the gain resistors of the buffers are tied to these 3 pins.

Parallel Data Bit D3 when SER/ –P—A—R–= 0V. When D3 = 0V, D0-D2 specifies the input channel to be connected to buffer. When D3 = 5V, then D0-D2 specify control codes. D3 is not used when SER/–P—A—R–= 5V.

Parallel Data Bit D2 when SER/–P—A—R–= 0V. Not used when SER/–P—A—R–= 5V.

. When–C—E–= 0V and CE = 5V, the WR line is enabled.

4 _______________________________________________________________________________________

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