Voltage independent symmetrical current source with cross-coupled transistors

摘要

A symmetrical current source 10 has a pnp current source 11 including four npn transistors Q1-Q4 and a pnp output transistor Q28 and an npn current sink 12 including pnp transistors Q5-Q8 and an output transistors Q29. In current source 11 cross coupled transistors Q3, Q4 establish a predetermined bias for source 11; cross coupled transistors Q7, Q8 establish a predtermined bias for sink 12.