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Temperature and Power Supply Insensitive Voltage Reference

IP.com Disclosure Number: IPCOM000087742D
Original Publication Date: 1977-Mar-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

Crauwels, GL: AUTHOR

Abstract

A temperature and power supply insensitive voltage reference circuit is disclosed. Its operation is based on two principles. First, a forward-biased emitter-base diode has a voltage temperature coefficient that is negative and constant within a particular fabrication process. The second principle is that Zener diodes with operating voltages greater than five volts have a positive voltage temperature coefficient that is constant within a particular process. The forward biased emitter-base diode and a Zener are placed in series, and the temperature coefficients are adjusted to be equal by a resistor divider network.

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Temperature and Power Supply Insensitive Voltage Reference

A temperature and power supply insensitive voltage reference circuit is disclosed. Its operation is based on two principles. First, a forward-biased emitter-base diode has a voltage temperature coefficient that is negative and constant within a particular fabrication process. The second principle is that Zener diodes with operating voltages greater than five volts have a positive voltage temperature coefficient that is constant within a particular process. The forward biased emitter-base diode and a Zener are placed in series, and the temperature coefficients are adjusted to be equal by a resistor divider network.

The figure shows the temperature and power supply insensitive voltage reference circuit which is connected between a positive voltage supply plus or minus V and ground. The transistor Q2 and resistor R5 are connected to provide a relatively constant current supply to the diode-connected transistor D1. Diode D1 is connected in parallel with the resistor divider network R1 and R2, the common node of which serves as the connecting point for the cathode of the Zener diode Z1. Zener diode Z1 is connected between the resistor divider and ground by the bias resistor R3. The transistor 01 is connected between the base of transistor Q2 and ground and has its base biased by resistor R3. The output reference voltage terminal is connected to the anode of the diode D1. The ratio of the resistors R1 to R2, in...