A compensation circuit for transistor threshold voltages in integrated circuits is described. The compensation circuit includes a transistor, current source, and gate reference voltage supply. The transistor is biased to provide a well bias voltage, or backgate voltage VBG, which is coupled to transistors...http://www.google.com.au/patents/US6556068?utm_source=gb-gplus-sharePatent US6556068 - Threshold voltage compensation circuits for low voltage and low power CMOS integrated circuits
