CN-117348666-B - Linear voltage regulator circuit and power supply device

CN117348666BCN 117348666 BCN117348666 BCN 117348666BCN-117348666-B

Abstract

The application relates to the technical field of linear voltage stabilizer circuits, and discloses a linear voltage stabilizer circuit which is applied to a multi-power domain, wherein the multi-power domain comprises N power supplies, N is an integer larger than 1, the linear voltage stabilizer circuit comprises N power tube branches connected in parallel, each power tube branch comprises a transmission gate and a power tube connected in series, a source electrode of each power tube is connected with a power supply, a control circuit comprises N control signal output ends, each control signal output end is connected with a control end of one transmission gate, the N control signal output ends output control signals for selecting the power tubes, and the transmission gates of the N power tube branches receive the control signals output by the control circuit and conduct the selected power tubes according to the control signals. The linear voltage stabilizer circuit provided by the embodiment of the disclosure can prevent current generated in the power tube from flowing through the control circuit, so that the voltage difference between the input end and the output end in the control circuit is reduced. The application also discloses power supply equipment.

Inventors

ZHAO DONG
ZHU YONGCHENG
KANG QINMIAO

Assignees

紫光同芯微电子有限公司

Dates

Publication Date: 20260505
Application Date: 20231106

Claims (7)

1. A linear voltage regulator circuit is applied to a multi-power domain, wherein the multi-power domain comprises N power supplies, N is an integer greater than 1, and the linear voltage regulator circuit is characterized by comprising: n parallel power tube branches, wherein each power tube branch comprises a transmission gate and a power tube which are connected in series, and the source electrode of each power tube is connected with a power supply; The control circuit comprises N control signal output ends, wherein each control signal output end is connected with a control end of a transmission gate; the transmission gates of the N power tube branches receive control signals output by the control circuit and conduct the selected power tubes according to the control signals; The linear voltage stabilizer circuit further comprises an error amplifier and a negative feedback circuit, wherein the input ends of all transmission gates are connected in parallel with the output end of the error amplifier; The control circuit further comprises N power input ends and a voltage output end, wherein each power input end is connected with a power supply, the voltage output end is connected with the power end of the error amplifier and is used for providing power for the error amplifier, and the voltage output by the voltage output end is the power voltage connected with one power input end of the N power input ends; the negative input end of the error amplifier is connected with the reference voltage, and the positive input end of the error amplifier is connected with the output end of the negative feedback circuit.
2. The linear voltage regulator circuit of claim 1, wherein each transmission gate comprises a PMOS transistor, an NMOS transistor and an inverter, wherein a gate of the PMOS transistor is connected in parallel with an input terminal of the inverter as a control terminal of the transmission gate, a drain of the PMOS transistor is connected in parallel with a drain of the NMOS transistor as an input terminal of the transmission gate, a source of the PMOS transistor is connected in parallel with a source of the NMOS transistor as an output terminal of the transmission gate, and a gate of the NMOS transistor is connected with an output terminal of the inverter.
3. The linear voltage regulator circuit of claim 1, wherein the control circuit comprises: Each control branch comprises a branch signal input end, a branch power supply input end and a branch voltage output end, each branch signal input end is connected with a control signal output end of the control circuit, each branch power supply input end is used as a power supply input end, and all branch voltage output ends are connected in parallel and used as voltage output ends.
4. A linear voltage regulator circuit according to claim 3, wherein each control branch comprises: the switching tube, the drain electrode of the switching tube is used as the branch power supply input end, the grid electrode of the switching tube is used as the branch signal input end, and the source electrode of the switching tube is used as the branch voltage output end.
5. A linear voltage regulator circuit according to claim 3, wherein, The branch signal input end of the ith control branch in the control circuit and the control end of the transmission gate in the ith power tube branch are connected in parallel with the ith control signal output end of the control circuit, The power input end of the branch power supply of the ith control branch in the control circuit, the source electrode of the power tube in the ith power tube branch and the input end of the ith power supply in the control circuit are connected with the same power supply; Wherein i=1, N.
6. The linear voltage regulator circuit of claim 1, wherein the negative feedback circuit comprises: The output end of the first voltage dividing element is used as the output end of the negative feedback circuit; The input end of the second voltage dividing element is connected with the output end of the first voltage dividing element, and the output end of the second voltage dividing element is grounded.
7. A power supply device comprising N power supplies, N being an integer greater than 1, characterized in that the power supply device further comprises a linear voltage regulator circuit according to any one of claims 1 to 6.

Description

Linear voltage regulator circuit and power supply device Technical Field The present application relates to the technical field of linear voltage regulator circuits, and for example, to a linear voltage regulator circuit and a power supply device. Background In a power supply system, a linear regulator is generally required to provide a stable voltage source as a power supply voltage for circuits such as a digital circuit and a flash memory circuit. The linear voltage stabilizer (low dropout regulator, LDO) has the advantages of low cost, small area, small output noise, simple structure and the like, and has become an important circuit in a power management chip. The essence of the LDO is that a stable output voltage is obtained by the bias current and reference voltage generated by the bandgap reference and the negative feedback control loop, and the output voltage is basically unchanged with the process, temperature and supply voltage. In the application scenario of the power management chip, there are two or more power domains, such as a battery domain, a contact power domain, a non-contact power domain, etc., so that the power selection circuit is required to select the power source to be used as the power source voltage of the error amplifier of the LDO and the source voltage of the power tube according to the rule of the power management system. In the traditional power supply selection circuit, the multiple power supply domains are used as the power supply voltage of the power tube circuit of the linear voltage stabilizer through the power supply selection circuit. In the process of implementing the embodiments of the present disclosure, it is found that at least the following problems exist in the related art: In a power management chip, LDOs are generally used to supply power to a digital circuit, and as the scale of the digital circuit increases, the power consumption increases, and the current flowing through a power tube of the LDO increases, so that the current flowing through a switching tube of a power selection circuit increases gradually, which causes a problem that the voltage difference across the switching tube increases. It should be noted that the information disclosed in the above background section is only for enhancing understanding of the background of the application and thus may include information that does not form the prior art that is already known to those of ordinary skill in the art. Disclosure of Invention The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed embodiments. This summary is not an extensive overview, and is intended to neither identify key/critical elements nor delineate the scope of such embodiments, but is intended as a prelude to the more detailed description that follows. The embodiment of the disclosure provides a linear voltage stabilizer circuit and power supply equipment, which are used for reducing the voltage difference between an input end and an output end of a switching tube in a power supply selection circuit. In some embodiments, the linear voltage regulator circuit is applied to a multi-power domain, the multi-power domain comprises N power supplies, N is an integer larger than 1, and the linear voltage regulator circuit is characterized by comprising N power tube branches connected in parallel, each power tube branch comprises a transmission gate and a power tube connected in series, a source electrode of each power tube is connected with a power supply, a control circuit comprises N control signal output ends, each control signal output end is connected with a control end of one transmission gate, the N control signal output ends output control signals for selecting the power tubes, and the transmission gates of the N power tube branches receive the control signals output by the control circuit and conduct the selected power tubes according to the control signals. Optionally, the linear voltage stabilizer circuit further comprises an error amplifier and a negative feedback circuit, wherein the input ends of all the transmission gates are connected in parallel with the output end of the error amplifier, the output end of each transmission gate is connected with the grid electrode of one power tube, and the drain electrodes of all the power tubes are connected in parallel with the input end of the negative feedback circuit. Optionally, each transmission gate comprises a PMOS tube, an NMOS tube and an inverter, wherein the grid electrode of the PMOS tube is connected in parallel with the input end of the inverter and used as the control end of the transmission gate, the drain electrode of the PMOS tube is connected in parallel with the drain electrode of the NMOS tube and used as the input end of the transmission gate, the source electrode of the PMOS tube is connected in parallel with the source electrode of the NMOS tube and used as the output end of the transmission gate, and