CURRENT DETECTION CIRCUIT

摘要

To provide a current detection circuit which suppresses a change in characteristics of a PMOS transistor on the non-inversion input terminal side of a differential amplifier due to NBTI and causes no change in threshold value at which an output voltage of the current detection circuit is inverted. A voltage limiting circuit which limits a voltage drop is provided between a non-inversion input terminal of a differential amplifier and a source of a PMOS transistor on the inversion input terminal side.

主权项

1. A current detection circuit comprising:
a sense resistor provided in a power supply line; and a differential amplifier which detects a current flowing through the power supply line by a voltage across the sense resistor, wherein the sense resistor is connected to an inversion input terminal and a non-inversion input terminal of the differential amplifier at both ends, wherein the differential amplifier includes a first resistor, a first PMOS transistor, and a first current source which are connected in series between the inversion input terminal and GND, wherein the differential amplifier includes a second resistor, a second PMOS transistor, and a second current source which are connected in series between the non-inversion input terminal and GND, wherein the first PMOS transistor has a gate and a drain connected to a gate of the second PMOS transistor, wherein the second PMOS transistor has a drain connected to an output terminal of the differential amplifier, and wherein a voltage limiting circuit which limits a voltage drop is provided between the non-inversion input terminal and a source of the first PMOS transistor.