Differential Video Interface Chipset

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Detailed Description

The MAX9546/MAX9547 differential interface chipset

converts single-ended voltages to differential voltages

for transport and then converts back to single-ended

voltages. The chipset is optimized for transporting

CVBS/FBAS analog video signals (PAL or NTSC)

through hostile automotive environments. The

MAX9546 driver includes a fault output (FAULT) that

indicates shorted transmission cables. The MAX9547

receiver loss-of-signal output (LOS) indicates an

absence of input signal.

The MAX9546/MAX9547 operate from a 7.5V to 10V sin-

gle supply. The differential interface is immune to short-

ESD (Human Body Model) protection.

MAX9546

Driver

The MAX9546 driver converts a single-ended video

input into a differential output for transport across a

twisted pair of wires. The input is AC-coupled and the

video signal sync tip is clamped at 3.46V to set the

voltage of the input. The output common-mode voltage

is optimized to reject ground differences between the

MAX9546 and MAX9547 up to ±2V. The differential

gain is internally set to 2V/V to drive a back-terminated

output to unity gain. The maximum input resistance

should not exceed 400Ω to ensure device stability.

Pin Description (MAX9546)

PIN

NAME

FUNCTION

1, 8

Power Supply. Connect together and bypass with a 0.1µF in parallel with a 4.7µF capacitor to

GND.

2

IN

Video Input

3

FAULT

Fault Indicator. Active-low, open-drain output.

FAULT = low when fault is detected at the output.

FAULT = high when no fault is detected at the output.

4, 5

GND

Ground

6

OUT-

Negative Differential Output

7

OUT+

Positive Differential Output

EP

EP

Exposed Paddle. Connect to GND.

Pin Description (MAX9547)

PIN

NAME

FUNCTION

1

IN+

Positive Differential Input

2

ZT+

Positive Transconductance Terminal

3

ZT-

Negative Transconductance Terminal

4

IN-

Negative Differential Input

5

GND

Ground

6

LOS

Loss-of-Signal Indicator. Active-low, open-drain output.

LOS = low when no signal is detected at

the input.

LOS = high when signal is present at the input.

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IOUT

Current Output

Power Supply. Bypass with a 0.1µF capacitor in parallel with a 4.7µF capacitor to GND.

EP

EP

Exposed Paddle. Connect to GND.