Patent ID: 6433529
Filing Date: 2002-08-13
Classification: G05F,Y10S

Abstract:
A circuit for generating an output voltage proportional to temperature with a required gradient, the circuit comprising:a first stage arranged to generate a first voltage which is proportional to temperature with a predetermined gradient, the first stage comprising: first and second bipolar transistors with different emitter areas having their emitters connected together and their bases connected across a bridge resistive element, wherein the collectors of the first and second bipolar transistors are connected to an internal supply line via respective matched resistive elements such that the voltage across the bridge resistive element is proportional to temperature; a differential amplifier having its inputs connected respectively to said collectors of the first and second bipolar transistors, and its output connected to stabilisation circuitry connected between first and second power supply rails and an internal supply line which cooperates with the differential amplifier to maintain a stable voltage on the internal supply line despite variations between the first and second power supply rails; and a second stage which comprises a gain circuit connected to receive the first voltage for altering the predetermined gradient to match the required gradient, the gain circuit having as its voltage supply said stable voltage on the internal supply line.