Patent ID: 7986499
Filing Date: 2011-07-26
Classification: G05F

Abstract:
1. A current limiting circuit for limiting a current passing through an output pass circuit of a voltage regulator, the current limiting circuit comprising: a current sampling circuit for sampling the current passing through the output pass circuit to obtain a duplicated current being proportional to the current passing through the output pass circuit, wherein the output pass circuit is a P-channel MOSFET MPass, the current sampling circuit is a P-channel MOSFET MP a current mirror circuit for producing a mirror current being proportional to the duplicated current with the duplicated current as a reference current; a current to voltage converter for producing a voltage being proportional to the mirror current, wherein the current to voltage converter is formed by a resistor connected between a gate terminal and a source terminal of a MOSFET, the voltage is being produced when the mirror current goes though the resistor; and a voltage comparator for comparing the voltage produced by the current to voltage converter with a threshold voltage and turning off the output pass circuit when the voltage produced by the current to voltage converter is larger than or equal to the threshold voltage, wherein the voltage comparator includes the MOSFET, wherein the voltage comparator is a P-channel MOSFET MP