BICMOS CURRENT REFERENCE CIRCUIT

摘要

A BiCMOS current reference circuit includes a reference core, a startup circuit, and a reference current output circuit. The reference core contains a current mirror, a positive temperature coefficient current generator, and a negative temperature coefficient current generator. The current mirror generates matching branch current. The positive and negative temperature coefficient currents were added in certain proportion to generate a reference current with zero temperature coefficient at room temperature. The startup circuit starts the reference core at power-on. The reference current output circuit proportionably outputs reference current generated by the reference core. Compared with the conventional voltage reference, the circuit uses current conveying technique, so it won't be affected by DC voltage drops of power supply network, and it features low transmission loss, good matching, excellent temperature stability, small chip size and auto-startup at power-on. It's preferably suitable for applications where A/D and D/A converters require accurate reference signals.

主权项

1. A Bipolar Complementary Metal Oxide Semiconductor (BiCMOS) current reference circuit, comprising a startup circuit, a reference core circuit, and a reference current output circuit, wherein:
the startup circuit, for starting the reference core circuit at power on; the reference core circuit, for generating reference current with zero temperature coefficient at room temperature by canceling positive temperature coefficient current with negative temperature coefficient current; and the reference current output circuit, for proportionably outputting reference current generated by the reference core circuit.