Wideband digitally-controlled variable-gain amplifier

Designed for DC to radio frequency (RF), intermediate frequency (IF), and high-speed time-domain applications, the Texas Instruments (TI) LMH6401 is a versatile wideband, digitally-controlled, variable-gain amplifier (DVGA). The device is an ideal analog-to-digital converter (ADC) driver for DC- or AC-coupled applications that require an automatic gain control (AGC), says the company. Noise and distortion performance is optimized to drive ultra-wideband ADCs. The amplifier has an 8dB noise figure at maximum gain and a -63-dBc harmonic distortion at 1GHz for full-scale signal levels. The device supports both single- and split-supply operation for driving an ADC. A common-mode reference input pin is provided to align the amplifier output common-mode with the ADC input requirements. Gain control is performed via an SPI interface, allowing a 32-dB gain range from -6dB to 26dB in 1dB steps. A power-down feature is also available through the external PD pin or SPI control. This level of performance is achieved at a low power level of 345mW. The operating ambient temperature range is -40C to 85C.