800-MHz VGA Boasts 31-dB Analog Control Range

The LTC6412 800-MHz analog-controlled variable gain amplifier (VGA) offers excellent noise and distortion performance, gain conformance, and gain flatness. The device’s gain control is highly linear and the guaranteed maximum conformance error is 0.45dB. Optimized for operation from 1 MHz to 500 MHz, the VGA provides continuous gain adjustment from -14 dB to 17 dB. Third-order output intercept point (OIP3) is 35 dBm at 240 MHz across all gain settings. The LTC6412 also achieves a constant output noise level over the entire gain range, with a noise figure of 10dB at the maximum gain setting. This results in a constant SFDR characteristic, remaining at greater than 120 dB at 240 MHz over the full gain control range. The device’s gain is controlled with either a positive or negative slope control voltage. Using negative gain slope mode, the gain control slope is approximately -32dB/V at 140 MHz, with a control range of 0.1 V to 1.1 V. The LTC6412 consumes 110 mA on a 3.3-V supply. It also includes a shutdown pin, reducing the current consumption to below 1 mA for power-down or sleep modes. The LTC6412 is available in a 4-mm x 4-mm 24-pin QFN package. Starting at $4.69 in 1000-piece quantities, the LTC6412 is offered in commercial- and industrial-grade versions. LINEAR TECHNOLOGY CORP., Milpitas, CA. (408) 432-1900.