TPS2384: POE asserted with no external ethernet device connected

paul corcoran

Prodigy 90 points

Part Number: TPS2384

Using tps2384 in our poe switch design.

Occasional failure. POE asserted with no external ethernet device connected even after a power cycle.

Rework and replace tps2384 fixes problem.

Question what internal registers should i examine to determine what is going on.

Are there any register bits that could override the detection mechanism and leave POE asserted all the time.

thanks

Paul

over 6 years ago

0 Darwin Fernandez over 6 years ago

TI__Mastermind 41790 points

Hi Paul,

Are you operating in auto mode, semi auto mode, or manual mode? In auto mode, the port shouldn't turn on unless there is a valid detection. When in semi or manual mode, you must actively do a power on command to turn on the port.

Nonetheless, I don't expect the IC to damage during a port turn ON (whether it was from a command or not). Damage should come from a the IC exceeding its abs max ratings described in the datasheet. Can you check what node on your board might be damaging the part (for example, an overvoltage on one of the pins)?

0 paul corcoran over 6 years ago in reply to Darwin Fernandez

Prodigy 90 points

The TPS2384 is operating in Auto mode.

0 Darwin Fernandez over 6 years ago in reply to paul corcoran

TI__Mastermind 41790 points

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TPS2384: POE asserted with no external ethernet device connected