发明名称 Current mirror self-capacitance measurement
摘要 In one embodiment, a method includes applying a first current to a capacitance of a touch sensor. The application of the first current to the capacitance for a first amount of time modifies the voltage at the capacitance from the reference voltage level to a first pre-determined voltage level. The method also includes applying a second current to an integration capacitor. The second current is proportional to the first current. The application of the second current to the integration capacitor for the first amount of time modifies the voltage at the integration capacitor from the reference voltage level to a first charging voltage level. The method also includes determining whether a touch input to the touch sensor has occurred based on the first charging voltage level.
申请公布号 US8754659(B2) 申请公布日期 2014.06.17
申请号 US201213445748 申请日期 2012.04.12
申请人 Atmel Corporation 发明人 Brunet Samuel;Hristov Luben Hristov;Pedersen Trond Jarle;Sharif Iqbal
分类号 G01R27/26 主分类号 G01R27/26
代理机构 Baker Botts LLP 代理人 Baker Botts LLP
主权项 1. A method comprising: applying a first current to a capacitance of a touch sensor, the first current having a first magnitude, the first magnitude being the magnitude of the current actually applied to the capacitance, the application of the first current to the capacitance for a first amount of time modifying a voltage at the capacitance from a reference voltage level to a first pre-determined voltage level; applying a second current to an integration capacitor, the second current being proportional to the first current, the application of the second current to the integration capacitor for the first amount of time modifying a voltage at the integration capacitor from the reference voltage level to a first charging voltage level; applying a third current to the capacitance, the application of the third current to the capacitance for a second amount of time modifying the voltage at the capacitance from the first pre-determined voltage level to the reference voltage level; applying a fourth current to the integration capacitor, the fourth current being proportional to the third current, the application of the fourth current to the integration capacitor for the second amount of time modifying the voltage at the integration capacitor from the first charging voltage level to a second charging voltage level; and determining whether a touch input to the touch sensor has occurred based on the second charging voltage level.
地址 San Jose CA US