BQ76972: The RST_SHUT pin was used to reset, but the previously set parameters did not fully restore the default values

lin quan

Part Number: BQ76972

hi：

use chip： BQ7697204

Configure the chip to enable REG1 to output 5V, REG2 to output 1.8V, and then reset via the RST_SHUT pin: Pull the RST_SHUT pin up 300ms and pull it down again, and find that the REG1 output can only recover from 5V to the default 3.3V, but REG2 still outputs 1.8V.

Shouldn't REG2 revert to the default output 0V after reset?

Is this a normal phenomenon? Is it because the reset does not change the output parameters of RGE2?

3 个月前

0 Lydia 2 个月前

TI__Genius 11415 points

Hi,

Pulling up RST_SHUT for <1s only performs a partial reset, which does not reset the data memory.

A full reset would require asserting RST_SHUT for <1s.

Regards,

0 lin quan 2 个月前回复 Lydia

Prodigy 90 points

What does it mean to assert that < 1 second? I need to control the RST_SHUT pin for a full reset. What should I do?

The RST_SHUT pin is pulled up for less than 1 second, but doing so is only a partial reset. Pull down the RST_SHUT pin and the chip is working properly

0 Lydia 2 个月前回复 lin quan

TI__Genius 11415 points

Hi，We will investigate and get back to you later.

0 Lydia 2 个月前回复 lin quan

TI__Genius 11415 points

Hi ,

For a full reset the RST_SHUT pin needs to be asserted for more than 1 second. This will put the part into shutdown mode. The device can then be woken up to complete the full reset.

Asserting the RST_SHUT pin for less than 1 second will only do a partial reset, which clears some internal logic, but does not reset the RAM.

Regards,

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BQ76972: The RST_SHUT pin was used to reset, but the previously set parameters did not fully restore the default values