POWER SUPPLY CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a power supply circuit, capable of supplying a stable internal voltage. SOLUTION: A power supply circuit 10 includes a reference voltage generation circuit 11 and an internal voltage generation circuit 13. The reference voltage circuit 11 has a first NMOSFET and a resistor R1 connected at its one end 105 with a power terminal Vcc and at the other end 107 to a drain electrode 19 of the FET. The internal voltage circuit 13 has a second NMOSFET connected at its gate electrode 25 with the drain electrode 19 of the first FET and at its source electrode 27 with a grounding terminal Vss, and also has a constant-voltage generation circuit 31 connected between a drain electrode 29 of the second FET and the power terminal Vcc for outputting a constant voltage. In this case, the gate length of the first FET is formed to be longer than that of the second FET.