FUNCTIONAL BLOCK DIAGRAM
+OUT FORCE
– OUT FORCE
– OUT SENSE
+OUT SENSE
10kΩ
10kΩ
50Ω
50Ω
V
IN
GND
ALL RESISTORS 30kΩ
UNLESS OTHERWISE
INDICATED
REV. B
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
a
Balanced Line Driver
SSM2142
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700 Fax: 617/326-8703
FEATURES
Transformer-Like Balanced Output
Drives 10 V RMS Into a 600 V Load
Stable When Driving Large Capacitive Loads and Long
Cables
Low Distortion
0.006% typ 20 Hz–20 kHz, 10 V RMS into 600 V
High Slew Rate
15 V/ms typ
Low Gain Error
(Differential or Single-Ended); 0.7% typ
Outputs Short-Circuit Protected
Available In Space-Saving 8-Pin Mini-DIP Package
Low Cost
APPLICATIONS
Audio Mix Consoles
Distribution Amplifiers
Graphic and Parametric Equalizers
Dynamic Range Processors
Digital Effects Processors
Telecommunications Systems
Industrial Instrumentation
Hi-Fi Equipment
GENERAL 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 Ω, 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.
