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CLC522

Wideband Variable-Gain Amplifier

General Description

The CLC522 variable gain amplifier (VGA) is a dc-coupled, two-

quadrant multiplier with differential voltage inputs and a single-ended

voltage output. Two input buffers and an output operational amplifer

are integrated with the multiplier core to make the CLC522 a complete

VGA system that does not require external buffering.

The CLC522 provides the flexibility of externally setting the maximum

gain with only two external resistors. Greater than 40dB gain control

is easily achieved through a single high impedance voltage input. The

CLC522 provides a linear (in Volts per Volt) relationship between the

amplifier's gain and the gain-control input voltage.

The CLC522's maximum gain may be set anywhere over a nominal

range of 2V/V to 100V/V. The gain control input then provides

attenuation from the maximum setting. For example, set for a

maximum gain of 100V/V, the CLC522 will provide a 100V/V to 1V/V

gain control range by sweeping the gain control input voltage from +1

to -0.98V.

Set at a maximum gain of 10V/V, the CLC522 provides a 165MHz

signal channel bandwidth and a 165MHz gain control bandwidth. Gain

nonlinearity over a 40dB gain range is 0.5% and gain accuracy at

June 1999

Features

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330MHz signal bandwidth: A

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165MHz gain-control bandwidth

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0.3° to 60MHz linear phase deviation

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0.04% (-68dB) signal-channel non-linearity

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>40dB gain-adjustment range

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Differential or single-end voltage inputs

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Single-ended voltage output

Applications

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Variable attenuators

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Pulse amplitude equalizers

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HF modulators

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Automatic gain control & leveling loops

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Video production switching

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Differential line receivers

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Voltage controlled filters

© 1999 National Semiconductor Corporation

http://www.national.com

Printed in the U.S.A.

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Typical Application

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2nd Order Tuneable Bandpass Filter

Pinout

DIP & SOIC