Temperature compensated voltage reference for low and wide voltage ranges

Abstract

A reference voltage generator which compensates for temperature and V.sub.CC variations includes a constant current source and a MOS P-channel transistor. The constant current source provides a constant current over a wide range of V.sub.CC that corresponds to biasing a p-channel transistor in a region where its resistance is constant. The output of the current source is supplied to the P-channel transistor, which is in saturation. The constant current provides a constant voltage drop across the P-channel transistor. Hence, a stable reference voltage is generated. Temperature compensation is provided by biasing the P-channel transistor to saturation and supplying a constant current that the corresponds to biasing a p-channel transistor where the resistance is substantially constant over a temperature range. The current causes a voltage drop across the P-channel transistor to maintain a stable reference voltage. Also, temperature compensation is further provided by utilizing the negative temperature coefficients of the resistors included in the constant current source.

Dependencies are inferred from the claim text.