| 摘要 |
A constant-voltage circuit which can be driven by a low voltage (lower than 1 V) of a nickel-cadmium battery, etc., and which provides a temperature-compensated stable voltage output. The constant-voltage circuit comprises battery 1, band-gap-type current-mirror-type constant-current source circuit 3 which outputs collector current IC9 of transistor Q9 with a positive temperature coefficient, current source circuit 5 which outputs collector current IC8 of transistor Q8 having a negative temperature coefficient and defined by base-emitter voltage VBEQ7 of transistor Q7, and a load resistor element R0. At node N0, collector current IC9 and collector current IC8 are added. The temperature coefficients of these two currents cancel each other. Consequently, the current at node N0 does not have temperature dependence. Load resistor element R0 converts this current to a voltage as the output voltage VOUT.
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