MAX456 Datasheet, PDF (1/12 Pages) Maxim Integrated Products – 8 x 8 Video Crosspoint Switch

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, out-
put 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 appli-
cations 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, programma-
ble 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 simpli-
fied 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
WR
LATCH
MAX456
MAX470
AV = 2
75Ω
75Ω
OUTPUT
SELECT
INPUT
SELECT
OR
SERIAL
I/O
A2
A1
A0
8X8
T-SWITCH
MATRIX
D3
D2
D1/SER OUT
D0/SER IN
AV = 2
MAX470
____________________________Features
o Routes Any Input Channel to Any Output Channel
o Switches Standard Video Signals
o Serial or Parallel Digital Interface
o Expandable for Larger Switch Matrices
o 80dB All-Channel Off Isolation at 5MHz
o 8 Internal Buffers with:
250V/µs Slew Rate, Three-State Output Capability,
Power-Saving Disable Feature, 35MHz Bandwidth
______________Ordering Information
PART
MAX456CPL
MAX456CQH
MAX456C/D
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
PIN-PACKAGE
40 Plastic DIP
44 PLCC
Dice*
Ordering Information continued on last page.
* Dice are specified at T_A = +25°C, DC parameters only.
_________________Pin Configurations
TOP VIEW
D1/SER OUT ₁
D0/SER IN 2
A2 ₃
A1 ₄
IN0 5
A0 6
IN1 ₇
LOAD ₈
IN2 ₉
DGND ₁₀
IN3 ₁₁
DGND 12
IN4 ₁₃
EDGE/LEVEL ₁₄
IN5 15
V+ 16
IN6 ₁₇
SER/PAR ₁₈
IN7 ₁₉
V- ₂₀
MAX456
PLCC on last page
DIP
40 ^V+
39 OUT0
38 D2
37 OUT1
36 D3
35 OUT2
34 V-
33 OUT3
32 AGND
31 OUT4
30 ^AGND
29 OUT5
28 AGND
27 OUT6
26 V+
25 OUT7
24 CE
23 CE
22 LATCH
21 WR
________________________________________________________________ Maxim Integrated Products 1
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