A Low-Voltage CMOS Bandgap Reference

The well-controlled exponential I
_D
(V
_S
) characteristics of MOS transistors operating in weak inversion allows the realization of a very good bandgap reference compatible with CMOS technologies and operating with an input voltage as low as 1.3 V. Variations of less than 3 mV over more than 100
^o
C have been obtained on a few samples and are certainly within reach for each circuit with an adjustment. The temperature range can be further extended by improving the design.