Digitally Controlled Variable Gain Amplifier
Original Publication Date: 1981-Mar-01
Included in the Prior Art Database: 2005-Feb-10
In the amplifier shown above, a Gilbert Cell is used with a digital/ analog converter (DAC) to digitally control the gain between VIN and VOUT. A seven-bit binary word is applied to the DAC to generate reference currents varying in magnitude. These reference currents are used to change the current gain of the Gilbert Cell. The input voltage VIN is converted to a current which is multiplied by the Gilbert Cell and converted to the output voltage VOUT.