LD502 Datasheet, PDF (1/4 Pages) List of Unclassifed Manufacturers – Low Distortion AGC Compression Amplifier

FEATURES
• adjustable gain from 0 to 60 dB
• 0.94 V DC voltage regulator on-chip
• attack time fixed at less than 1 ms
• release time adjustable from 40 to 500 ms
• low input referred noise 1.2 µV
• <1 % distortion at 10 mVRMS output
• operates from 1.05 to 3 VDC
STANDARD PACKAGING
• 8 pin MICROpac
• 8 pin MINIpac
• 8 pin PLID ^®
• 8 pin SLT
• Chip (64 x 62 mils)
Au Bump
Low Distortion AGC
Compression Amplifier
LD502 DATA SHEET
DESCRIPTION
The LD502 is a compression (AGC) preamplifier that consists
of a single ended input inverting amplifier, with an internal
current controlled resistance connected between input and
output.
By using R_GT (see test circuit) to vary the value of this current
controlled resistance, the amplifier gain and compression
threshold can be controlled over a range of 60 dB.
The AGC current is derived from a full wave rectifier driven by
a differential amplifier. The attack time of the AGC circuit is
fixed at less than 1 ms. The release time is adjustable from
40 to 500 ms by selecting the value of an external capacitor
(C3).
Internally, a series shunt voltage regulator produces a 0.94 V
DC regulated output voltage. This provides a bias for electret
microphones and permits circuit operations over a wide range
of supply voltages, 1.05 to 3 VDC for LD502 without any
degradation of electrical performances.
2
V_REG
V_B
7
VOLTAGE
REGULATOR
1
A IN
GAIN SET
4
AMPLIFIER
A OUT
3
8
GND
FULL WAVE
RECTIFIER
5
AGC FILTER
AGC IN
6
BLOCK DIAGRAM
Patented 1985
Canada 1183580
Patent Pending Europe 83.300836.0
USA 4506169
Japan 58-06886
Revision Date: March 1994
Document No. 500 - 43 - 18
GENNUM CORPORATION P.O. Box 489, Stn A, Burlington, Ontario, Canada L7R 3Y3 tel. [phone] fax: [phone]
Japan Branch: A-302, M i yamae Vi l l age, 2–10–42 M i yamae, Suginami–ku, Tokyo 168, Japan tel. [phone] fax [phone]