TEMPERATURE COMPENSATED REFERENCE CURRENT GENERATOR

摘要

PROBLEM TO BE SOLVED: To provide a temperature compensated reference current generator based upon the subtraction of two currents generated from current sources. SOLUTION: This reference current generator 15 biased between Vdd and Gnd is provided with two current sources 11, 12 for respectively generating 1st and 2nd currents I1, I2. The 2nd current is mirrored and subtracted from the 1st current on a node 17 to generate a main current (I=I1-I2). The temperature coefficient (TC=dI/dT) of the main current can be erased by the proper design of a current source parameter. The main current is applied to the drain of an FET device T11. Reference voltage Vref obtained from the common drain/ gate of the device T11 is applied to the gate of an output NFET device T12. The reference current directly led out from the main current based upon a proportional factor is outputted to the drain 14 of the device T12, thereby outputting a compeltely temperature-compensated reference current (dIref /dT=0).