TPS929240-Q1: Fail-safe mode

Ivy Jin

Part Number: TPS929240-Q1

Tool/software:

Hi team,

My customer uses TPS929240-Q1 in their project and now they met below issue, could you please help review and give some comments?

Description of the issue: When communication is lost, the TPS929240-Q1 enters Fail Safe mode, but the LEDs are not lit as configured. The LEDs that were originally lit were turned off after entering FS mode.

May I know what is the potential cause of the LEDs not turning on at this time? Thank you.

The following is an example of channel D2 and below registers have been checked by customer.

FSOUTD2=0

ENOUTD2=1

FLA_EXTFS0=1, FLAG_FS=1

IOUTD2=3Fh

PWMMD2=FFh

The following is an example of channel D2:

Regards,

Ivy

5 months ago

0 Ivy Jin 5 months ago

TI__Expert 4935 points

Hi team,

May I ask if you have any update? Thanks!

Regards,

Ivy

+1 Xiaoguang 5 months ago in reply to Ivy Jin

TI__Genius 17660 points

Hi, Ivy,

Can customer read all registers data before run into FS mode and after FS mode? Usually, FLAG registers can tell you what happens.

If any fault happens and/or ERR pin been pull down after FS mode? If there is error, LEDs might turn off.

If FS0/1 pull to high as expected design setting?

0 Ivy Jin 5 months ago in reply to Xiaoguang

TI__Expert 4935 points

Hi Xiaoguang,

Please see the attached registers data before running into FS mode and after FS mode. The parts of the register with different values have been highlighted with the yellow box, and there is no fault happened.

When entering FS mode, the LEDs can be lit normally if the customer performs an unlock and initialization operation.

Xiaoguang said:
If FS0/1 pull to high as expected design setting?

Yes, the FLA_EXTFS0=1.

进入FS模式后无法亮灯.xlsx

Schematic:

Regards,

Ivy

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TPS929240-Q1: Fail-safe mode