公开(公告)号：US20160003663A1

公开(公告)日：2016-01-07

申请号：US14790355

申请日：2015-07-02

Applicant: Texas Instruments Incorporated

Inventor： Daniele Miatton ,  Athos Canclini ,  Dongtai Liu ,  Evgeny Fomin ,  George Reitsma ,  Riccardo Tarelli

IPC: G01F23/26

CPC classification number: G01F23/263 ,  G01F23/266 ,  G01F23/268

Abstract: Capacitive liquid level measurement uses differential out-of-phase (OoP) channel drive to counteract human body capacitance. In an example embodiment, a container assembly includes a capacitive sensor with symmetrical CHx and CHy capacitor electrodes, corresponding in height to a liquid level measurement range. A CHx driver provides a CHx excitation/drive to the CHx electrode, and a CHy driver provides OoP CHy excitation/drive to the CHy electrode that is substantially 180 degrees out-of-phase with the CHx drive. Capacitance associated with the liquid level is measured by acquiring capacitance measurements through the CHx channel (such as based on capacitive charge transfer), and converting the capacitance measurements to an analog voltage corresponding to liquid-level capacitance (which can then be converted to digital data). The capacitive sensor can be configured with SHLDx/SHLDy shields disposed behind, and driven in phase with, respective CHx/CHy electrodes.

Abstract translation: 电容液位测量使用差分异相（OoP）通道驱动来抵消人体电容。 在示例性实施例中，容器组件包括具有对称CHx和CHy电容器电极的电容传感器，其高度对应于液位测量范围。 CHx驱动器为CHx电极提供CHx激励/驱动，CHy驱动器向CHy驱动器提供OoP CHy激励/驱动，与CHx驱动器基本上为180度异相。 通过采用CHx通道（例如基于电容电荷转移）获取电容测量值，并将电容测量值转换为与液位电容相对应的模拟电压（然后将其转换为数字数据）来测量与液位相关的电容 ）。 电容传感器可以配置有SHLDx / SHLDy屏蔽，其布置在相应的CHx / CHy电极的后面并与其相驱动。