Patent ID: 9601050
Date: 2017-03-21
CPC Classifications: G09G,H03F

Claim:
1. An external compensation sensing circuit including a fully differential operational amplifier, a first capacitor, a second capacitor and an outputting circuit for amplifying an induced current; a negative input terminal of the fully differential operational amplifier is connected to a display screen, a positive input terminal of the fully differential operational amplifier is connected to a reference voltage, a negative output terminal of the fully differential operational amplifier is connected to a first control terminal of the outputting circuit, and a positive output terminal of the fully differential operational amplifier is connected to a second control terminal of the outputting circuit; two terminals of the first capacitor are connected to the negative input terminal of the fully differential operational amplifier and an input terminal of the outputting circuit, respectively; one terminal of the second capacitor is connected to an output terminal of the outputting circuit, and the other terminal of the second capacitor is grounded, wherein a first switch is disposed between the negative input terminal of the fully differential operational amplifier and the display screen, a second switch is disposed between the two terminals of the first capacitor, and a third switch is disposed between the second capacitor and the output terminal of the outputting circuit, and wherein the outputting circuit includes a first outputting circuit and a second outputting circuit, and the output current of the second outputting circuit is M times of the output current of the first outputting circuit, where M is greater than 1 and less than 100.