Temperature-stable MOSFET reference voltage source

Punchthrough operation of a short-channel MOSFET device to obtain a temperature-stable output voltage is described. The MOSFET is operated as a two-terminal device with its gate, source and substrate connected to ground, and a variable current source connected to its drain. When the voltage that is developed at the drain of the device, Vr, exceeds punchthrough, the sensitivity of Vrto changes in ambient temperature, T, can be minimized at any chosen temperature, Tc, by selecting an appropriate current density, Jopt. For constant Jopt, a deviation of approximately 10 ppM/°C is predicted for Vrover the temperature range from 200 to 300°K. Experimentally, deviations as low as 1 ppM/°C have been measured over a 100°C temperature range.