GENERAL DESCRIPTION

The SSM-2120 is a monolithic integrated circuit designed for the

purpose of processing dynamic signals in various analog sys-

tems including audio. This “dynamic range processor” consists

of two VCAs and two level detectors (the SSM-2122 consists of

two VCAs only). These circuit blocks allow the user to logarith-

mically control the gain or attenuation of the signals presented

to the level detectors depending on their magnitudes. This al-

lows the compression, expansion or limiting of AC signals, some

of the primary applications for the SSM-2120.

Precision Monolithics Inc.

®

®

SSM-2120/SSM-2122

DYNAMIC RANGE

PROCESSOR/DUAL VCA

FEATURES

The SSM-2120/SSM-2122 is mask work protected under the Semiconductor Chip

Protection Act of 1983.

APPLICATIONS

–10

°C to +50°C

OPERATING

TEMPERATURE

RANGE

ORDERING INFORMATION

PACKAGE

SSM2120P

PLASTIC

22-PIN

SSM2122P

PLASTIC

16-PIN

SIMPLIFIED SCHEMATIC (VCA Section Only)

PIN CONNECTIONS

1

2

3

4

21

22

THRESH 1

GND

LOG AV 1

V+

CON

OUT 1

SIG

OUT 2

SIG

OUT 1

5

20

+V

C1

CFT 2

6

19

CFT 1

–V

C2

7

18

–V

C1

SIG

IN 2

8

17

SIG

IN 1

REC

IN 2

9

16

REC

IN 1

CON

OUT 2

10

15

I

REF

LOG AV 2

11

14

V–

THRESH 2

12

13

1

2

3

413

14

15

16

GND

GND

SIG

OUT 1

V+

+V

C1

SIG

OUT 2

CFT 1

+V

C2

512

–V

C1

CFT 2

611

SIG

IN 1

–V

C2

7

I

REF

SIG

IN 2

89

V–

GND

10

SSM-2122

16-PIN PLASTIC DIP

(P-Suffix)

SSM-2120

22-PIN PLASTIC DIP

(P-Suffix)

5/90, Rev. B1

V+

V–

CURRENT

MIRRORS

V+

36k

Ω

36k

Ω

SIGNAL

OUT

SIGNAL

INPUT

V+

V+

OBSOLETE