A wide range temperature stable integrated current reference

Abstract

A current reference integrated circuit was built in a 2 micron CMOS process base on SIMOX technology, without the need of external trimming, to provide 19.5/spl mu/A. the overall error was less than +/-1% (< 67 ppm/k) over 240 K temperature range from -40 to 200 /spl deg/C (Vdd<5V, Vcc>10V), at a power consumption of less than 1.5 mW. From -15 to 90/spl deg/C the TC was < 12 ppm/K, derived by higher order temperature compensation. The temperature dependence of the diode parameters is cancelled out against the temperature coefficient of the resistors. The error of the absolute current value was +/-5% (30 circuits from two different wafers). The circuit of 0.3 mm/sup 2/ contains p-channel and n-channel MOS transistors, pin-diodes, and p+ resistors. It is applicable for oscillator and filter frequency stability, and for precise time delay circuits, especially in smart power and high temperature applications.