| 摘要 |
PURPOSE:To set a constant current and a temperature coefficient of the temperature drift of said constant current independently from each other, by producing the voltage having an optional temperature coefficient at a route which feeds the change of the collector potential of a transistor through which a reference current flows back to the base of the transistor. CONSTITUTION:The change of the base potential of a transistor Tr21 is fed back to the base of the Tr21 as a change of the collector potential via a Tr23 and a resistance 28 to stabilize the base potential. Thus the collector potential of the Tr21 is stabilized together with the emitter potential of the Tr23 and the base potential of a Tr24. While a constant current I0 corresponding to a reference current flowing to the collector of the Tr21 is supplied to a collector electrode 32 of the Tr24 from a power supply 31 via a resistance 26. A current equal to a resistance 27 flows to a resistance 28 if the base current of each Tr is neglected. Then a current dependent on the voltage Vj flows to the resistance 27 since the both-end voltage of the resistance 27 is equal to the base- emitter voltage Vj of a Tr22. As a result, the voltage equal to a multiple of the voltage Vj is generated at both ends of the resistance 28. Thus it is possible to set the current I0 and a temperature coefficient of the temperature drift of the current I0 independently from each other. |
