Current sense amplifier
AssigneeWill Semiconductor (Shanghai) Co. Ltd.
InventorHiroyuki Kimura
Life of this patent
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Abstract
A current sense amplifier measures a voltage drop in a drive transistor LS to measure the current flowing through the drive transistor LS. The current sense amplifier includes a preamplifier pre-amp, to which a voltage across the drive transistor LS is inputted, and which obtains a positive output and a negative output corresponding to a voltage difference of the inputted voltage across the drive transistor; and a switch sw, which connects the input end of a common mode voltage vcm and the negative output, the common mode voltage vcm serving as the operation reference of the preamplifier pre-amp. A change of the positive output caused by turning on/off the switch sw can be detected.
Claims4
A current sense amplifier, which measures a voltage drop in a drive transistor to measure a current flowing through the drive transistor, the current sense amplifier comprising:
- a preamplifier, to which a voltage across the drive transistor is inputted, and which obtains a positive output and a negative output corresponding to a voltage difference of the inputted voltage across the drive transistor;
- a post-amplifier, to which the positive output and the negative output of the preamplifier are inputted, and which obtains an output corresponding to a difference of the positive output and the negative output of the preamplifier;
- and
- a switch, which connects an input end of a common mode voltage and the negative output, the common mode voltage serving as the operation reference of the preamplifier;
- wherein a change of the positive output caused by turning on/off the switch is able to be detected as a change of the output of the post-amplifier.
Dependencies are inferred from the claim text.