EP-4737918-A1 - A POWER DEVICE SYSTEM

EP4737918A1EP 4737918 A1EP4737918 A1EP 4737918A1EP-4737918-A1

Abstract

A power device system (100) comprising: a power device (101) and a controller (102), the power device (101) comprising: a power switch (103); and a control terminal driver (104), and wherein the power device (101) is configured to operate in both a ramp-up and ramp-down diagnostic mode in which the control terminal driver (104) is respectively configured to: apply a test current at the first node of the conduction channel (105) of the power switch (103); apply a first driver voltage that is less than or greater than the threshold voltage at control terminal (106) of the power switch (103); increase or decrease, respectively, the first driver voltage until a voltage drop or voltage increase, respectively is detected; and measure the first driver voltage at which the voltage drop is detected as a ramp-up threshold voltage or ramp-down threshold voltage, respectively, wherein the controller (102) is configured to determine a state of health of the power switch (101) based on the ramp-up threshold voltage and the ramp-down threshold voltage.

Inventors

Ryabchenkov,, Sergey Sergeevich
Kandah,, Ibrahim Shihadeh
BOURLOT,, Xavier Antoine Theophile

Assignees

NXP USA, Inc.

Dates

Publication Date: 20260506
Application Date: 20241029

Claims (13)

A power device system comprising: a power device and a controller, the power device comprising: a power switch comprising a conduction channel and a control terminal wherein current is configured to flow from a first node of the conduction channel to a second node of the conduction channel upon a voltage at the control terminal reaching a threshold voltage; and a control terminal driver configured to control a voltage applied to the control terminal of the power switch, and wherein the power device is configured to operate in a power switch diagnostic mode comprising both a ramp-up diagnostic mode and a ramp-down diagnostic mode, wherein in the ramp-up diagnostic mode, the control terminal driver is configured to: apply a test current at the first node of the conduction channel; apply a first driver voltage that is less than the threshold voltage at the control terminal; increase the first driver voltage until a voltage drop across the conduction channel of the power switch is detected; and measure the first driver voltage at which the voltage drop is detected as a ramp-up threshold voltage; and in the ramp-down diagnostic mode, the control terminal driver is configured to: apply the test current to the first node of the conduction channel; apply a second driver voltage that is greater than the threshold voltage at the control terminal; decrease the second driver voltage until a voltage increase across the conduction channel of the power switch is detected; and measure the second driver voltage at which the voltage increase is detected as a ramp-down threshold voltage; and wherein the controller is configured to determine a state of health of the power switch based on the ramp-up threshold voltage and the ramp-down threshold voltage.
The power device system of claim 1 wherein the controller is configured to determine the state of health of the power switch by comparing the ramp-up threshold voltage and the ramp-down threshold voltage to one or more historical threshold voltages.
The power device system of claim 2 wherein the historical threshold value is stored in a memory of the controller.
The power device system of any preceding claim wherein, in the ramp-up diagnostic mode, the control terminal driver is configured to apply a first preconditioning voltage at the control terminal for a first preconditioning time wherein the first preconditioning voltage and the first preconditioning time are the same each time the ramp-up diagnostic mode is utilised.
The power device system of any preceding claim wherein, in the ramp-down diagnostic mode, the control terminal driver is configured to apply a second preconditioning voltage at the control terminal for a second preconditioning time wherein the second preconditioning voltage and the second preconditioning time are the same each time the ramp-down diagnostic mode is utilised.
The power device system of claim 4 and claim 5 wherein the first preconditioning time is the same as the second preconditioning time.
The power device system of any preceding claim wherein the power device is configured to operate in the power switch diagnostic mode a plurality of times in succession such that a plurality of ramp-up threshold voltages and ramp-down threshold voltages are recorded wherein, each time the power device operates in the power switch diagnostic mode, a different test current is used and wherein the controller is configured to determine a transconductance of the power switch based on the plurality of ramp-up threshold voltages and the ramp-down threshold voltages and wherein the state of health of the power switch is based on the transconductance of the power switch.
The power device system of any preceding claim further comprising a comparator configured to detect the voltage drop or the voltage increase across the conduction channel of the power switch.
The power device system of any preceding claim further comprising an analog-to-digital converter configured to measure the voltage applied to the control terminal of the power switch when a voltage drop or voltage increase is detected across the conduction channel of the power switch.
The power device system of any preceding claim wherein the power device comprises a temperature sensor configured to determine a temperature at the power switch and wherein the controller is configured to determine the state of health of the power switch further based on the determined temperature.
The power device system of any preceding claim wherein the control terminal driver is an intelligent gate driver.
A power apparatus comprising the power device system of any preceding claim.
A method of determining a state of health of a power switch comprising a conduction channel and a control terminal, wherein current is configured to flow from a first node of the conduction channel to a second node of the conduction channel upon a voltage at the control terminal reaching a threshold voltage, the method comprising: applying a test current to the first node of the conduction channel; applying, by way of a control terminal driver, a first driver voltage less than the threshold voltage at the control terminal; increasing, by way of the control terminal driver, the first driver voltage until a voltage drop across the conduction channel of the power switch is detected; measuring the voltage at which the voltage drop was detected as a ramp-up threshold voltage; applying the test current to the first node of the conduction channel; applying, by way of the control terminal driver, a second driver voltage greater than the threshold voltage at the control terminal; decreasing, by way of the control terminal driver, the second driver voltage until a voltage increase across the conduction channel of the power switch is detected; measuring the voltage at which the voltage increase the voltage increase is detected as a ramp-down threshold voltage; and determining a state of health of the power switch based on the ramp-up threshold voltage and the ramp-down threshold voltage.

Description

Field The present disclosure relates to a power device system, power apparatus and a method of determining the state of health of a power switch. Summary According to a first aspect of the present disclosure, there is provided a power device system comprising: a power device and a controller, the power device comprising: a power switch comprising a conduction channel and a control terminal wherein current is configured to flow from a first node of the conduction channel to a second node of the conduction channel upon a voltage at the control terminal reaching a threshold voltage; and a control terminal driver configured to control a voltage applied to the control terminal of the power switch, and wherein the power device is configured to operate in a power switch diagnostic mode comprising both a ramp-up diagnostic mode and a ramp-down diagnostic mode, wherein in the ramp-up diagnostic mode, the control terminal driver is configured to: apply a test current at the first node of the conduction channel; apply a first driver voltage that is less than the threshold voltage at the control terminal; increase the first driver voltage until a voltage drop across the conduction channel of the power switch is detected; and measure the first driver voltage at which the voltage drop is detected as a ramp-up threshold voltage; and in the ramp-down diagnostic mode, the control terminal driver is configured to: apply the test current to the first node of the conduction channel; apply a second driver voltage that is greater than the threshold voltage at the control terminal; decrease the second driver voltage until a voltage increase across the conduction channel of the power switch is detected; and measure the second driver voltage at which the voltage increase is detected as a ramp-down threshold voltage; and wherein the controller is configured to determine a state of health of the power switch based on the ramp-up threshold voltage and the ramp-down threshold voltage. In one or more embodiments, the controller may be configured to determine the state of health of the power switch by comparing the ramp-up threshold voltage and the ramp-down threshold voltage to one or more historical threshold voltages. In one or more embodiments, the historical threshold value may be stored in a memory of the controller. In one or more embodiments, in the ramp-up diagnostic mode, the control terminal driver may be configured to apply a first preconditioning voltage at the control terminal for a first preconditioning time wherein the first preconditioning voltage and the first preconditioning time are the same each time the ramp-up diagnostic mode is utilised. In one or more embodiments, in the ramp-down diagnostic mode, the control terminal driver may be configured to apply a second preconditioning voltage at the control terminal for a second preconditioning time wherein the second preconditioning voltage and the second preconditioning time are the same each time the ramp-down diagnostic mode is utilised. In one or more embodiments, the first preconditioning time may be the same as the second preconditioning time. In one or more embodiments, the power device may be configured to operate in the power switch diagnostic mode a plurality of times in succession such that a plurality of ramp-up threshold voltages and ramp-down threshold voltages are recorded wherein, each time the power device operates in the power switch diagnostic mode, a different test current is used and wherein the controller is configured to determine a transconductance of the power switch based on the plurality of ramp-up threshold voltages and the ramp-down threshold voltages and wherein the state of health of the power switch is based on the transconductance of the power switch. In one or more embodiments, the power device system may further comprise a comparator configured to detect the voltage drop or the voltage increase across the conduction channel of the power switch. In one or more embodiments, the power device system may further comprise an analog-to-digital converter configured to measure the voltage applied to the control terminal of the power switch when a voltage drop or voltage increase is detected across the conduction channel of the power switch. In one or more embodiments, the power device may comprise a temperature sensor configured to determine a temperature at the power switch and wherein the controller is configured to determine the state of health of the power switch further based on the determined temperature. In one or more embodiments, the control terminal driver may be an intelligent gate driver. According to a second aspect of the present disclosure, there is provided a power apparatus comprising the power device system of any preceding claim. According to a third aspect of the present disclosure, there is provided a method of determining a state of health of a power switch comprising a conduction channel and a control terminal, wherein cur