Patent ID: 6188343
Filing Date: 2001-02-13
Classification: G06J

Abstract:
A digitally-controlled voltage gain amplifier circuit capable of non-linear voltage adjustments, comprising:a fine gain amplifier receiving an analog input signal and an analog gain adjustment signal to provide an output analog signal having a value that is a function of said analog input signal and said analog gain adjustment signal; anda gain control circuit receiving a digital value and providing said analog gain adjustment signal, said gain control circuit comprising:a first multiplying digital-to-analog converter receiving a reference voltage and said digital value to provide a first output voltage proportional to said reference voltage and said digital value;a second multiplying digital-to-analog converter receiving said first output voltage and said digital value to provide a second output voltage proportional to said reference voltage and a square of said digital value; anda summing circuit receiving said first and second output voltages and said reference voltage to provide a sum thereof as said analog gain adjustment signal.