Temperature compensated bias generator

摘要

A temperature compensated current source for driving a multi-vibrator (19) includes a voltage generator (10) that outputs a voltage that is proportional to absolute temperature (PTAT) and a resistor (12) for setting the current output by the voltage generator (10). The temperature coefficient of the resistor (12) is chosen such that any variations in the current supplied by the voltage generator (10) are compensated for to result in a current that has substantially no temperature variation. This current is mirrored to a current source (18) for driving the multi-vibrator (19). The voltage across the resistor (12) is a function of temperature, with the current being a function of the value of the resistor (12). The temperature coefficient of the resistor (12) is substantially equal to the temperature coefficient of the voltage generator (10) to yield a temperature coefficient of substantially 0 ppm/ DEG C. for the current.