48V Reference Switch module gone out during short protection test

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GaryLee
Level 1
Level 1
First reply posted First question asked Welcome!

Hello,

I bought 48V- battery protection switch with 2ED4820-EM for referring my application of 48V 50~100A.

https://www.infineon.com/dgdl/Infineon-Infineon-R_48V_BATT_SWITCH10-UG-2021-20-v01_00-EN-UserManual-...

 

The main role of the switch was short protection, I tried to test performance and function of modules in case of external (load) short.

The module was controlled by Serial CLI and I configured basic setting on the driver. 
Since a target system current is not that high, I set minimum values on the driver and tried to test short circuit protection at the load. 
I've tried started short test by using power supply first 48V, 8.4A current Limit before Li-Ion battery short circuit test.

There was no other circuitaries or eletric parts between the switch and power supply. and Load was open.

As soon as i short output load LD+ to LD-, I saw a little spark and the switch turned off properly.
But as soon as i tried to turn FET on again,  I realized that gate driver doesn't respone to the CLI command (eg. read registers)
(need further investigation but not really able to debug because of huge heat sink)

I thought it would be ok since there were current limit on the power supplier, and even I expected even short current would not that high so the gate is totally capable of handlihg short current. but now I have the module out of the function...

Referring the block diagram of Gate driver, I see the logic is operated by separated 5V from MCU board. so can somebody explain what circumstance could make gate driver logic controler out of function? (or can it be faulty module since i bought one from digikey....)

 

 

 

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1 Solution
Xiangrui
Moderator
Moderator
Moderator
500 replies posted 250 solutions authored 50 likes received

Hi GrayLee,

Thanks for choosing our product. 

Firstly, I'd like to know if you tested on your module or our kit. If you tested on your application. Please upload the schematic for checking the hardware connection. 

Furthermore, there may be a reason that you cannot turn on the MOSFET again:

To bring the device from safe state back to normal mode, the pin SAFESTATEN has to be set to high and the
failure flag SAFESTATE must be cleared via SAFESTATE_CL or FAIL_RST_0 together with FAIL_RST_1.
If the microcontroller sets the ENABLE pin to low, the device enters the sleep mode.

BR,

Xiangrui

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3 Replies
Xiangrui
Moderator
Moderator
Moderator
500 replies posted 250 solutions authored 50 likes received

Hi GrayLee,

Thanks for choosing our product. 

Firstly, I'd like to know if you tested on your module or our kit. If you tested on your application. Please upload the schematic for checking the hardware connection. 

Furthermore, there may be a reason that you cannot turn on the MOSFET again:

To bring the device from safe state back to normal mode, the pin SAFESTATEN has to be set to high and the
failure flag SAFESTATE must be cleared via SAFESTATE_CL or FAIL_RST_0 together with FAIL_RST_1.
If the microcontroller sets the ENABLE pin to low, the device enters the sleep mode.

BR,

Xiangrui

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GaryLee
Level 1
Level 1
First reply posted First question asked Welcome!

Thank you for your quick reponse Xiangrui,

The test was only with 4 components,
48V Power Supply
48V Switch Kit : Switch Module + Control Module, bought from digikey
So I didn't connect any application circuit between / other than your kit

I attached current status of the switch module kit
(control module kit seems ok since I could see LEDs and can input CLI command and there is reponse)
As you can see the gate driver doesn't reponse to the read all command. (It was ok before short test)

I'm going to replace the gate driver on the kit with new gate driver to see if the kit come back OK
I'm just wondering performance of the kits. since if it's get permanent damaged It will get out even I repair the kit....
(and wondering If i missing any application requirement against short condition!

GaryLee_0-1678955419104.png

 

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Xiangrui
Moderator
Moderator
Moderator
500 replies posted 250 solutions authored 50 likes received

Hi Gary Lee,

It's hard to say which part is damaged by over current.

Actually this product is not designed for this strict situation. There should be a pre charge circuit for over current when load capacitor is empty. This means a shoot through from 48V to 0V should be avoided during operation, especially for the low ohmic circuit.

Now I suggest to test firstly the voltage on VDD and VCP to check if the logic and power supply work well. 

If so, then compare GA1&SA1 with GA2&SA2 to check internal driver. (pre charge circuit can be a reference, because i guess it wasn't affected by short circuit test.) 

At last you can replace the 2ED4820-EM with a new one. If it still doesn't work, it means there is somewhere else on the board damaged.

BR,

Xiangrui

 

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