Hello,
We encountered a problem when doing surge test on VOUT of TPS259827ONRGER.
In out design, voltage of VOUT can be 5V, 12V, or 24V depending on the input voltage. Output current can be up to 8.7A. We have three components between VOUT and GND as listed below.
- 0.1uF/50V ceramic capacitor (close to the output pins of TPS259827ONRGER).
- TVS, SMAJ45A (next to the third component below)
- Thyristor, TISP4040H1BJR-S (close to output connector)
The surge test was done with 1kV, 10/700us wave. We found it passed during positive pulse (even without TVS) but failed during negative pulse (with TVS). TVS is used for ESD purpose but also supposed to absorb negative surge pulse. However, the test result shows it doesn't work. Due to the 8.7A output current, we couldn't find any current limit parts during surge to be placed in series in VOUT without causing voltage drop and thermal issues.
We noticed that in the application circuit of TPS25982 datasheet, a Schottky diode (B520C-13-F) is used to absorb negative spikes. Does this negative spike also include negative surge pulse? Could you give any suggestion to protect the eFuse VOUT from the surge wave we tested?
Thank you!
