CURRENT SOURCE/SINK WITH HIGH OUTPUT IMPEDANCE USING BIPOLAR TRANSISTOR

摘要

PROBLEM TO BE SOLVED: To provide a circuit and method with which a cascode current source/sink with high output impedance can be realized. SOLUTION: The dependency on the external load is reduced by directing a compensation current corresponding to change in base current of the cascode (Q1) in an approach such that the compensation current cancels out the error of the cascode (Q1). A biasing circuit (200) is included and arranged such that change in base current of the cascode (Q1) is detected and a corresponding current is summed at the emitter of the cascode (Q1) such that the collector current of the cascode (Q1) remains unchanged. COPYRIGHT: (C)2005,JPO&NCIPI