# US 2014/0197974 A1 · Digital to analog converter and method for controlling current source array in digital to analog converter

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- Number: US 2014/0197974 A1
- Document ID: US20140197974A1
- Status: Published application
- Kind: A1
- Application number: 14/142,597
- Filed: 2013-12-27
- Published: 2014-07-17
- Earliest claimed: 2013-01-14
- Assignees: Huawei Technologies Co., Ltd.
- Applicants: Huawei Technologies Co., Ltd.
- Inventors: Haiquan YUAN; Peng GAO
- Web page: https://patentgrep.com/patent/US20140197974A1

## CPC

- H03M 1/685: {the quantisation value generators of both converters being arranged in a common two-dimensional array}
- H03M 1/747: {with equal currents which are switched by unary decoded digital signals}
- H03M: CODING; DECODING; CODE CONVERSION IN GENERAL (using fluidic means F15C4/00; optical analogue/digital converters G02F7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G01D, G01R, G06F, G06T, G09G, G10L, G11B, G11C, H04B, H04L, H04M, H04N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G09C)

## Abstract

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.

## Claims

### Claim 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; and
n is a positive integer.

### Claim 2 (depends on 1)

The digital to analog converter according to claim 1, wherein the first diagonals are non-middle diagonals and the second diagonal is a middle diagonal.

### Claim 3 (depends on 2)

The digital to analog converter according to claim 2, wherein n is greater than or equal to 3, and the switching all unit switches on a second diagonal except the 2n−1 first diagonals in the 2n×2n matrix according to a preset sequence comprises:
switching all 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.

### Claim 4 (depends on 3)

The digital to analog converter according to claim 3, wherein the switching all unit switches on the second diagonal in ascending order of distances away from two quartering points except the midpoint on the second diagonal in the 2n×2n matrix comprises:
firstly switching a unit switch which is a first distance away from one quartering point of the two quartering points, and then symmetrically switching a unit switch which is the first distance away from the other quartering point of the two quartering points.

### Claim 5 (depends on 1)

The digital to analog converter according to claim 1, wherein the decoding module comprises:
a first decoder, configured to decode the high n bits of the 2n-bit binary digital signal to obtain the 2n−1-bit first temperature code;
a second decoder, configured to decode the low n bits of the 2n-bit binary digital signal to obtain the 2n−1-bit second temperature code; and
a control module, configured to control, by using the 2n−1-bit first temperature code and the 2n−1-bit second temperature code, the working sequence of the 2n×2n−1 unit switches in the manner.

### Claim 6 (depends on 5)

The digital to analog converter according to claim 5, wherein the control module is specifically configured to control, under the control of a software driver and by using the 2n−1-bit first temperature code and the 2n−1-bit second temperature code, the working sequence of the 2n×2n−1 unit switches in the manner.

### Claim 7

A method for controlling a current source array in a digital to analog converter, wherein the digital to analog converter comprises a switch array and a current source array connected to the switch array; 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; outputs of the 2n×2n−1 unit current source are used to generate an output of the digital to analog converter; n is a positive integer; and the method comprises:
generating a 2n−1-bit first temperature code by using high n bits of an input 2n-bit binary digital signal, and generating 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; and
controlling, 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.

### Claim 8 (depends on 7)

The control method according to claim 7, wherein the first diagonals are non-middle diagonals and the second diagonal is a middle diagonal.

### Claim 9 (depends on 8)

The control method according to claim 8, wherein n is greater than or equal to 3, and the switching all unit switches on a second diagonal except the 2n−1 first diagonals in the 2n×2n matrix according to a preset sequence comprises:
switching all 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.

### Claim 10 (depends on 9)

The control method according to claim 9, wherein the switching all unit switches on the second diagonal in ascending order of distances away from two quartering points except the midpoint on the second diagonal in the 2n×2n matrix comprises:
firstly switching a unit switch which is a first distance away from one quartering point of the two quartering points, and then symmetrically switching a unit switch which is the first distance away from the other quartering point of the two quartering points.

### Claim 11

A method for controlling a current source array in a digital to analog converter, used to control outputs of unit current sources comprised in the current source array, wherein the current source array comprises 2n×2n−1 unit current sources, n is a positive integer, and the method comprises:
generating a 2n−1-bit first temperature code by using high n bits of an input 2n-bit binary digital signal, and generating 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;
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×(2−1) high-order unit switches, so as to control outputs of unit current sources corresponding to the 2n×(2−1) high-order unit switches in the current source array; 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, so as to control outputs of unit current sources corresponding to the 2n−1 low-order unit switches in the current source array.

### Claim 12 (depends on 11)

The control method according to claim 11, wherein the first diagonals are non-middle diagonals and the second diagonal is a middle diagonal.

### Claim 13 (depends on 12)

The control method according to claim 12, wherein n is greater than or equal to 3, and the 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 comprises:
switching all 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 by using the 2n−1-bit second temperature code, wherein the two quartering points are 2n-2 elements away from the midpoint.

### Claim 14 (depends on 13)

The control method according to claim 13, wherein the switching all unit switches on the second diagonal in ascending order of distances away from two quartering points except the midpoint on the second diagonal in the 2n×2n matrix comprises:
firstly switching a unit switch which is a first distance away from one quartering point of the two quartering points, and then symmetrically switching a unit switch which is the first distance away from the other quartering point of the two quartering points.