Correction method and correction circuit for sigma-delta modulator

Patent metadata

Field	Value
Publication number	US-10742230-B2
Application number	US-201916519739-A
Country	US
Kind code	B2
Filing date	Jul 23, 2019
Priority date	Sep 17, 2018
Publication date	Aug 11, 2020
Grant date	Aug 11, 2020

Abstract

A correction method and a correction circuit for a sigma-delta modulator (SDM) are disclosed. The SDM includes a loop filter, a quantizer, and a digital-to-analog converter (DAC), and the loop filter includes a resonator. The correction circuit includes a memory and a control circuit. The memory stores multiple program instructions. The control circuit executes the program instructions to correct the SDM. The correction procedure of the SDM includes the following steps: inputting a test signal to the SDM; obtaining a signal characteristic value of an output signal of the SDM; and adjusting the resonator according to the signal characteristic value.

First claim

What is claimed is:

1. A correction method for correcting a sigma-delta modulator (SDM), the SDM comprising a loop filter, a quantizer, and a digital-to-analog converter (DAC), the loop filter comprising a resonator, and the correction method comprising following steps:
inputting a test signal to the SDM;
obtaining a signal characteristic value of an output signal of the SDM, wherein the signal characteristic value is a signal-to-noise ratio (SNR), an error vector magnitude (EVM), or a noise intensity of the output signal; and
adjusting the resonator according to the signal characteristic value.

2. The correction method of claim 1 , wherein the resonator comprises a first integrator, a second integrator, and an impedance, and the step of adjusting the resonator according to the signal characteristic value adjusts the impedance.

3. The correction method of claim 1 , wherein the step of obtaining the signal characteristic value of the output signal of the SDM obtains the signal characteristic value in an operating frequency band of the SDM.

4. A correction circuit for correcting a sigma-delta modulator (SDM), the SDM comprising a loop filter, a quantizer, and a digital-to-analog converter (DAC), the loop filter comprising a resonator, the correction circuit comprising:
a memory configured to store a plurality of program instructions; and
a control circuit coupled to the memory and configured to execute the program instructions to correct the SDM;
wherein the control circuit corrects the SDM by performing following steps:
inputting a test signal to the SDM;
obtaining a signal characteristic value of an output signal of the SDM, wherein the signal characteristic value is a signal-to-noise ratio (SNR), an error vector magnitude (EVM), or a noise intensity of the output signal; and
adjusting the resonator according to the signal characteristic value.

5. The correction circuit of claim 4 , wherein the resonator comprises a first integrator, a second integrator, and an impedance, and the step of adjusting the resonator according to the signal characteristic value adjusts the impedance.

6. The correction circuit of claim 4 , wherein the step of obtaining the signal characteristic value of the output signal of the SDM obtains the signal characteristic value in an operating frequency band of the SDM.

Assignees

• Realtek Semiconductor Corp

Inventors

• Chen Chih-Lung
• Lai Jie-Fan
• Chen Yu-Chang
• Huang Shih-Hsiung

Classifications

• H03M3/404 Primary

  characterised by the type of bandpass filters used · CPC title

• H03M3/458

  Analogue/digital converters using delta-sigma modulation as an intermediate step · CPC title

• H03M3/378

  Testing · CPC title

• H03M1/06

  Continuously compensating for, or preventing, undesired influence of physical parameters (periodically, {e.g. by using stored correction values,} H03M1/10) · CPC title

• H03M3/368 Primary

  of noise other than the quantisation noise already being shaped inherently by delta-sigma modulators · CPC title