Digital to analog converter and method for controlling current source array in digital to analog converter

摘要

A digital to analog converter and a method for controlling a current source array in a digital to analog converter relate to the field of electronics technologies, and are used to reduce a system error. The digital to analog converter includes: a decoding module, a switch array, and a current source array, where the decoding module is configured to generate a 2n−1-bit first temperature code by using high n bits of an input 2n-bit binary digital signal, generate a 2n−1-bit second temperature code by using low n bits of the 2n-bit binary digital signal, and control, by using the 2n−1-bit first temperature code and the 2n−1-bit second temperature code, a working sequence of 2n×2n−1 unit switches.

主权项

1. A digital to analog converter, comprising: a decoding module, a switch array connected to the decoding module, and a current source array connected to the switch array, wherein:
the switch array comprises 2n×2n−1 unit switches, which comprise 2n×(2n−1) high-order unit switches and 2n−1 low-order unit switches; the current source array comprises 2n×2n−1 unit current sources; each unit switch is configured to control an output of one unit current source; and outputs of the 2n×2n−1 unit current sources are used to generate an output of the digital to analog converter; the decoding module is configured to generate a 2n−1-bit first temperature code by using high n bits of an input 2n-bit binary digital signal, and generate a 2n−1-bit second temperature code by using low n bits of the 2n-bit binary digital signal, wherein any bit of the 2n−1-bit first temperature code is used to control 2n high-order unit switches, and any bit of the 2n−1-bit second temperature code is used to control one low-order unit switch; the decoding module is further configured to control, by using the 2n−1-bit first temperature code and the 2n−1-bit second temperature code, a working sequence of the 2n×2n−1 unit switches in the following manner: switching, by using the 2n−1-bit first temperature code, all unit switches on any one of 2n−1 first diagonals in a 2n×2n matrix formed by the 2n×2n−1 unit switches, wherein all elements on the 2n−1 first diagonals correspond to the 2n×(2n−1) high-order unit switches; and switching all unit switches on a second diagonal except the 2n−1 first diagonals in the 2n×2n matrix according to a preset sequence and by using the 2n−1-bit second temperature code, wherein 2n−1 elements on the second diagonal correspond to the 2n−1 low-order unit switches; wherein n is a positive integer which is greater than or equal to 3, and the first diagonals are non-middle diagonals and the second diagonal is a middle diagonal; and switching all the unit switches on the second diagonal except the 2n−1 first diagonals in the 2n×2n matrix according to the preset sequence comprises: switching all the unit switches on the middle diagonal in ascending order of distances away from two quartering points except the midpoint on the middle diagonal in the 2n×2n matrix, wherein the two quartering points are 2n-2 elements away from the midpoint.