Patent ID: 7248198

Claim:
A reference voltage driving circuit for a pipelined ADC, the circuit comprising: a first source follower for receiving a predetermined first reference voltage (REFT) to output a first output voltage (RTOP_MDAC) corresponding to the first reference voltage to a MDAC (Multiplying Digital to Analog Converter); and a second source follower for receiving a second reference voltage (REFC) having a predetermined voltage difference from the first reference voltage, and outputting to the MDAC a second output voltage (RBOT_MDAC) corresponding to the second reference voltage and having the voltage difference, wherein the first source follower comprises: a first transistor whose source is connected to a predetermined source voltage, and receiving a predetermined bias signal via its gate; and a second transistor (MPT 1 ) whose source is connected to a drain of the first transistor and whose drain is connected to ground and receiving the first reference voltage via its gate.