LMZ31530, LMZ31520 / Power on sequence

Ryuji

Guru 20090 points

Hello,

(1)

Are there any start up and shutdown sequence in any voltage ( Vbias, Enable, Vcc, and so on) ?

I believe that there is no start up / shutdown sequence in LMZ315x0.

However , please kindly let me know for confirmation.

(2)

Are there the power down waveform by Vcc ?

I can find the start up waveform and INH turn on / off wave form.

However there is not power down wave form.

Best Regards,

Ryuji Asaka

over 11 years ago

0 J Arrigo over 11 years ago

TI__Mastermind 28020 points

(1) There is no required sequence, but I would recommend holding INH low until both VIN & PVIN is above their UVLO before releasing the INH pin.

(2) There is no waveform showing shutdown during VIN/PVIN decreasing. It is recommended to have INH/UVLO to control shutdown.

0 Ryuji over 11 years ago in reply to J Arrigo

Guru 20090 points

Hello Arrigo san

shutdown during VIN/PVIN is not recommended ?

please let me know this reason.

Ryiji Asaka

0 J Arrigo over 11 years ago in reply to Ryuji

TI__Mastermind 28020 points

A controlled shutdown is always recommended. Relying on a falling VIN/PVIN is possible, but I would recommend setting the UVLO above the minimum to allow the internal circuitry to still have voltage headroom.

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LMZ31530, LMZ31520 / Power on sequence