January 2001
CLC522
Wideband Variable Gain Amplifier
n Differential or single end voltage inputs
n Single-ended voltage output
General Description
The CLC522 variable gain amplifier (VGA) is a dc-coupled,
two-quadrant multipliers with differential voltage inputs and a
single-ended voltage output. Two input buffers and an output
operational amplifier are integrated with the multiplier core
and make the CLC522 a complete VGA system that does not
require external buffering.
Applications
n Variable attenuators
n Pulse amplitude equalizers
n HF modulators
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.
n Automatic gain control & leveling loops
n Video production switching
n Differential line receivers
n Voltage controlled filters
Gain vs. Gain Control Voltage (Vg)
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 ex-
ample, 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 con-
trol bandwidth. Gain nonlinearity over a 40dB gain range is
±
0.5% and gain accuracy at AVmax = 10V/V is typically 0.3%.
Features
n 330MHz signal bandwidth: AVmax = 2
n 165MHz gain control bandwidth
n 0.3˚ to 60MHz linear phase deviation
n 0.04% (−68dB) signal-channel non-linearity
DS012718-1
>
n
40dB gain adjustment range
Connection Diagram
DS012718-4
Pinout
DIP & SOIC
© 2001 National Semiconductor Corporation
DS012718
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