TPS3430-Q1: WDO pin cannot Change of state

Hi Lawrence,

In the first waveform screenshot the WDO(LHM_WDO) is in HIGH status, in the second waveform the WDO(LHM_WDO) is in LOW status , and in the third waveform WDO(LHM_WDO) is in LOW status. I do not see your issue of WDO pin always stuck HIGH. Could you please clarify your issue?

Thanks,
Joshua

Hi, Joshua

sorry to clarify, we talk about is LHM_WDO_OUT status.

If Power on default waveform:

LHM_WDI have a pulse

LHM_WDO is High status

LHM_WDO_OUT is Low status

command output off waveform:

LHM_WDO is Low status

LHM_WDO_OUT is High status

command output on waveform:

LHM_WDI have a pulse

LHM_WDO is Low stasus

LHM_WDO_OUT is High status

our client concern is Chart1 and Chart 3, They have a pulse waveform(LHM_WDI), but chart 3 (LHM_WDO) should change to High status and (LHM_WDO_OUT) should change to Low status. why is different with chart 1?

if any suggestion, Please advise me.

Thanks,

Best regards,

Lawrence

Hi Lawrence,

The TPS3430-Q1 device is a window watchdog which requires the watchdog input(WDI) pulse to be provided within the window boundary. For your circuit SET0 and SET1 are both pulled high therefore your window is typically between 800ms and 1600ms. Accounting for watchdog error your window in worst case would be 920ms to 1360ms. Is the LHM_WDI pulse provided in chart 3 within this valid window? I also see that your LHM_WDI pulse occurs while WDO is low, the input at WDI is ignored when WDO is low. Could you have the customer increase the time scale and take a scope shot that captures multiple reset cycles, similar to Figure 8-5 in the datasheet.

Thanks,
Joshua

Hi Joshua

Attached are my test images.

When WDI starts sending pulses, WDO does not go high.

Hi Joshua

I have removed the oscilloscope screenshot of UIC1010.

1. The trigger mode is now functioning correctly.
2. However, WDO has become a PWM output. How can this be resolved?

Thanke

Hi Amy,

When in fault condition, expected device behavior is WDO PWM.

Thanks,
Joshua