CURRENT MEASURING CIRCUIT

摘要

A current measuring circuit (100; 200; 300) for providing a current flow signal indicative of current flow between a first terminal (102; 202; 302) and second terminal (104; 204; 304), comprising:
a main transistor having a main drain, a main source (105; 205) and a main gate (109; 209), wherein the main source (105; 205) and the main drain (109; 209) define a main source-drain path, the main drain (109; 209) is connected to the first terminal (102; 202; 302), the main source is connected to the second terminal (104; 204; 304) and the main gate is connected to a first control terminal (109; 209);a sense transistor having a sense drain, a sense source (107; 207) and a sense gate, wherein the sense source and the sense drain define a sense source-drain path, the sense drain is connected to the first terminal (102; 202; 302) and the sense gate is connected to the first control terminal (109; 209);a bypass switch (108; 208; 308) having:
a controllable conduction path connected in parallel with the sense drain-source path of the main transistor between the first and second terminals (102; 202; 302, 104; 204; 304); anda second control terminal (111; 211) for enabling or preventing a current flow through the controllable conduction path;an output amplifier (110; 210; 310) having:
an input connected to both the sense source of the sense transistor and the controllable conduction path of the bypass switch; andan output for providing the current flow signal; anda controller (118; 218; 318) configured to set, in accordance with the current flow signal, a first control signal for the first control terminal (109; 209) and a second control signal for the second control terminal (111; 211) in order to enable current flow through:
each of the respective drain-source paths of the main and sense transistors; orthe controllable conduction path of the bypass switch (108; 208; 308).

主权项

1. A current measuring circuit for providing a current flow signal indicative of current flow between a first terminal and second terminal, comprising:
a main transistor having a main drain, a main source and a main gate, wherein the main source and the main drain define a main source-drain path, the main drain is connected to the first terminal, the main source is connected to the second terminal and the main gate is connected to a first control terminal; a sense transistor having a sense drain, a sense source and a sense gate, wherein the sense source and the sense drain define a sense source-drain path, the sense drain is connected to the first terminal and the sense gate is connected to the first control terminal; a bypass switch having:
a controllable conduction path connected in parallel with the sense drain-source path of the main transistor between the first and second terminals; anda second control terminal for enabling or preventing a current flow through the controllable conduction path; an output amplifier having:
an input connected to both the sense source of the sense transistor and the controllable conduction path of the bypass switch; andan output for providing the current flow signal; and a controller configured to set, in accordance with the current flow signal, a first control signal for the first control terminal and a second control signal for the second control terminal in order to enable current flow through:
each of the respective drain-source paths of the main and sense transistors; orthe controllable conduction path of the bypass switch.