Methods and apparatus for sensing current through power semiconductor devices with reduced sensitivity to temperature and process variations

    公开(公告)号:US09742398B2

    公开(公告)日:2017-08-22

    申请号:US14994560

    申请日:2016-01-13

    CPC classification number: H03K17/6871 G01R31/00 H03K17/145 H03K2217/0027

    Abstract: Current sensing through a power semiconductor device with reduced sensitivity to temperature and process variations. An example arrangement includes a power switch coupled between a voltage input and an output voltage terminal supplying current to a load; a first isolation switch coupled between the voltage input and a first node; a comparator amplifier having a pair of differential inputs coupled to the first node and a second node outputting a voltage in response to the difference at the differential inputs; and a first current source coupled between a positive supply voltage and the first node to output a first current responsive to the voltage output from the comparator amplifier; wherein the first current is proportional to the current through the power switch and a ratio of the on resistance of the power switch and the on resistance of the first isolation switch. Methods and additional arrangements are also disclosed.

    METHODS AND APPARATUS FOR SENSING CURRENT THROUGH POWER SEMICONDUCTOR DEVICES WITH REDUCED SENSITIVITY TO TEMPERATURE AND PROCESS VARIATIONS

    公开(公告)号:US20170201251A1

    公开(公告)日:2017-07-13

    申请号:US14994560

    申请日:2016-01-13

    CPC classification number: H03K17/6871 G01R31/00 H03K17/145 H03K2217/0027

    Abstract: Current sensing through a power semiconductor device with reduced sensitivity to temperature and process variations. An example arrangement includes a power switch coupled between a voltage input and an output voltage terminal supplying current to a load; a first isolation switch coupled between the voltage input and a first node; a comparator amplifier having a pair of differential inputs coupled to the first node and a second node outputting a voltage in response to the difference at the differential inputs; and a first current source coupled between a positive supply voltage and the first node to output a first current responsive to the voltage output from the comparator amplifier; wherein the first current is proportional to the current through the power switch and a ratio of the on resistance of the power switch and the on resistance of the first isolation switch. Methods and additional arrangements are also disclosed.

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