Patent ID: 9013340
Filing Date: 2015-04-21
Classification: H02M,H03M

Abstract:
1. A protection circuit for an analog-to-digital converter, wherein the protection circuit comprises: a first gain module, configured to receive a first input signal, and scale the first input signal according to a first scaling factor, to obtain a first analog signal, wherein the first gain module is further configured to receive a second input signal, receive a third scaling factor from a processing module, and scale the second input signal according to the third scaling factor, to obtain a second analog signal; an analog-to-digital converter, configured to convert the first analog signal obtained by the first gain module into a first digital signal, and configured to convert the second analog signal obtained by the first gain module into a second digital signal; the processing module, configured to determine, according to a voltage value of the first digital signal converted by the analog-to-digital converter and a preset scaling factor determining rule, the third scaling factor corresponding to the voltage value of the first digital signal, wherein the scaling factor determining rule comprises that: if the voltage value of the first digital signal is in a preset range, the scaling factor is equal to 1; if the voltage value of the first digital signal is greater than a maximum value of the preset range, the scaling factor is a positive number less than 1; and if the voltage value of the first digital signal is less than a minimum value of the preset range, the scaling factor is a positive number less than 1, wherein the preset range is a range of a voltage value of a digital signal obtained after analog-to-digital conversion is performed on an analog signal in a normal input range of the analog-to-digital converter; and the processing module is further configured to: determine, according to a principle that a product of the third scaling factor and a fourth scaling factor is 1, the fourth scaling factor corresponding to the third scaling factor; and a second gain module, configured to scale the first digital signal according to a second scaling factor, to obtain the scaled first digital signal, and configured to scale the second digital signal according to the fourth scaling factor obtained by the processing module, to obtain the scaled second digital signal, wherein a product of the first scaling factor and the second scaling factor is 1.