40 dB
OUT B2
IN B
OUT B1
DEC B2
VB
GND
OUT A
IN A
2.2k
VMIC
1
2
4
3
5
10
9
7
6
23 dB
DEC B1
8
DESCRIPTION
The LC550 is a low voltage linear monolithic integrated
circuit amplifier. It is comprised of two separate amplifiers
on a single chip. The first is a 23 dB Class A preamp
followed by a 40 dB Class B output stage.
Both stages incorporate negative feedback to control
gain, minimize distortion and stabilize operation at very
low quiescent currents.
The preamp and output stage have their inputs and outputs
separately pinned out. This is an advantage as it allows
access to both stages, providing the designer with flexibility
and a full range volume control.
The combination of low quiescent current and a medium
power push-pull output makes the LC550 suitable for
medium power BTE hearing aids and for high power ITE
aids where efficiency and battery life are a premium
consideration.
FEATURES
Medium Power
Class B Amplifier
23 dB class A preamp & 40 dB class B output stage
1.0 V DC to 1.7 V DC operating range
2.2 k
on chip microphone decoupling resistor
350
A typical quiescent current
400 Hz to 20 kHz frequency response
STANDARD PACKAGING
10 pin MICROpac
10 pin MINIpac
10 pin SLT
10 pin PLID
Chip (57 x 47 mils)
Au Bump
BLOCK DIAGRAM
All resistors in ohms, all capacitors in
F unless otherwise stated.
U.S. Patent No. 4,085,382, patented in other countries.
LC550 DATA SHEET
Document No. 500 - 37 - 8
GENNUM CORPORATION P.O. Box 489, Stn A, Burlington, Ontario, Canada L7R 3Y3
tel. (905) 632-2996 fax: (905) 632-5946
Japan Branch: A-302, M i yamae Vi l l age, 2–10–42 M i yamae, Suginami–ku, Tokyo 168, Japan
tel. (03) 3334-7700
fax (03) 3247-8839
Revision Date: December 1994