• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 328 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS24720 EN noise susceptibility

Sturn
Prodigy 10 points
Other Parts Discussed in Thread: TPS24720

Hi,

We have a design that uses the TPS24720 hot-swap controller. Our schematic is nearly identical to the evaluation board schematic. Our resistor chain for the EN and OV pins is 12V -> 90.9k -> 4.42k -> 10k -> gnd. We then have a 1k resistor from the EN pin that goes to a switch that disables the controller by connecting EN to ground through the 1k.

We find that by simply touching the either the EN node or the switch side of the 1k, causes the TPS24720 to reset (cycles power). Adding a 10nF capacitor between the EN pin and GND fixes this issue. Seems like a high-impedance node problem, but the impedance is not that high.

With our 12V input and resistor chain, the EN pins sits nominally at 1.6V.

Have you seen similar susceptibility to noise?

Wondering if the eval board doesn't show this as the 1nF "debounce" cap is also filtering?

Thanks!