Low-Power, Variable-Gain Amplifier Sets New Standards In Signal- And Gain-Channel Bandwidth

April 4, 1997 -- National Semiconductor Corporation® today announced a new low-power, low-cost addition to its popular line of high-speed, variable-gain amplifiers. The CLC5523 combines a wide 250MHz bandwidth with the industry's fastest gain-control response rate, the greatest "maximum-gain" range flexibility and the lowest power consumption.

"With nearly three times the signal-channel bandwidth and more than ten times faster gain-control response rate than its closest competitor, the CLC5523 represents a significant advance in high-speed VGAs," said Jeff Hooker, marketing manager for National Semiconductor's Comlinear Products Group. "The fact that it offers this large improvement in performance at less power and at a lower cost than most competitive parts will make the device particularly attractive in very fast signal leveling and automatic gain-control loops."

The CLC5523 combines a high-performance voltage-controlled gain block with a fast current feedback output amplifier. Maximum gain, adjustable between 2 and 100, is set by two external resistors. The gain attenuation range is then greater than 60dB using a gain-control input signal between 0 and 2V. Gain-control response rate is greater than 4dB/nsec. Power consumption is only 135mW.

With its extremely high slew rate (1800V/microsecond) and wide bandwidth (250MHz), the CLC5523 delivers high-speed rise and fall times of 2.0ns for a 0.5V step. Settling time to 0.2% is only 22ns for a 2V step. Other key specifications include gain flatness of less than 0.2dB DC to 75MHz and a low input voltage noise of 4nV/rtHz.

With its combination of wide signal-channel and gain-control bandwidth, high slew rate, low power consumption and low price, the CLC5523 is expected to find widespread use in applications such as automatic gain control, voltage controlled filters, automatic signal leveling for ADCs, amplitude modulation and variable-gain transimpedance devices.

Price and Availability
The CLC5523 is available now in industrial-screened versions ( )40 to +85C) in 8-pin CLC5523IN plastic DIP and CLC5523IM plastic SOIC packages. U.S. list price in either package is $3.75 in 1000s.

For further information on the CLC5523, visit our World Wide Web site at http//www.national.com/pf/CL/CLC5523.html.

National Semiconductor Corporation produces system-on-a-chip silicon solutions for the information highway, based on its leadership in analog and mixed signal technologies. National is headquartered in Santa Clara, California, and focuses on the communications, personal systems and consumer markets. In March, 1997 National sold its Fairchild Semiconductor businesses and now has 12,300 employees worldwide with annual sales of approximately $2.0 billion. Additional company and product information is available on the World Wide Web at www.national.com.

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