Patent ID: 6400299
Filing Date: 2002-06-04
Classification: H03M

Abstract:
A digital/analog converter for converting 2n-bit input digital data into an analog output voltage where n is 2, 3, . . . , comprising:2n capacitors, a (2kâˆ’1)-th one of said capacitors having a unit capacitance, a 2k-th one of said capacitors having a capacitance twice said unit capacitance, a first terminal of said (2kâˆ’1)-th capacitor being connected to a first terminal of said 2k-th capacitor, where k is 1, 2, . . . , n; (nâˆ’1) coupling capacitors, an m-th one of said coupling capacitors being connected between the first terminal of said 2m-th capacitor and the first terminal of said (2m+1)-th capacitor, an (nâˆ’1)-th one of said coupling capacitors being connected to said output terminal, the first coupling capacitor having said unit capacitance, an mâ€²-th one of coupling capacitors having a capacitance of said unit capacitance plus a quarter of the capacitance of an (mâ€²âˆ’1)-th one of said coupling capacitors, where m is 1, 2, . . . , nâˆ’1 and mâ€² is 2, 3, . . . , nâˆ’1; and 2n analog switches, each responsive to one of said 2n input digital data and connected between a second terminal of one of said capacitors and two power supply sources.