SSM2142

Balanced Line Driver

Courtesy/Thanks to: Analog Devices

Description: The SSM2142 is an integrated differential-output buffer
amplifier that converts a single-ended input signal to a balanced
output signal pair with high output drive. By utilizing low noise
thermally matched thin film resistors and high slew rate
amplifiers, the SSM2142 helps maintain the sonic quality of
audio systems by eliminating power line hum, RF interference,
voltage drops, and other externally generated noise commonly
encountered with long audio cable runs. Excellent rejection of
common-mode noise and offset errors is achieved by laser
trimming of the onboard resistors, assuring high gain accuracy.
The carefully designed output stage of the SSM2142 is capable
of driving difficult loads, yielding low distortion performance
despite extremely long cables or loads as low as 600 W, and is
stable over a wide range of operating conditions.

Based on a cross-coupled, electronically balanced topology, the
SSM2142 mimics the performance of fully balanced
transformer-based solutions for line driving. However, the
SSM2142 maintains lower distortion and occupies much less
board space than transformers while achieving comparable
common-mode rejection performance with reduced parts count.
The SSM2142 in tandem with the SSM2141 differential
receiver establishes a complete, reliable solution for driving and
receiving audio signals over long cables. The SSM2141 features
an Input Common-Mode Rejection Ratio of 100 dB at 60 Hz.
Specifications demonstrating the performance of this typical
system are included in the data sheet.