US 7,321,225 B2
Voltage reference generator circuit using low-beta effect of a CMOS bipolar transistor
Akhil K. Garlapati, Boston, Mass. (US); Bruce P. Del Signore, Hollis, N.H. (US); and David Pietruszynski, Austin, Tex. (US)
Assigned to Silicon Laboratories Inc., Austin, Tex. (US)
Filed on Mar. 31, 2004, as Appl. No. 10/813,837.
Prior Publication US 2005/0218879 A1, Oct. 06, 2005
Int. Cl. G05F 3/16 (2006.01)
U.S. Cl. 323—313  [323/316; 327/540] 43 Claims
OG exemplary drawing
 
1. A voltage reference generator comprising:
a first bipolar transistor configured to amplify a base current of the first bipolar transistor, the base current being proportional to an absolute temperature,
a resistor coupled to the base of the first bipolar transistor,
the base current being proportional to a voltage difference between two base-emitter voltages of bipolar transistors configured to have different current densities, the voltage difference being formed across the resistor coupled to the base and the base current being at least partially based on a resistance of the resistor coupled to the base, and
a current mirror circuit configured to mirror a first current at least partially based on the amplified base current and configured to provide the mirrored current to a voltage reference node.