CN103592985A

CN103592985A - Negative voltage regulation circuit

Info

Publication number: CN103592985A
Application number: CN201310555704.0A
Authority: CN
Inventors: 金建明; 王楠
Original assignee: WUXI PUYA SEMICONDUCTOR CO Ltd
Current assignee: WUXI PUYA SEMICONDUCTOR CO Ltd
Priority date: 2013-11-11
Filing date: 2013-11-11
Publication date: 2014-02-19

Abstract

The invention relates to the technical field of analog power sources, in particular to a negative voltage regulation circuit. By means of the negative voltage regulation circuit, negative voltage can be regulated conveniently, the accuracy of the circuit is improved, the area and current consumption of the circuit are saved, and cost is lowered. The negative voltage regulation circuit comprises a voltage comparator and a charge pump, and is characterized in that reference voltage Vref is connected with one end of a divider resistor R1, the other end of the divider resistor R1 is respectively connected with the in-phase input end of the voltage comparator and one end of a divider resistor R2, the output end of the voltage comparator is connected with the input end of the charge pump, the output end of the charge pump is respectively connected with circuit output voltage Vout, one end of a load resistor R3 and the other end of the divider resistor R2, and the reverse input end of the voltage comparator and the other end of the load resistor R3 are respectively connected to the GND.

Description

A kind of negative voltage Circuit tuning

Technical field

The present invention relates to analog power technical field, be specially a kind of negative voltage Circuit tuning.

Background technology

Conventionally in circuit, more common reference voltage is positive voltage signal, therefore need to adjust the output negative voltage of a negative voltage charge pump, first to be positive voltage value output negative voltage transition, this positive voltage value compares with reference voltage again, whether comparative result works in order to control charge pump, as shown in Figure 1, voltage comparator 1 in-phase input end connects reference voltage Vref, output terminal connects charge pump 2 input ends, the output terminal of charge pump 2 connects output voltage V out, output voltage V out connects by become a full member pressure device 3 of negative pressure the reverse input end that connects again voltage comparator 1 after divider resistances, sort circuit structure is on the one hand become a full member in pressure process and can be introduced error carrying out negative pressure, also can increase on the other hand current drain and increasing circuit area, additionally increased circuit cost.

Summary of the invention

In order to address the above problem, the invention provides a kind of negative voltage Circuit tuning, it can realize negative voltage adjustment easily, when improving circuit precision, saves again circuit area and current drain, reduces costs.

Its technical scheme is such: a kind of negative voltage Circuit tuning, it comprises voltage comparator and charge pump, it is characterized in that, reference voltage Vref connects divider resistance R1 one end, the divider resistance R1 other end connects respectively in-phase input end and divider resistance R2 one end of voltage comparator, the output terminal of described voltage comparator connects the input end of charge pump, described electric charge delivery side of pump is connecting circuit output voltage V out respectively, pull-up resistor R3 one end and the divider resistance R2 other end, the reverse input end of described voltage comparator and the pull-up resistor R3 other end be ground connection GND respectively.

It is further characterized in that, between described reference voltage Vref and the in-phase input end of described voltage comparator, a plurality of described divider resistances are set respectively between the in-phase input end of described voltage comparator and described electric charge delivery side of pump.

Adopt after structure of the present invention, reference voltage Vref connects divider resistance R1 one end, the divider resistance R1 other end connects respectively in-phase input end and divider resistance R2 one end of voltage comparator, the output terminal of voltage comparator connects the input end of charge pump, electric charge delivery side of pump is connecting circuit output voltage V out respectively, pull-up resistor R3 one end and the divider resistance R2 other end, the reverse input end of voltage comparator and the pull-up resistor R3 other end be ground connection GND respectively, saved the negative pressure of the prior art pressure device of becoming a full member, circuit area and current drain have been saved, reduce costs, realize easily negative voltage adjustment, improve circuit precision.

Accompanying drawing explanation

Fig. 1 is prior art circuits figure;

Fig. 2 is circuit diagram of the present invention.

Embodiment

As shown in Figure 2, a kind of negative voltage Circuit tuning, it comprises voltage comparator 1 and charge pump 2, reference voltage Vref connects divider resistance R1 one end, the divider resistance R1 other end connects respectively in-phase input end and divider resistance R2 one end of voltage comparator 1, the output terminal of voltage comparator 1 connects the input end of charge pump 2, the output terminal of charge pump 2 is connecting circuit output voltage V out, pull-up resistor R3 one end and the divider resistance R2 other end respectively, and the reverse input end of voltage comparator 1 and the pull-up resistor R3 other end be ground connection GND respectively; Between the in-phase input end of reference voltage Vref and voltage comparator 1, a plurality of divider resistances are set respectively between the in-phase input end of voltage comparator 1 and the output terminal of charge pump 2;

Its principle of work is as described below: reference voltage Vref is carried out dividing potential drop by divider resistance R1 and divider resistance R2, obtain the branch pressure voltage Vfbk on divider resistance R1, from the in-phase input end input of voltage comparator 1, compare with reverse input end, due to reverse input end ground connection GND, voltage comparator by after export an enable voltage Enable, enable voltage Enable controls charge pump 2 work, and the output terminal of charge pump 2 obtains circuit output voltage Vout.When | when Vout| is less than target voltage values, branch pressure voltage Vfbk is greater than the voltage at the GND place, ground of inverting input, and the enable signal Enable of the output terminal of voltage comparator 1 is effective, and charge pump works on, and makes | and the value of Vout| raises; When | when the value of Vout| is greater than or equal to target voltage values, the value of branch pressure voltage Vfbk is negative value or 0, the voltage of in-phase input end is less than or equal to the voltage of inverting input, the enable signal Enable of the output terminal of voltage comparator 1 is invalid, charge pump quits work, | the value of Vout| reduces gradually under the effect of pull-up resistor R3, when | when Vout| is less than target voltage values, charge pump is resumed work.Circuit output voltage Vout maintains near target voltage values like this, and the theoretical calculation formula of circuit output voltage Vout is: Vout=﹣ (R2/R1) * Vref.

Between the in-phase input end of reference voltage Vref and voltage comparator 1, between the in-phase input end of voltage comparator 1 and the output terminal of charge pump 2, a plurality of divider resistances are set respectively, as divider resistance R11, R12, R13 being set between reference voltage Vref and the in-phase input end of voltage comparator 1.。。R1n, can arrange divider resistance R21, R22, R23 between the in-phase input end of voltage comparator 1 and the output terminal of charge pump 2.。。R2n, the theoretical calculation formula of circuit output voltage Vout is: Vout=﹣ [(R21+R22+R23+.。。+R2n）/(R11+R12+R13+。。。+R1n)?]*Vref。

Claims

1. a negative voltage Circuit tuning, it comprises voltage comparator and charge pump, it is characterized in that, reference voltage Vref connects divider resistance R1 one end, the divider resistance R1 other end connects respectively in-phase input end and divider resistance R2 one end of voltage comparator, the output terminal of described voltage comparator connects the input end of charge pump, described electric charge delivery side of pump is connecting circuit output voltage V out, pull-up resistor R3 one end and the divider resistance R2 other end respectively, and the reverse input end of described voltage comparator and the pull-up resistor R3 other end be ground connection GND respectively.

2. a kind of negative voltage Circuit tuning according to claim 1, it is characterized in that, between described reference voltage Vref and the in-phase input end of described voltage comparator, a plurality of described divider resistances are set respectively between the in-phase input end of described voltage comparator and described electric charge delivery side of pump.