| 摘要 |
PURPOSE:To decrease the area occupied by an element deciding a reference current in circuit integration by using an ON-resistance of a unipolar transistor (TR) in order to decide the reference current of a constant current circuit. CONSTITUTION:A base and a collector of a TR T3 are connected, its common connecting point is connected to a base of a TR T4 and also connected to a drain of a P-channel MOS.FETTS. Further, a back gate and a source of the FETTS are connected and its common connecting point is connected to a power supply VCC. Each emitter of TRs T3, T4 is connected to common respectively. In giving a potential VC (VCC-VC>0) to a gate terminal G of the FETTS, a stable and highly accurate reference current I3 (=ISD) flows to the FETTS by using the FET at a saturated region depending on the relation between a source-drain current ISD and a drain-source potential VDS of the FETTS. As a result, the absorption current I4 has an error within + or -5% of the reference current I3 over a wide temperature range or current level.
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