CN-122001190-A - High-side N-MOS driving circuit and driving method for switching power supply

CN122001190ACN 122001190 ACN122001190 ACN 122001190ACN-122001190-A

Abstract

The application relates to a high-side N-MOS driving circuit of a switching power supply and a driving method thereof, wherein the logic enhancement module and the level conversion module are composed of standard 5V CMOS devices, the logic enhancement module is used for enhancing logic signals output by a received main controller module in a staged mode, the level conversion module is used for carrying out logic level conversion between a low-voltage domain and a high-voltage domain, the driving module is connected with the output end of the logic enhancement module and converting the enhanced logic signals into driving levels suitable for an external power N-MOS tube, the power supply module is used for providing driving voltages higher than power supply voltage for the driving module, and the driving module is composed of high-voltage NLDMOS or NDEMOS devices. The scheme provided by the application can reduce the area and the manufacturing cost of the driving circuit chip, improve the switching speed and the working frequency of the driving circuit and reduce the power consumption of the circuit.

Inventors

LI BINBIN
HUANG ZHI
GENG JIANQIN

Assignees

广州博之源科技有限公司

Dates

Publication Date: 20260508
Application Date: 20251231

Claims (9)

1. The utility model provides a switching power supply high limit N-MOS drive circuit which characterized in that includes: the device comprises a main controller module, a logic enhancement module, a level conversion module, a driving module, a power supply module and an external power N-MOS tube; The logic enhancement module comprises two or more sub-modules which are respectively connected among the main controller module, the level conversion module and the driving module and used for enhancing the logic signals output by the received main controller module in a staged manner; the level conversion module is connected between the sub-modules of the logic enhancement module and is used for carrying out logic level conversion between a low-voltage domain and a high-voltage domain; The driving module is connected with the output end of the logic enhancement module and converts the enhanced logic signal into a driving level suitable for an external power N-MOS tube; The power supply module is connected with the logic enhancement module and the driving module and is used for providing driving voltage higher than power supply voltage for the driving module; The logic enhancement module and the level conversion module are composed of standard 5V CMOS devices, and the driving module is composed of high-voltage NLDMOS or NDEMOS devices.
2. The switching power supply high side N-MOS drive circuit of claim 1, wherein: The logic enhancement module comprises a first logic enhancement module, a second logic enhancement module, a third logic enhancement module, a fourth logic enhancement module and a fifth logic enhancement module; the level conversion module comprises a first level conversion module and a second level conversion module; the input end of the first logic enhancement module receives a logic signal output by the main controller module, and the output end of the first logic enhancement module is connected with the input end of the first level conversion module; The output end of the first level conversion module is connected with the input end of the second logic enhancement module, and the output end of the second logic enhancement module is respectively connected with the input ends of the third logic enhancement module and the fifth logic enhancement module; the output end of the third logic enhancement module is connected with the input end of the second level conversion module, and the output end of the second level conversion module is connected with the input end of the fourth logic enhancement module; the output end of the fourth logic enhancement module is connected with the driving module; And the output end of the fifth logic enhancement module is connected with the driving module.
3. The switching power supply high side N-MOS drive circuit of claim 2, wherein: The reference end of the first logic enhancement module is grounded, and the power supply voltage is the power supply voltage VCC output by the power supply module; the reference voltage of the second logic enhancement module is a first reference voltage SW, the power supply voltage is SW+Boot1, boot1 is a first bootstrap voltage, and the first bootstrap voltage Boot1 is output by the power supply module; the reference voltage of the third logic enhancement module is a first reference voltage SW, and the power supply voltage is SW+Boot1; The fourth logic enhancement module reference voltage is a second reference voltage VS, the power supply voltage is VS+Boot2, boot2 is a second bootstrap voltage, and the second bootstrap voltage Boot2 is output by the power supply module; the reference voltage of the fifth logic enhancement module is a first reference voltage SW, and the power supply voltage is SW+Boot1; The first level conversion module converts the logic level from GND to VCC voltage domain into a voltage domain from SW to SW+Boot1; the second level conversion module converts the SW to SW+Boot1 voltage domain logic level to VS to VS+Boot2 voltage domain.
4. The switching power supply high side N-MOS drive circuit of claim 2, wherein: the driving module comprises a high-side driving tube HS_NLDMOS and a low-side driving tube LS_NLDMOS; the grid electrode of the high-side driving tube HS_NLDMOS is connected with the output end of the fourth logic enhancement module, and the drain electrode of the high-side driving tube HS_NLDMOS is connected with the driving power supply output end of the power supply module; the grid electrode of the low-side driving tube LS_NLDMOS is connected with the output end of the fifth logic enhancement module, and the source electrode of the low-side driving tube LS_NLDMOS is connected with a first reference voltage SW; The drain electrode of the low-side driving tube LS_NLDMOS is connected with the source electrode of the high-side driving tube HS_NLDMOS and the drain electrode of the external power N-MOS tube; The source electrode of the high-side driving tube HS_NLDMOS or the drain electrode of the low-side driving tube LS_NLDMOS outputs an enhanced driving signal HS_DRV, and the HS_DRV signal is used for controlling the on or off of the external power N-MOS tube.
5. The switching power supply high side N-MOS drive circuit of claim 1, wherein the power supply module comprises: the driving power supply VCCX, a first diode D1, an LDO module, a first capacitor C1, a second capacitor C2, a second diode D2, a third capacitor C3, a third diode D3 and a fourth capacitor C4; The driving power supply VCCX is connected with the LDO module, and is output from a Vccx end of the LDO module after passing through a first diode D1 in the LDO module, wherein the Vccx end is connected with the driving module and a first capacitor C1, and the other end of the first capacitor C1 is connected with a first reference voltage SW; The driving power supply VCCX outputs a power supply voltage through a VCC end after being processed by an LDO module, and the VCC end of the LDO module is connected with a second capacitor C2, an anode of a second diode D2 and an anode of a third diode D3; the other end of the second capacitor C2 is grounded; The cathode of the second diode D2 is connected with one end of a third capacitor C3, the voltage of the cathode end of the second diode D2 is a first bootstrap voltage Boot1, and the other end of the third capacitor C3 is connected with a first reference voltage SW; the cathode of the third diode D3 is connected with a fourth capacitor C4, the voltage of the cathode end of the third diode D3 is the second bootstrap voltage Boot2, and the other end of the fourth capacitor C4 is connected with a second reference voltage VS.
6. The switching power supply high side N-MOS drive circuit of claim 5, wherein: The voltage value of the Vccx end is the voltage value of the driving power supply VCCX minus the voltage drop of the first diode D1, the Vccx voltage is the gate driving voltage of the external power N-MOS tube, and the Vccx voltage can be set to 12V, 20V or other voltage values according to the specification of the external power N-MOS tube; The voltage value of the power supply voltage output by the VCC end after the driving power supply VCCX is processed by the LDO module is 5V or 3.3V.
7. A driving method of a switching power supply high-side N-MOS driving circuit, which is applicable to the switching power supply high-side N-MOS driving circuit according to any one of claims 1 to 6, characterized by comprising: when the external power N-MOS tube is required to be turned on or turned off, the main controller module outputs a logic signal; the logic enhancement module is used for enhancing the logic input signal; The level conversion module converts the enhanced logic signal between a low-voltage domain and a high-voltage domain; providing a driving level higher than a power supply voltage for the driving module through the power supply module; the driving module outputs a driving signal to the grid electrode of the external power N-MOS, and the on-off of the grid electrode is controlled; the logic enhancement module and the level conversion module adopt standard 5V CMOS devices.
8. The driving method of the switching power supply high-side N-MOS driving circuit according to claim 7, wherein: When the external power N-MOS tube is required to be conducted, the main controller module generates a high-level logic signal, and the logic signal is enhanced by the first logic enhancing module; The enhanced high-level logic signals are sent to a first level conversion module, and the first level conversion module converts the high-level logic signals from GND to VCC voltage domains into SW to SW+Boot1 voltage domains; then through a second logic enhancement module, a third logic enhancement module, a fourth logic enhancement module and a second level conversion module, the second level conversion module converts high-level logic signals from SW to SW+Boot1 voltage domains into VS to VS+Boot2 voltage domains, the grid voltage of the high-side driving tube HS_NLDMOS is controlled to be Boot2, and the high-side driving tube HS_NLDMOS is conducted; meanwhile, the low level output by the fifth logic enhancement module enables the grid voltage of the low-side driving tube LS_NLDMOS to be 0V, and the low-side driving tube LS_NLDMOS is turned off; the voltage of a driving signal HS_DRV output by the high-side driving tube HS_NLDMOS is raised to SW+VCCX, and the gate source voltage of the external power N-MOS tube is controlled to be the driving voltage Vccx, so that the external power N-MOS tube is conducted.
9. The driving method of the switching power supply high-side N-MOS driving circuit according to claim 7, wherein: When the external power N-MOS tube needs to be turned off, the main controller module generates a logic signal with low level and is enhanced by the first logic enhancing module; The enhanced low-level logic signal is sent to a first level conversion module, and the first level conversion module converts the low level of GND to VCC voltage and the low level into SW to SW+Boot1 voltage domain; then through a second logic enhancement module, a third logic enhancement module, a fourth logic enhancement module and a second level conversion module, the second level conversion module converts low-level signals from SW to SW+Boot1 voltage domain into VS to VS+Boot2 voltage domain, and controls the grid voltage of the high-side driving tube HS_NLDMOS to be 0V so as to switch off the high-side driving tube HS_NLDMOS; Meanwhile, the high level output by the fifth logic enhancement module enables the grid voltage of the low-side driving tube LS_NLDMOS to be the Boot1 voltage, and the low-side driving tube LS_NLDMOS is conducted; The driving signal HS_DRV output by the low-side driving tube LS_NLDMOS is pulled down to SW, the grid voltage of the external power N-MOS tube is controlled to be 0V, and the external power N-MOS tube is turned off.

Description

High-side N-MOS driving circuit and driving method for switching power supply Technical Field The application relates to the technical field of switching power supplies, in particular to a high-side N-MOS driving circuit and a driving method of the switching power supply. Background In a DCDC switching power supply system, in order to boost output power, an external power MOS transistor is often used as a switching device. Particularly, in the high-side position of the half-bridge or full-bridge topology, an N-type power MOS transistor is usually selected for comprehensive consideration of on-resistance and cost. In order to ensure reliable conduction of the external power tube, the driving voltage of the external power tube is generally set to be about 12V, so that when the high-side external power tube MOS is conducted, a voltage of VIN plus 12V is needed to be turned on, and the external Vccx voltage is generally adopted as power supply of the driving part. Typically, vccx has a voltage of 12V, and thus devices inside the driver chip are required to satisfy a withstand voltage of 12V or higher. The high-voltage device with higher voltage-resistant grade is adopted to realize the driving logic, so that a large amount of high-voltage devices of the CMOS BCD process are used, the larger chip layout area is occupied, the cost of the whole circuit chip is increased, and meanwhile, the driving speed in the chip is reduced by adopting the high-voltage device driving chip, and the high-voltage device driving chip cannot be used under higher switching frequency. And an independent 12V Vccx power supply is introduced, when the logic level swing is carried out under a 12V high-voltage power supply domain, the switch node voltage is pulled up to 12V or pulled down to 0V, more charges are required to be consumed, and the static and dynamic power consumption of the driving circuit is increased. Therefore, a new high-side N-type MOS driving circuit and driving method are needed, which can use 5V standard CMOS devices to form a driving circuit on the premise of ensuring the generation of reliable high-voltage driving signals, so as to achieve the comprehensive goals of reducing the chip area, reducing the cost, improving the switching speed and reducing the overall power consumption. Disclosure of Invention In order to solve or partially solve the problems in the related art, the application provides a high-side N-MOS driving circuit and a driving method of a switching power supply, and aims to solve the technical problem that a high-voltage-resistant device is adopted for driving a high-side external power MOS tube. The first aspect of the present application provides a switching power supply high-side N-MOS driving circuit, comprising: the device comprises a main controller module, a logic enhancement module, a level conversion module, a driving module, a power supply module and an external power N-MOS tube; The logic enhancement module comprises two or more sub-modules which are respectively connected among the main controller module, the level conversion module and the driving module and are used for enhancing logic signals output by the received main controller module in a staged manner; The level conversion module is connected between the sub-modules of the logic enhancement module and is used for carrying out logic level conversion between the low-voltage domain and the high-voltage domain; The driving module is connected with the output end of the logic enhancement module and converts the enhanced logic signal into a driving level suitable for the external power N-MOS tube; The power supply module is connected with the logic enhancement module and the driving module and is used for providing driving voltage higher than power supply voltage for the driving module; the logic enhancement module and the level conversion module are composed of standard 5V CMOS devices, and the driving module is composed of high-voltage NLDMOS or NDEMOS devices. The logic enhancement module comprises a first logic enhancement module, a second logic enhancement module, a third logic enhancement module, a fourth logic enhancement module and a fifth logic enhancement module, wherein the level conversion module comprises a first level conversion module and a second level conversion module, the input end of the first logic enhancement module receives logic signals output by the main controller module, the output end of the first logic enhancement module is connected with the input end of the first level conversion module, the output end of the first level conversion module is connected with the input end of the second logic enhancement module, the output end of the second logic enhancement module is respectively connected with the input ends of the third logic enhancement module and the fifth logic enhancement module, the output end of the third logic enhancement module is connected with the input end of the second level conversion module,