Voltage reference circuit with switch control characteristic

Abstract

The invention discloses a voltage reference circuit with a switch control characteristic. One end of a voltage reference output control switch is connected with the output end of a positive temperature coefficient current source circuit; the other end of the voltage reference output control switch is serially grounded through a resistor and a PN junction and serves as a voltage reference output end; the connection and the disconnection of the voltage reference output control switch are controlled by an external enable signal; a start control switch is connected between the start control end of the positive temperature coefficient current source circuit and a starting voltage; a start control circuit controls the connection and the disconnection of the start control switch according to the external enable signal and the voltage output by the voltage reference output end; the control of the voltage reference output end is preferable; a start voltage is connected when the voltage reference circuit is in a start state; and the start voltage is disconnected when the voltage reference is generated. The start control and the output control of the linear analogue voltage reference circuit can be realized through the same external enable signal, and programmable control of the voltage reference circuit can be realized when the external enable signal is programmable, so that the using efficiency of the voltage reference circuit is improved and the power consumption is reduced.

Description

technical field [0001] The invention relates to a power management integrated circuit, in particular to a voltage reference circuit with switch control characteristics. Background technique [0002] The most classic voltage reference circuit in power management integrated circuits is the bandgap voltage reference source. The principle of the bandgap reference voltage source is to use the base-emitter voltage V of the bipolar transistor (BJT) BE Negative temperature coefficient and equivalent thermal voltage V T The positive temperature coefficients cancel each other out for a zero-drift voltage reference. Traditional bandgap voltage reference source Vbg=V BE +kV T , consists of two parts, V BE is a negative temperature coefficient of about a 2mV / °C, and V T is a positive temperature coefficient of about 0.086mV / °C, V BE About 0.7V, plus k times (k is a natural number greater than 1) equivalent thermal voltage V T , V T It is also proportional to the base and emitter...

AI Technical Summary

Problems solved by technology

[0006] The traditional bandgap reference voltage source has been working since the start-up, and the output voltage reference Vref has always existed as the output voltage reference of other circuits, so it is not conducive to reducing the power consumption of the entire system

Especially in multi-power supply systems, when the system does not need a certain voltage reference at a certain time, the existence of the voltage reference will bring unnecessary power consumption and waste energy

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