Band-gap voltage reference circuit with low-power consumption and high electric power rejection ratio

Abstract

A band gap voltage reference circuit (1) comprises a band gap unit (5) and an operational amplifier (6). The band gap unit (5) comprises a first transistor (T1) and a second transistor (T2) which are arranged to produce a calibration PTAT voltage. The calibration PTAT voltage is in direction proportion to the voltage difference of base electrode-emitting electrode of the first transistor and the second transistor and is formed at the two ends of two main resistors (R2 and R5). The operational amplifier comprises a third transistor (T3), a fourth transistor (T4) and an automatic biasing current mirror circuit (7) which supplies current (8 to 10) to the collectors of the third transistor (T3) and the fourth transistor (T4). The base electrode-emitting electrode voltage of the first transistor (T1) is overlapped with the voltage secondary resistors (R1 and Rx) so as to provide the voltage reference between an output end (4) and a grounding terminal (3). A current branch circuit (10) is added to improve the power rejection ratio of the circuit.

Description

technical field [0001] The invention relates to a bandgap reference source circuit for low power consumption and high power supply rejection ratio, which is suitable for manufacturing by BiCMOS technology. The invention also relates to a method for generating a high power supply rejection ratio reference voltage source. Background technique [0002] Due to its low temperature coefficient, the bandgap reference source is widely used in various analog and mixed-signal circuit systems. For example, it is indispensable to integrate an on-chip voltage reference source in a power management chip. In order to prolong the service life of lithium batteries in portable electronic products, the requirements for product standby power consumption are getting higher and higher. As the power supply core of portable electronic products, power management chips have increasingly stringent requirements on their own standby power consumption. When the product is in standby, the on-chip voltag...

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Problems solved by technology

[0003] In the BiCMOS process, the Early voltage of the bipolar transistor is small, generally around 30V, so its small-signal collector-emitter resistance is not large, so it cannot achieve a high open-loop gain of the amplifier

Currently, bandgap reference sources used in various analog and mixed-signal circuit systems generally use a single-stage amplifier Cascode structure to achieve high output resistance, but the Cascode structure will consume a certain voltage margin, thereby increasing the minimum power supply voltage, and Cascode structure requires additional biasing circuitry, which increases the static power consumption of the voltage reference

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