| 摘要 |
PROBLEM TO BE SOLVED: To provide a constant voltage circuit for generating a constant voltage in proportion to a band gap voltage without impairing temperature characteristic at a power voltage lower than a band gap voltage. SOLUTION: The both edge voltages of a resistance R1 in proportion to temperature are transformed into currents I1 by PMOS transistors QP1 and QP2, and currents 14 having a prescribed ratioαto the current I1 are outputted by a PMOS transistor QP3, and a forward voltage VD1 of a diode D1 is transformed into currents I2 by an arithmetic amplifier OP2 and a PMOS transistor QP4, and currents I3 having a prescribed ratioβto the currents I2 are outputted from a PMOS transistor QP5 so that a constant voltage in proportion to a band gap voltage non-fluctuating against temperature change which is not more than the band gap voltage can be obtained, and the currents I4 are added to the currents I3, and transformed into a voltage by a resistance R3, and an output voltage Vo is generated.
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