US Patent 10312925 Multiplying DAC of pipelined ADC

This invention discloses a multiplying digital-to-analog converter (MDAC) applied to a pipelined analog-to-digital converter (pipelined ADC). The MDAC includes an operational amplifier. The MDAC samples a differential input signal in a sampling phase and performs subtraction and multiplication operations in an amplification phase according to a first reference voltage and a second reference voltage. The common-mode voltage of the first reference voltage and the second reference voltage is not substantially equal to the common-mode voltage of the differential input signal; and/or the voltage difference between the first reference voltage and the second reference voltage is not substantially equal to one half of an allowed maximum peak-to-peak value of the differential input signal. One of the first reference voltage and the second reference voltage can be ground.