Patent ID: 9214852
Filing Date: 2015-12-15
Classification: G05F,H02M

Abstract:
1. A precharge method for a DC-DC boost converter comprising a current mirror circuit having a reference transistor and a power transistor, the method comprising: a) maintaining a reference current flowing through said reference transistor as substantially constant by comparing a voltage at a first node in a voltage clamping circuit against a reference voltage to generate an error voltage, and by controlling said reference transistor by said error voltage; b) maintaining, by said voltage clamping circuit, a drain-source voltage of said reference transistor and a drain-source voltage of said power transistor as substantially equal, wherein said voltage clamping circuit comprises a first transistor having a source directly connected to a drain of said reference transistor, and a drain directly connected to a sampling resistor at said first node; and c) obtaining a substantially constant mirror current by reflecting said reference current through said power transistor to operate as a precharging current of a precharge circuit, wherein said current mirror circuit comprises an inductor coupled between sources of said reference transistor and said power transistor.