CN-119851625-B - Positive and negative pressure source driving circuit

CN119851625BCN 119851625 BCN119851625 BCN 119851625BCN-119851625-B

Abstract

The application discloses a positive and negative voltage source driving circuit which is used for providing stable and accurate positive and negative voltages for a load circuit and saving the area of a chip and the energy consumption during working. The voltage regulator is characterized by comprising a band gap reference circuit, a reference voltage generating circuit, a positive voltage operational amplifier and a negative voltage operational amplifier, wherein the band gap reference circuit works between a positive voltage VSP and a ground potential GND and is used for providing a positive reference voltage +VREF, the reference voltage generating circuit is used for receiving the positive reference voltage +VREF and outputting a positive reference voltage VREF_VGMP to the positive voltage operational amplifier and outputting a negative reference voltage VREF_VGMN to the negative voltage operational amplifier, and the positive voltage operational amplifier and the negative voltage operational amplifier respectively output a positive voltage and a negative voltage to the load circuit.

Inventors

QIU XIANGYI
XIE PEISHAN

Assignees

南宁初芯集成电路设计有限公司

Dates

Publication Date: 20260512
Application Date: 20250218

Claims (6)

1. A positive and negative voltage source driving circuit, comprising: The band-gap reference circuit works between the positive voltage VSP and the ground potential GND and is used for providing a positive reference voltage +VREF; A reference voltage generating circuit operating between the positive voltage VSP and the negative voltage VSN for receiving the positive reference voltage +VREF and outputting a positive reference voltage VREF_VGMP to the positive operational amplifier and a negative reference voltage VREF_VGMN to the negative operational amplifier, and The positive pressure operational amplifier and the negative pressure operational amplifier respectively output positive voltage and negative voltage to a load circuit; The reference voltage generating circuit further comprises a first multiplexer and a second multiplexer, the first multiplexer works between the positive voltage VSP and the ground potential GND, the second multiplexer works between the ground potential GND and the negative voltage VSN, the reference voltage generating circuit is used for receiving the positive reference voltage +VREF to respectively generate a plurality of different first voltages and a plurality of different second voltages to the first multiplexer and the second multiplexer, the first multiplexer selectively outputs the positive reference voltage VREF_VGMP to the positive operational amplifier from the plurality of different first voltages, and the second multiplexer selectively outputs the negative reference voltage VREF_VGMN to the negative operational amplifier from the plurality of different second voltages.
2. The positive and negative voltage source driving circuit according to claim 1, wherein the plurality of first voltages are respectively located between the positive voltage VSP and the ground potential GND, and wherein the plurality of second voltages are respectively located between the ground potential GND and the negative voltage VSN.
3. The positive and negative voltage source driving circuit according to claim 1, wherein the reference voltage generating circuit further comprises an operational amplifier having a first input terminal for receiving the positive reference voltage +VREF, a transistor having a gate connected to an output terminal of the operational amplifier and a source connected to a second input terminal of the operational amplifier and a first terminal of a first resistor string, the first resistor string comprising a plurality of first resistors connected in series, the second terminals of the plurality of first resistors outputting the plurality of different first voltages, respectively, a current mirror operating between the positive voltage VSP and the negative voltage VSN, the current mirror connected to a drain of the transistor and the second terminal of the second resistor string, the first terminal of the second resistor string and the first terminal of the first resistor string connected to the ground potential GND, the second resistor string comprising a plurality of second resistors connected in series, the second terminals of the plurality of second resistors outputting the plurality of different second voltages, respectively.
4. The positive and negative voltage source driving circuit according to claim 3, wherein said current mirror is a four transistor current mirror.
5. The positive and negative voltage source driving circuit according to claim 1, wherein the positive voltage VSP is between 5v and 6 v.
6. A positive and negative voltage source driving circuit according to claim 2 or 3, wherein the negative voltage VSN is between-5V and-6V.

Description

Positive and negative pressure source driving circuit Technical Field The application belongs to the field of positive and negative voltage reference voltage generating circuits, and relates to the design of a positive and negative voltage source electrode driving circuit of a liquid crystal display. Background Liquid crystal displays are one of the common output devices in modern electronic systems. A liquid crystal display includes a plurality of liquid crystal cells. The trans-voltage is applied to each liquid crystal unit, so that the light transmission degree of the liquid crystal unit can be controlled, and different gray scales can be displayed. By controlling the gray-scale settings of the three primary colors, respectively, the color of each pixel can be controlled. In order to control the voltage across a liquid crystal cell or other load circuit, a positive and negative voltage source drive circuit is required. In order to save power consumption and cost, a design with a smaller chip area is needed. The power consumed by the positive and negative pressure source driving circuit can be saved in addition to the cost saving. Disclosure of Invention The application provides a reference voltage generating circuit, a positive and negative voltage source driving circuit using the reference voltage generating circuit and a liquid crystal display, which aim to provide stable and accurate positive and negative voltages for a load circuit, save the area of a chip and the energy consumption during working, increase the competitiveness of the product and promote the environmental protection. In order to achieve the above purpose, the present application adopts the following technical scheme: According to an embodiment of the application, a reference voltage generating circuit is provided, which is characterized by comprising an operational amplifier, a transistor, a first resistor string, a current mirror, a second resistor string and a second resistor string, wherein the first input end of the operational amplifier is used for receiving positive reference voltage +VREF, the gate electrode of the transistor is connected to the output end of the operational amplifier, the source electrode of the transistor is connected to the second input end of the operational amplifier and the first end of the first resistor string, the first resistor string comprises a plurality of first resistors connected in series, the second ends of the first resistors respectively output a plurality of different first voltages, the current mirror is operated between a positive voltage VSP and a negative voltage VSN, the current mirror is connected to the drain electrode of the transistor and the second end of the second resistor string, and the second resistor string comprises a plurality of second resistors connected in series, the second ends of the second resistors respectively output a plurality of different second voltages, and the first ends of the second resistor string and the second ends of the first resistor string are connected to a ground potential GND. Furthermore, in order to provide positive and negative voltages simultaneously, the plurality of different first voltages are respectively located between the positive voltage VSP and the ground potential GND, and the plurality of different first voltages are respectively located between the ground potential GND and the negative voltage VSN. Furthermore, in order to select one of the positive voltages and the negative voltages as the positive voltage reference voltage vref_vgmp and the negative voltage reference voltage vref_vgmn, the reference voltage generating circuit further comprises a first multiplexer and a second multiplexer, wherein the first multiplexer is used for receiving the plurality of different first voltages and selecting one of the plurality of different first voltages to output the positive voltage reference voltage vref_vgmp to the positive voltage operational amplifier, and the second multiplexer is used for receiving the plurality of different second voltages and selecting one of the plurality of different second voltages to output the negative voltage reference voltage vref_vgmn to the negative voltage operational amplifier. Furthermore, in order to obtain a temperature-stable reference power supply, the positive reference voltage +vref is derived from a bandgap reference circuit, which operates between the positive voltage VSP and the ground potential GND. Further, in order to output negative voltage better, the current mirror is a current mirror with four transistors. According to an embodiment of the application, a positive and negative voltage source driving circuit is provided, which is characterized by comprising a band gap reference circuit, a reference voltage generating circuit, a positive voltage operational amplifier and a negative voltage operational amplifier, wherein the band gap reference circuit works between a positive voltage VSP and