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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