TPS24701: TPS24701 Test issue

Jimmy Lai

Part Number: TPS24701
Other Parts Discussed in Thread: CSD17581Q3A, CSD16401Q5,

Dear Team,

After a lot of experiments, we found that within the MOS tube specification, no matter what the OCP value is, once the overcurrent protection is triggered, the MOS tube will be protected for a short time, and then it will be broken down, and the gap between G, D or G, GND increases. RC has nothing to do with it.

Debugging process: Change R sense from 0.001Ω to 0.006Ω, reduce the OCP point from 25A to 4.17A. Power on the power supply, load CC pull, slowly increase to 3.9A, trigger OCP protection, and the current is the largest at this time value is 4.2A,
4.2A is far smaller than the specification of the MOS tube [MOSFET N-CH CSD17581Q3A 30V 60A SON3X3 TI], but the MOS tube is broken down after about 12s. The waveform is as follows:

This problem is more urgent, and many projects have similar problems. Please guide us to find out why, thank you very much!

Many Thanks,

Jimmy

Many Thanks,

Jimmy

over 2 years ago

0 Avishek Pal over 2 years ago

TI__Mastermind 33035 points

Hi Jimmy,

Thanks for reaching out. I will get back to you tomorrow.

0 Avishek Pal over 2 years ago in reply to Avishek Pal

TI__Mastermind 33035 points

Hi Jimmy,

CSD17581Q3A doesn't have adequate SOA which is required here for the design, even if the sense resistor is changed to 6 mΩ to reduce the current limit. Please use CSD16401Q5 and make the C8PMB1 as 12 nF.

0 Jimmy Lai over 2 years ago in reply to Avishek Pal

TI__Expert 6845 points

Hi Pal,

We appreciated your great support!

TPS24701 OCP test damage MOS problem
----- The opinion you gave is to replace 100AMOS, the two packages are different, it is difficult to change the material because of too much influence.
Because our product is already in mass production,

1. CSD17581Q3A From the datesheet, the SQA curve is limited to about 15A when it is DC. What is the specific reason why you are not satisfied?
2. When the sense resistance is changed by 6 mΩ, the OCP is 4.25A at this time, which cannot exceed the SOA specification of MOS, which is unreasonable.

Many Thanks,

Jimmy

0 Avishek Pal over 2 years ago in reply to Jimmy Lai

TI__Mastermind 33035 points

Hi Jimmy,

Below is the SOA curve of CSD17581Q3A and the "RED" line corresponds to DC. May I know how you are getting 15 A data?

In your schematic, C_TIMER = 68 nF, which corresponds to a timer duration of around 10 ms. Maximum allowable current is only 2A.

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TPS24701: TPS24701 Test issue