BQ79600-Q1: BQ79600 EVM not answering requests

Olaf Cichewicz

Part Number: BQ79600-Q1

Tool/software:

We have the same problem as described in an already existing post. A BQ79600 EVM is not answering to a sequence that should trigger an answer.
The sequence is verified on another setup with a target HW using the BQ79600. Although the BQ reacts to a COMM CLEAR ping and a request with its SPI_RDY signal it never provides the requested data. The snapshots show what's happening on the SPI seen by a logic analyzer (try with 5 MHz SPI clock) and a scope.(try with 2 MHz SPI clock).

Sequence steps:

Logic analyzer:

Scope (to check signal quality):

Silicon version:

3 months ago

0 Benjamin Luty 3 months ago

TI__Expert 7060 points

Olaf,

You cannot read from the BQ79600 before completing the step of auto-addressing, even if it is a single device. You can find more information in section 7.3.2.3.1 of the datasheet.

Regards,

0 Olaf Cichewicz 3 months ago

Prodigy 10 points

Hi Bo,

unfortunately this does not solve my problem.
When I'm sending the whole auto addressing sequence as described in the manual it behaves the same. SPI_RDY goes LOW after a request and never rises.

First I'm sending two WAKE pings, chip wakes up successfully:

This is the suggested sequence I'm sending pretty slow:

On the SPI it looks like:

Here is a zoom of the first stack read:

And the details:

It shows the same. SPI_RDY is going low and remains there.

I have the feeling certain chips on the EVMs might have a problem because the ones with other markings on target prototypes are behaving as expected.

Two not answering chips: