Patent ID: 6465999
Filing Date: 2002-10-15
Classification: G05F

Abstract:
A current-limited switch comprising:a power MOSFET; a pilot circuit connected in parallel with the power MOSFET, a pilot MOSFET and a pilot resistor being connected in the pilot circuit; a reference circuit comprising a current source and current mirror circuitry, the current mirror circuitry comprising first and second parallel circuits, each parallel circuit comprising a current mirror MOSFET connected in parallel with a resistor, the first and second parallel circuits being connected in series; a difference amplifier having a first input terminal coupled to a point in the pilot circuit and a second terminal coupled to a point in the reference circuit, and having an output terminal coupled to a gate of the power MOSFET; a current mirror compensation circuit comprising a first bypass switch for forming a short around the first parallel circuit when a voltage at a terminal of the power MOSFET reaches a first level; and a body control circuit connected to the power MOSFET, the body control circuit operating to short the body of the power MOSFET to the source or the drain of the power MOSFET, depending on the relationship between the respective voltages at the source and the drain of the power MOSFET.