CN-121984454-A - Grid protection system of power tube

CN121984454ACN 121984454 ACN121984454 ACN 121984454ACN-121984454-A

Abstract

The invention discloses a power tube grid protection system which comprises at least one power tube, a first clamping module and a dynamic delay module, wherein the first clamping module is connected with a power tube and used for limiting the voltage between a grid electrode and a source electrode of the power tube, and the dynamic delay module is respectively connected with the first clamping module and the power tube and used for carrying out delay control on the grid electrode voltage of the power tube so as to enable the grid electrode voltage to be delayed for a set time and then follow the voltage change of a drain electrode or the source electrode. The power tube multiplexing power tube can quickly release energy, so that voltage peaks are greatly restrained, and meanwhile, the clamping circuit which can be flexibly designed by matching with clamping voltage is used for protecting an internal module from gate oxide breakdown or junction breakdown.

Inventors

YANG QUAN
MAO LIQING
LIU ZHONGWEI
LIU JUANJUAN
WU TONG
LIN JINGJING
HE BIN
WANG NING
LIANG MENGXUE

Assignees

南通宁芯微电子有限公司
南京市智凌芯科技股份有限公司
无锡睿能芯电子科技有限公司
南宁智宁芯半导体有限公司

Dates

Publication Date: 20260505
Application Date: 20251225

Claims (10)

1. A power tube gate protection system comprising at least one power tube, further comprising: the first clamping module is connected with a power tube and used for limiting the voltage between the grid electrode and the source electrode of the power tube; And the dynamic delay module is respectively connected with the first clamping module and the power tube and is used for carrying out delay control on the grid voltage of the power tube so as to delay the grid voltage of the power tube for a set time and then to change along with the voltage of the drain electrode or the source electrode.
2. The power tube gate protection system of claim 1, wherein the dynamic delay module comprises: the delay power tube is respectively connected with the first clamping module and the power tube and is used for starting energy release of the power tube; The delay unit is respectively connected with the second clamping module and the delay power tube and is used for delaying the charging of the grid electrode of the power tube; And the second clamping module is respectively connected with the delay unit and the delay power tube and used for limiting the voltage between the grid electrode and the source electrode of the delay power tube.
3. The power tube gate protection system of claim 2, wherein the dynamic delay module further comprises: and the control module is respectively connected with the second clamping module and the delay power tube and is used for controlling the on/off of the delay power tube.
4. The power transistor gate protection system of claim 2, wherein the first clamp module and/or the second clamp module is comprised of at least one clamp unit comprising at least one of a diode, a metal oxide semiconductor field effect transistor, and a triode.
5. The power tube gate protection system of claim 4, wherein the first clamp module comprises a first diode and a second diode, a cathode of the first diode is connected to a gate of the power tube, an anode of the first diode is connected to an anode of the second diode, and a cathode of the second diode is connected to a source of the power tube.
6. The power tube gate protection system of claim 5, wherein the first clamp module further comprises a third diode, an anode of the third diode being connected to a cathode of the second diode, a cathode of the third diode being connected to a source of the power tube.
7. The power tube gate protection system of claim 5, wherein the first clamp module further comprises a fourth diode, an anode of the fourth diode being connected to a cathode of the first diode, a cathode of the third diode being connected to a source of the power tube.
8. The power transistor gate protection system of claim 4, wherein the first clamp module comprises a fifth diode and a metal oxide semiconductor field effect transistor, a cathode of the fifth diode is connected to a gate of the power transistor, an anode of the fifth diode is connected to a drain of the metal oxide semiconductor field effect transistor, and a power supply voltage is connected to the gate, the source, the body terminal, and the source of the power transistor, respectively.
9. The power tube gate protection system of claim 2, wherein the delay element is a current limiting circuit.
10. The power tube gate protection system of claim 9, wherein the current limiting circuit comprises a resistor, or a combination of a resistor and a capacitor.

Description

Grid protection system of power tube Technical Field The invention belongs to the technical field of power supply control, and relates to a power tube grid protection system. Background When a switch is switched or a load of a large current input/output (I/O) pin suddenly drops, a rapid change (di/dt) of current can induce a voltage spike with high frequency and high amplitude due to parasitic inductance. For high voltage linear charging chips, such spikes are very likely to occur at the battery terminal (BAT) pins, which may cause breakdown of the gate oxide or junction of the internal power transistor or related circuitry, resulting in permanent damage to the chip. To suppress such voltage spikes, prior art energy bleed schemes based on parasitic structures of power transistors are often employed. The scheme utilizes BAT pin voltage spike to trigger reverse breakdown (trigger voltage about 9.5V) of a parasitic diode between a power tube body region (Bulk) and a Source (Source), thereby forming a discharging path and limiting the spike voltage to about 9.5V. However, the effectiveness of this method is highly dependent on process stability. In practical manufacturing, if the thickness of the gate oxide layer is thinner or the doping concentration deviates, the gate oxide breakdown voltage (e.g. 10.5V) may be reversely lower than the PN junction breakdown voltage (e.g. 9.5V), which may lead to device failure. In addition, if the layout design fails to ensure uniform body region potential, breakdown unevenness and insufficient discharge can be caused, and even latch-up (latch-up) is induced in the energy discharge process, so that additional risks are brought. Another idea is to drain energy by means of electrostatic discharge (ESD) protection metal oxide semiconductor field effect transistors (MOS). The grid voltage of the protection tube is lifted through capacitive coupling, so that the protection tube is conducted in advance and enters a low breakdown voltage state, and the voltage spike is responded quickly. However, the scheme faces the difficulty of voltage matching in practical application, namely the typical value of breakdown voltage of a single 5V ESD protection tube is about 9.7V, and an actual peak of up to 18V cannot be born, and if two stages of protection tubes are used in series, the withstand voltage can be improved to about 19V, but the typical peak within the range of 12V-18V is difficult to react, so that protection failure is caused. In general, it is difficult to achieve reliable and safe energy release over a wide voltage range with existing protection schemes, and further optimization design is needed to cope with complex and variable working conditions and process fluctuations in practical applications. Disclosure of Invention The invention aims to overcome the defects in the prior art and provides a power tube grid protection system which can quickly release energy through multiplexing a power tube so as to greatly inhibit voltage spikes, and meanwhile, the power tube grid protection system is matched with a clamping circuit which can be flexibly designed by using clamping voltage to protect an internal module from grid oxide breakdown or junction breakdown. In order to achieve the above purpose, the invention is realized by adopting the following technical scheme: a power tube gate protection system comprising at least one power tube, further comprising: the first clamping module is connected with a power tube and used for limiting the voltage between the grid electrode and the source electrode of the power tube; And the dynamic delay module is respectively connected with the first clamping module and the power tube and is used for carrying out delay control on the grid voltage of the power tube so as to delay the grid voltage of the power tube for a set time and then to change along with the voltage of the drain electrode or the source electrode. Optionally, the dynamic delay module includes: the delay power tube is respectively connected with the first clamping module and the power tube and is used for starting energy release of the power tube; The delay unit is respectively connected with the second clamping module and the delay power tube and is used for delaying the charging of the grid electrode of the power tube; And the second clamping module is respectively connected with the delay unit and the delay power tube and used for limiting the voltage between the grid electrode and the source electrode of the delay power tube. Optionally, the dynamic delay module further includes: and the control module is respectively connected with the second clamping module and the delay power tube and is used for controlling the on/off of the delay power tube. Optionally, the first clamping module and/or the second clamping module is/are composed of at least one clamping unit, and the clamping unit comprises at least one of a diode, a metal oxide semiconductor field effect transistor and a t