SA2159 Datasheet, PDF (3/11 Pages) Silan Microelectronics Joint-stock – VOLTAGE CONTROLLED AMPLIFIER FOR ELECTRONIC VOLUME CONTROL

PIN CONFIGURATION
SA2159
PIN DESCRIPTION
Pin No.
1
2
3
4
5
6
7
8
Symbol
IN
EC+
EC-
EC+(SYM)
V-
GND
V+
OUT
Signal input
Positive exponential control
Negative exponential control
Symmetry control
Negative power
Ground
Positive power
Output
Description
FUNCTION DESCRIPTION
OPERATING THEORY
The SA2159 VCA is designed for high performance in audio frequency applications which requires exponential
gain control, low distortion, wide dynamic range and low DC bias modulation. The gain control part controls gain
by converting an input current signal to a bipolar logged voltage, adding a DC control voltage and reconverting
the summed voltage back to a current through a bipolar antilog circuit.
The simplified internal circuit diagram of the IC is shown in figure 1. The AC input signal current flows in the
input pin 1, which is maintained at a virtual ground potential by the internal op amp.
Figure 1. Simplified internal circuit diagram
HANGZHOU SILAN MICROELECTRONICS CO.,LTD
Http: www.silan.com.cn
Rev: 1.0 2005.04.22
Page 3 of 11