BQ40Z80: OCD detection delay time

LOIC REBOUSSIN

Expert 1620 points

Part Number: BQ40Z80

Hi Team,

Can you explain how current protection timing sample operates and how I can program the delay time step as below?

Loïc

over 1 year ago

0 Wyatt Keller over 1 year ago

TI__Guru** 105770 points

Hello Loic,

We have some guidance on this in the FAQ pages: https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1127899/faq-bq40z80-faqs

Specifically the FAQ on the differences between FW and HW protections: https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1111094/faq-what-are-the-differences-between-the-hardware-and-firmware-protections

Sincerely,

Wyatt Keller

0 LOIC REBOUSSIN over 1 year ago in reply to Wyatt Keller

Expert 1620 points

Hello Wyatt,

I follow the FAQ and the OCD question is'nt answered. I can only set the OCD for each second, not for delay time in ms. My question is about the behavior of the current measurement for pulsed current shape and the OCD detection.

Please can you explain ?

Regards LOIC

0 Wyatt Keller over 1 year ago in reply to LOIC REBOUSSIN

TI__Guru** 105770 points

Hello Loic,

I'm not sure I understand your question, the bq40z80 has hardware and firmware protections, the hardware protections the current must be over the threshold for the entire delay time, if it dips below during a pulse it may reset the protection time.

Firmware protections are based on 250ms conversion time samples from our CC ADC, decisions are made on a second by second basis and the current measured by the ADC must be above the OCD threshold for the required delay time or it will not trip.

Sincerely,

Wyatt Keller

Power management

Power management forum

BQ40Z80: OCD detection delay time