Patent ID: 6198418
Filing Date: 2001-03-06
Classification: H03M

Abstract:
A digital-to-analog converter comprising:a first power supply node supplied with a first electric current from an electric power source outside thereof;a second power supply node electrically isolated from said first power supply node, and supplied with a second electric current from said electric power source;an output node for supplying an analog output signal therefrom to outside thereof;a resistor circuit connected between said first power supply node and said output node for producing said analog output signal from said first electric current;a plurality of constant current sources connected in parallel to a third power supply node different in potential level from said first power supply node and said second power supply node; anda switching circuit includinga plurality of first switching elements connected between said second power supply node and said plurality of constant current sources and respectively supplied with data bits of a digital input signal for changing current paths thereof between on-state and off-state depending upon said data bits anda plurality of second switching elements respectively paired with said plurality of first switching elements, connected between said resistor circuit and said plurality of constant current sources and supplied with a reference voltage for changing current paths thereof between said on-state and said off-state complementarily to said associated first switching elements.