This article introduces the LTC6412, Linear Technology's first high frequency, analog-controlled VGA—now added to Linear Technology's existing portfolio of digitally controlled VGAs.
The document introduces the LTC6412, Linear Technology's first high-frequency, analog-controlled Variable Gain Amplifier (VGA). It highlights the device's use in communications and imaging applications such as cellular radio, satellite receivers, radar, and ultrasound. The text compares analog versus digital control methods for VGAs, noting that while digital is common, analog solutions are necessary when system parameters are unknown or RF signals cannot tolerate step disturbances.
The device provides a variable gain range from -14dB to +17dB.
The settling time is 400ns and remains roughly independent of the step size.
The circuit runs off a 3.3V supply with a nominal total current of 110mA.