The MAX9546/MAX9547 differential interface chipset
converts single-ended voltages to differential voltages for
transport and then converts back to single-ended voltages.
These devices eliminate costly, bulky, single-ended
coaxial cables with inexpensive, readily available,
differential shielded (ScTP) or unshielded (UTP) twisted
pairs. The fault detection of the MAX9546 and loss-of-signal
detection of the MAX9547 allow proactive and
speedy diagnosis, such as identifying failures in the manufacturing
stage and troubleshooting equipment at repair
facilities. The MAX9546/MAX9547 are low-cost, convenient
solutions for transporting CVBS/FBAS analog video
signals (PAL or NTSC) through hostile environments.
The MAX9546 driver converts the single-ended input into
a differential output with a 6dB fixed gain to drive a back-terminated,
DC-coupled differential video output to unity
gain. This DC connection allows the detection of a short-circuit
condition at the differential outputs. The active-low FAULT
output indicates a short-circuit condition including a short
to a high battery condition (VBAT = +16V) or ground.
The MAX9547 receiver converts the differential signal
from the MAX9546 into a single-ended signal. Like the
MAX9546 output, the MAX9547 input survives a short to
a high battery condition or ground. The MAX9547 receiver
loss-of-signal output (active-low LOS) operates by detecting the
H-Sync and thus can support both monochrome and
color video signals. The MAX9547 gain is set with an
external impedance between ZT+ and ZT-.
The MAX9546/MAX9547 operate from a 7.5V to 10V
single supply. Both devices include ±15kV ESD Human
Body Model (HBM) protection. The MAX9546/MAX9547
are offered in a thermally enhanced 8-pin SO package
and specified over the -40°C to +85°C extended temperature
range.
Key Features
Applications/Uses
Fault Detection (MAX9546)
Loss-of-Signal Detection (MAX9547)
Tolerate ±2V Ground-Level Shift between Source and Load