Asymmetric band-gap reference circuit

Abstract

The invention relates to an asymmetric band-gap reference circuit which is characterized by comprising a positive temperature coefficient current generation unit, a negative temperature coefficient current generation unit, a zero temperature coefficient reference voltage VREF generation unit, a switch tube control unit and a start circuit Start-up; and the asymmetric band-gap reference circuit has the advantages that: (1) a unilateral resistor R2 serves as a low-voltage bandgap reference circuit for temperature compensation; (2) the obtained bandgap reference voltage VREF has low-power supply voltage action, extremely low temperature drift and better power supply features; (3) the circuit can still work normally when the op amp as quite high offset voltage; and (4) the structure is simple, the operation is convenient, and the circuit can provide precise and stable reference voltage for any system.

Description

(1) Technical field: [0001] The invention relates to a reference voltage compensation circuit, in particular to an asymmetrical bandgap reference circuit. (two) background technology: [0002] In general systems, there are generally two types of bandgap reference circuits. (1) if Figure 1-a As shown, the common bandgap reference circuit has high start-up voltage and non-adjustable output voltage; (2) such as Figure 1-b As shown, the ordinary low-voltage bandgap reference circuit has a low start-up voltage, and the output voltage can be any value, and the above circuit will fail to start when there is a large offset voltage in the op amp, such as Figure 4 As shown, this will limit the yield of the chip. (3) Contents of the invention: [0003] The purpose of the present invention is to design a kind of asymmetric bandgap reference circuit, it can overcome the deficiencies in the prior art, make the obtained bandgap reference voltage except low power supply voltage actio...

AI Technical Summary

Problems solved by technology

(1) if Figure 1-a As shown, the common bandgap reference circuit has a high start-up voltage and an unadjustable output voltage; (2) such as Figure 1-b As shown, the ordinary low-voltage bandgap reference circuit has a low start-up voltage, and the output voltage can be any value, and the above circuit will fail to start when there is a large offset voltage in the op amp, such as Figure 4 As shown, this will limit the chip yield

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