TPSM63603: EN/SYNC Float

Hirotsugu Kobayashi

Part Number: TPSM63603
Other Parts Discussed in Thread: LMR33630

Hi team,

What happens if the EN/SYNC terminal is left floating?
There is a period when the control signal is floating, so I would like to know the behavior.

Best Regards,

9 months ago

0 Elena Gao 9 months ago

TI__Genius 13735 points

hi, Hirotsugu,

EN need to High = on, Low = off. A floating pin may couple the noisy, lead device not on/off right. Suggest a resistor connect on EN to Vin and EN to GND to avoid any abnormal.

Elena

0 Hirotsugu Kobayashi 9 months ago in reply to Elena Gao

Mastermind 8785 points

Hi Elena,

Attached is the current system.
It is controlled by a reset IC, but since the reset IC's power supply is delayed, there is a period when EN/SYNC is floating.

When EN/SYNC is floating, does it turn on or off?

Will it be turned off if I pull down the EN/SYNC terminal?

Is the EN/SYNC pin pulled up internally?

Best Regards,

0 Elena Gao 9 months ago in reply to Hirotsugu Kobayashi

TI__Genius 13735 points

hi, Hirotsugu,

Looking from the block, 5V on, EN enable, 5V is not power on, the reset IC output is LOW, and EN state is LOW, so LMR33630 will disable,

Answer your question:

When EN/SYNC is floating, does it turn on or off?----the EN is off

Will it be turned off if I pull down the EN/SYNC terminal?----yes

Is the EN/SYNC pin pulled up internally?----no

Elena

0 Hirotsugu Kobayashi 9 months ago in reply to Elena Gao

Mastermind 8785 points

Hi Elena,

The reset IC output is floating instead of low until the reset IC is powered.
Therefore, I want to make it clear whether it is ON or OFF when floating.

If it cannot be specified, add a pull-down resistor.

Best Regards,

+1 Elena Gao 9 months ago in reply to Hirotsugu Kobayashi

TI__Genius 13735 points

When EN floating the statue is uncertain, suggest connect to Vin or GND to avoid abnormal .

Elena

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TPSM63603: EN/SYNC Float