发明名称 |
High signal to noise ratio capacitive sensing analog front-end |
摘要 |
Capacitance sensing circuits and methods are provided. The capacitance sensing circuit includes a capacitance-to-voltage converter configured to receive a signal from a capacitance to be sensed and to provide an output signal representative of the capacitance, an output chopper configured to convert the output signal of the capacitance-to-voltage converter to a sensed voltage representative of the capacitance to be sensed, an analog accumulator configured to accumulate sensed voltages during an accumulation period of NA sensing cycles and to provide an accumulated analog value, an amplifier configured to amplify the accumulated analog value, and an analog-to-digital converter configured to convert the amplified accumulated analog value to a digital value representative of the capacitance to be sensed. The analog accumulator may include a low pass filter having a frequency response to filter wideband noise. |
申请公布号 |
US9128573(B2) |
申请公布日期 |
2015.09.08 |
申请号 |
US201213619328 |
申请日期 |
2012.09.14 |
申请人 |
STMicroelectronics S.r.l.;;STMicroelectronics Asia Pacific Pte Ltd |
发明人 |
Angelini Paolo;Tripoli Giovanni Carlo;Lasalandra Ernesto;Ungaretti Tommaso;Tan Kien Beng;Guedon Yannick;Guo Dianbo;Tan Sze-Kwang |
分类号 |
G06F3/044 |
主分类号 |
G06F3/044 |
代理机构 |
Gardere Wynne Sewell LLP |
代理人 |
Gardere Wynne Sewell LLP |
主权项 |
1. A capacitance sensing circuit comprising:
a capacitance-to-voltage converter configured to receive a signal from a capacitance to be sensed and to provide an output signal representative of the capacitance; an output chopper configured to convert the output signal of the capacitance-to-voltage converter to a sensed voltage representative of the capacitance to be sensed; an analog accumulator configured to accumulate sensed voltages during an accumulation period of a number of sensing cycles and to provide an accumulated analog value; an amplifier configured to amplify the accumulated analog value; and an analog-to-digital converter configured to convert the amplified accumulated analog value to a digital value representative of the capacitance to be sensed. |
地址 |
Agrate Brianza (MB) IT |