公开(公告)号：US20020063648A1

公开(公告)日：2002-05-30

申请号：US09972751

申请日：2001-10-05

Applicant: STMicroelectronics S.r.I.

Inventor： Cristiano Meroni ,  Edoardo Botti ,  Andrea Baschirotto ,  Massimo Ghioni

IPC: H03M001/66

CPC classification number: H03M1/0682 ,  H03M1/0665 ,  H03M1/74

Abstract: A method for digital-to-analog conversion of a digital input code into a first output analog signal and a second output analog signal to be supplied to a first terminal and a second terminal, respectively, of an audio load, the conversion being performed by means of a DAC with N-level balanced output, the conversion method includes using N/2 positive generator elements supplying respective positive elementary contributions which are nominally equal to one another, and N/2 negative generator elements supplying respective negative elementary contributions which are nominally equal to one another and, in absolute value, equal to the positive elementary contributions; attributing the same progressive addresses to the positive generator elements and to the negative generator elements; defining a first index for the positive input codes and a second index for the negative input codes; and, in the presence of an input code at the input of the DAC, selecting between the first index and the second index, the index corresponding to the sign of the input code; activating a first set of positive generator elements and a second set of negative generator elements, the number of the positive generator elements activated and the number of the negative generator elements activated being equal to one another and proportional to the input code, and the addresses of the positive generator elements activated and of the negative generator elements activated being a function of the selected index; generating the first output analog signal by summing the positive elementary contributions supplied by the positive generator elements activated, and generating the second output analog signal by summing the negative elementary contributions supplied by the negative generator elements activated; and updating the selected index according to the input code.