Bandgap reference voltage source

Abstract

The invention discloses a bandgap reference voltage source, which comprises a startup circuit, a proportional to absolute temperature (PTAT) current generating circuit and a reference voltage generating circuit. The startup circuit comprises an impulse generating unit, a p-channel metal oxide semiconductor (PMOS) pipe MP1, a PMOS pipe Mp6, an n-channel metal oxide semiconductor (NMOS) pipe MN1, an NMOS pipe MN2, a resistor R3 and a capacitor C1. The startup circuit adopts a digital circuit and a switch capacitor for startup so as to reduce area, save area of a board and lower cost. In a PTAT current generating circuit, no calculation amplifier is utilized so that the area of the board is saved and power consumption is lowered. Meanwhile, an overshoot release circuit is introduced to ensure input voltage can change in a wide range so that stability of reference output in a large power supply range can be ensured. Further, stability of a whole chip system is guaranteed. The release circuit is very simple and does not increase the area and the power consumption of the board.

Description

technical field [0001] The invention belongs to the technical field of power supplies, and in particular relates to the design of a bandgap reference voltage source. Background technique [0002] As an essential part of the integrated circuit, the reference provides bias current and reference voltage for the entire chip. The magnitude of the bias current determines the power consumption of the entire chip. At the same time, the error amplifier and comparator in the chip usually use the reference voltage as the reference voltage. The stability of the reference largely determines the realization of chip functions and performance. . [0003] The most common references used in integrated circuits are triode-based bandgap references. Such as figure 1 As shown, it is clamped by the error amplifier, and then a current proportional to the absolute temperature (Proportional to Absolute Temperature, PTAT) is generated through Q1, Q2 and R1. The PTAT current acts on R2, and the ban...

AI Technical Summary

Problems solved by technology

However, the start-up circuit often occupies a relatively large chip area

At the same time, when the power supply voltage changes within a relatively large range, especially when the power supply voltage is very high, a large overshoot will be generated at the reference output terminal at the moment of startup, which seriously affects the performance and stability of the system.

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