Circuit and method for compensating for early effects

摘要

Early effects are intrinsically present in bipolar junction transistors (BJTs). Described are examples of complimentary to absolute temperature (CTAT) and proportional to absolute temperature (PTAT) cells that reduce errors associated with the Early effects that would otherwise be present.

主权项

1. A complimentary to absolute temperature, CTAT, cell, the cell comprising:
a first bipolar transistor having a collector, base and emitter, a CTAT voltage generator coupled to the collector of the first bipolar transistor to bias the collector with a CTAT voltage and compensate the first bipolar transistor for the Early effect; wherein the CTAT voltage generator comprises a second bipolar transistor of the cell, the second bipolar transistor coupled to the collector of the first bipolar transistor such that collector of the first bipolar transistor is biased with a voltage related to the base emitter voltage of the second bipolar transistor; and a current mirror, the current mirror mirroring a current generated by the second bipolar transistor across a resistor provided at the collector of the first bipolar transistor to bias the collector of the first bipolar transistor with the voltage related to the base emitter voltage of the second bipolar transistor.