A bandgap reference source circuit

Abstract

The invention relates to a band-gap reference circuit. The band-gap reference circuit comprises an eleventh transistor, a fifth transistor, a third transistor, a fourth transistor, a sixth transistor and an operational amplifier, wherein a diode connecting way is adopted by the third transistor and the fourth transistor, a part of a first operational amplifier loop circuit is formed by the third transistor and the fourth transistor, and the third transistor and the fourth transistor work in a sub-threshold region, so that the voltage difference of the third transistor and the fourth transistor is used as PTC (Positive Temperature Coefficient) voltage; the fourth transistor is connected with the fifth transistor, the fifth transistor is connected with the sixth transistor, the fifth transistor, the eleventh transistor and the operational amplifier are connected, and the diode connecting way is adopted by the sixth transistor; the sixth transistor works in the sub-threshold region, so that the voltage of the sixth transistor is used as NTC(Negative Temperature Coefficient) voltage, and further ZTC (Zero Temperature Coefficient) reference voltage can be further outputted by the band-gap reference circuit. The band-gap reference circuit disclosed by the invention can be applicable to the integrated circuit of a deep sub-micron technology.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to the technical field of power supplies in integrated circuits. Background technique [0002] With the rapid development of large-scale integrated circuits and the continuous updating of chip production processes, the chip power supply voltage needs to be continuously reduced to achieve low-power circuit design. Therefore, low voltage and low power consumption requirements are put forward for the internal functional modules of the chip. Many chips need to use a bandgap reference source to provide reference voltages for internal ADC (analog-to-digital converter), DAC (digital-to-analog converter), and SerDes (serializer deserializer) circuit modules. The minimum power supply voltage of the reference circuit is one of the limitations of the chip adopting a single power supply system, and the power supply suppression capability of the reference circuit also has a certain impact on ...

AI Technical Summary

Problems solved by technology

This voltage is difficult to meet the low-voltage, low-power requirements in modern deep submicron CMOS processes

Depend on figure 1 It can be seen that the reference voltage of the bandgap output is generated by the reference current on the resistor R3. This reference voltage generation circuit is not placed in the loop of the op amp OP1. Due to the short-channel modulation effect in the deep submicron process, the circuit’s Limited power supply rejection

At the same time, the circuit requires a unity gain buffer to have a certain resistive load capability

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