_______________Detailed Description

The MAX4141 video switch is manufactured with

Maxim’s proprietary complementary bipolar process

that yields high bandwidth and low capacitance. To

maintain a wide bandwidth, the MAX4141 incorporates

a straightforward structure of input and output buffers.

Make-before-break switching is employed to reduce

noise and glitches, even when switching from part to

part in large arrays. The input buffers provide a con-

stant, high input impedance. And, they prevent the

make-before-break action from feeding back to the

input and causing noise and/or glitches.

The design of the switching mechanism limits the

inevitable glitch to within 13mVp-p. In addition, the

glitch pulse is positive to avoid confusion with any neg-

ative sync pulses.

Unity-gain output buffers isolate other inputs from the

switching action of large multiplex arrays. These buffers

can drive 5k

Ω resistive loads. Load capacitance is lim-

ited only by system bandwidth requirements.

The MAX4141 does not contain buffer latches. The digi-

tal inputs control the switch transparently.

__________Applications Information

Grounding, Bypassing,

and PC Board Layout

In order to obtain the MAX4141’s full 330MHz bandwidth,

Microstrip and Stripline techniques are recommended in

most cases. To ensure your PC board does not degrade

the switch’s performance, it’s wise to design the board

for a frequency greater than 1GHz. Even with very short

runs, it’s good practice to use this technique at critical

points, such as inputs and outputs. Whether you use a

constant-impedance board or not, observe the following

guidelines when designing the board:

• Do not use wire-wrap boards, because they are too

inductive.

• Do not use IC sockets. They increase parasitic

capacitance and inductance.

• In general, surface-mount components have shorter

leads and lower parasitic reactance, and give better

high-frequency performance than through-hole com-

ponents.

• The PC board should have at least two layers, with

one side a signal layer and the other a ground plane.

• Keep signal lines as short and as straight as possi-

ble. Do not make 90° turns; round all corners.

• The ground plane should be as free from voids as

possible.

330MHz, 4x1 Precision Video Multiplexer

6

_______________________________________________________________________________________

______________________________________________________________Pin Description

Output Enable and device shutdown. A logic high on this pin enables the output. A logic low

causes the output to assume a high-impedance state and reduces operating current.

EN

9

Negative Power-Supply Voltage. Decouple to power ground.

10

Signal Output

OUT

11

Positive Power-Supply Voltage. Decouple to power ground.

12

Channel Selection Bit. See truth tables.

A1

13

Signal Input

IN2

5

Signal Input

IN3

7

No Connect—not internally connected.

N.C.

8

Signal Input

IN1

3

Analog (Signal) Ground. Since inputs are isolated by these grounds, they should be as noise-free

as possible.

GND

2, 4, 6

PIN

Signal Input

IN0

1

DESCRIPTION

FUNCTION

Channel Selection Bit. See truth tables.

A0

14