| 摘要 |
A three terminal current source is disclosed including a current turn around circuit comprising first and second transistors. The emitters of the pair of transistors are coupled to a common terminal with the collector of the first one of the pair of the transistors being coupled to an input terminal at which is supplied a reference current with the collector of the other one of the pair of transistors being coupled in cascode through the emitter collector path of an output transistor to the output terminal of the current source circuit. The base electrodes of the pair of transistors are directly connected to each other with the control electrode of the output transistor being connected to the collector of the first one of the pair of transistors of the current turn around circuit. A single lateral split collector transistor is utilized to improve the current match between the input and output of the current source wherein the emitter of this transistor is connected to the base electrodes of the pair of transistors of the current source with one collector and the base of the split collector transistor being connected to the collector of the second one of the pair of transistors. The other one of the collectors of the split collector transistor is connected directly to the output terminal of the current source. The aforedescribed structure provides a current source having improved matching characteristics over a temperature range which varies from -40 DEG C. to +125 DEG C.
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