Capacitance-to-voltage modulation circuit

    公开(公告)号:US10353511B2

    公开(公告)日:2019-07-16

    申请号:US15271131

    申请日:2016-09-20

    Abstract: The present disclosure describes aspects of a capacitance-to-voltage modulation circuit. In some aspects, the circuit is used in touch sensing. In some aspects, a modulation circuit comprises a first pair of switches having one switch connected between a voltage source and a capacitor, and another switch connected between ground and the input of the circuit. The circuit also includes a second pair of switches having one switch connected between the voltage source and the input of the circuit, and another switch connected between ground and the capacitor. A third pair of the circuit's switches comprise one switch connected between the capacitor and an input of an analog-to-digital converter (ADC) and another switch connected between the input of the circuit and the input of the ADC. The third pair of switches may enable charge sharing of signals modulated by the first and second pairs of switches, a result of which can be used to sense touch input based on capacitance at the input of the circuit.

    PRECISION BANDGAP REFERENCE
    7.
    发明申请
    PRECISION BANDGAP REFERENCE 审中-公开
    精密贴带参考

    公开(公告)号:US20160266598A1

    公开(公告)日:2016-09-15

    申请号:US14643981

    申请日:2015-03-10

    CPC classification number: G05F3/267 G05F3/30

    Abstract: Systems and methods for producing reference voltages are disclosed. An example bandgap reference circuit includes a core bandgap module that produces a bias control for biasing the gate of a transistor to produce a proportional to absolute temperature current. The core bandgap module may use an operational amplifier that uses auto-calibration to reduce its input offset voltage. A trimming module uses the bias control to produce a proportional to absolute temperature current that is combined with a trim current and supplied to a resistor and diode to produce a trimmed bandgap voltage. The trimmed bandgap voltage is buffered to produce a reference voltage output. The trim current may be set based on a room temperature measurement of the reference voltage output.

    Abstract translation: 公开了用于产生参考电压的系统和方法。 一个示例性带隙基准电路包括一个核心带隙模块,其产生用于偏置晶体管栅极以产生与绝对温度电流成比例的偏置控制。 核心带隙模块可以使用使用自动校准的运算放大器来减少其输入失调电压。 修整模块使用偏置控制来产生与绝缘温度电流成比例的结合微调电流并提供给电阻和二极管以产生修整的带隙电压。 修整的带隙电压被缓冲以产生参考电压输出。 可以基于参考电压输出的室温测量来设置微调电流。

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