Patent ID: 7236042

Claim:
A fuse trimming circuit, comprising: a CMOS input circuit connected across a power line and a ground line, and having an input terminal; a fuse resistor connected between said input terminal of the CMOS input circuit and the ground line; a trimming pad adapted for supplying voltage or current to said fuse resistor and said input terminal of the CMOS input circuit; a MOS transistor, connected across the power line and said input terminal, for pulling up the level at said input terminal in a state after said fuse resistor has been blown; and a switching transistor connected between said trimming pad and said input terminal, wherein said switching transistor is controlled to be turned on at a time of trimming, wherein said switching transistor comprises a switching MOS transistor, whose source is connected to the trimming pad, whose drain is connected to the input terminal, and wherein said switching MOS transistor comprises a P-channel MOS transistor, its gate being connected to a control pad and via a resistor to the power line, with its back gate being connected to the power line.