A micromachined low-power temperature-regulated bandgap voltage reference

This paper describes a temperature regulated bandgap voltage reference fabricated in a foundry CMOS process. Using a simple post-processing micromachining step, a small portion of the chip containing the reference circuitry is thermally isolated from the rest of the silicon die. Having high thermal resistance and small thermal mass, the reference requires 200 times less power and warms up 160 times faster than previous heated-substrate circuits. The reference, in a standard CMOS process, can be included on-chip with CMOS data converters and mixed-signal products.