FUNCTIONAL BLOCK DIAGRAM

–IN

+IN

GAIN

CORE

G

1–G

SSM2018T

FEATURES

117 dB Dynamic Range

0.006% Typical THD+N (@ 1 kHz, Unity Gain)

140 dB Gain Range

No External Trimming Required

Differential Inputs

Complementary Gain Outputs

Buffered Control Port

I–V Converter On-Chip

Low External Parts Count

Low Cost

Trimless

Voltage Controlled Amplifiers

SSM2018T

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 that

may result from its use. No license is granted by implication or otherwise

under any patent or patent rights of Analog Devices.

REV. B

a

NEW

E GRADE

0.0

1%

THD+N

MAX

GENERAL DESCRIPTION

The SSM2018T represents continuing evolution of the Frey

Operational Voltage Controlled Element (OVCE) topology that

permits flexibility in the design of high performance volume

control systems. The SSM2018T is laser trimmed for gain core

symmetry and offset. As a result, the SSM2018T is the first

professional audio quality VCA to offer trimless operation.

Due to careful gain core layout, the SSM2018T combines the

low noise of Class AB topologies with the low distortion of

Class A circuits to offer an unprecedented level of sonic trans-

parency. Additional features include differential inputs, a 140 dB

(–100 dB to +40 dB) gain range and a high impedance control

port. The SSM2018T provides an internal current-to-voltage

converter. Thus no external active components are required.

This device is offered in 16-lead plastic DIP and SOIC packages

and guaranteed for operation over the extended industrial tempera-

ture range of –40

∞C to +85∞C.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781/329-4700

www.analog.com

Fax: 781/326-8703

©Analog Devices, Inc., 2002