Bias current reference circuit
 A bias current reference circuit is disclosed having a diode-connected bipolar device connected in series with an MOS device to develop a reference voltage which is proportional to a bias current. The reference voltage is used by an MOS device connected in series with a resistor to develop a reference current which is proportional to the reference voltage. The reference current is used by a diode-connected MOS device to develop a bias voltage which is proportional to the reference current. The bias voltage in turn is used by another MOS device to develop the bias current in proportion to the bias voltage. The bias voltage is also used by other MOS devices to provide similar bias currents. In the disclosed embodiment, such a bias current is used by a complementary diode-connected MOS device to develop a complementary bias voltage. The complementary bias voltage may be used to develop start-up bias current in the event the bias current reference circuit fails to provide a suitable bias voltage. 
Motorola, Inc.
G
G05F
inventional
Roger A.
Whatley