Bidirectional current sensing circuit

A bidirectional current sensing circuit for sensing load current of an H-bridge circuit, wherein the H-bridge circuit comprises a first switch pair controlled by a first control signal and a second switch pair controlled by a second control signal, the H-bridge circuit is configured to drive a load by alternatively turning-ON and turning-OFF the first switch pair and the second switch pair, the bidirectional current sensing circuit comprising:

• a sensing resistor, having a first terminal coupled to the load, and a second terminal coupled to a reference ground;
• a first amplifier, having a non-inverting terminal coupled to the first terminal of the sensing resistor through a first resistor, an inverting terminal coupled to the second terminal of the sensing resistor through a second resistor, a clock input terminal coupled to the first control signal, and an output terminal, wherein the first amplifier is configured to operate in one of an output mode and a zeroing mode based on the first control signal;
• a second amplifier, having a non-inverting terminal coupled to the inverting terminal of the first amplifier, an inverting terminal coupled to the non-inverting terminal of the first amplifier, a clock input terminal coupled to the second control signal, and an output terminal, wherein the second amplifier is configured to operate in one of the output mode and the zeroing mode based on the second control signal;
• and
• an output transistor, having a first terminal coupled to an output circuit to provide a current sensing signal indicating the load current, a second terminal electrically connected to the inverting terminal one of the first and second amplifiers operating in the output mode, and a control terminal electrically connected to the output terminal of the one of the first and second amplifiers operating in the output mode.