TCAN1145-Q1: Episodic phenomenon, when sent WUP message to wake up the sleep mode TCAN1145-Q1, there is no level change on RX pin.

Steve Sun

Intellectual 1990 points

Part Number: TCAN1145-Q1

Tool/software:

Hi team,

Episodic phenomenon, when sent WUP message to wake up the sleep mode TCAN1145-Q1, there is no level change on RX pin.

We wonder if it gets in the wrong mode, or something go wrong with the software configuration. Can you advise some possibilities about this phenomenon?

over 1 year ago

0 Eric Hackett over 1 year ago

TI__Guru 74292 points

Steve,

What are the voltage levels on VCC and VIO when the wake up occurs? RXD won't toggle if VCC isn't present when a wake occurs. In this case, nINT can be used to indicate the wake event.

Regards,

Eric Hackett

0 Steve Sun over 1 year ago in reply to Eric Hackett

TI__Intellectual 1990 points

Hi Eric,

If VCC isn't present, the INH pin will also go wrong, is that right?

0 Eric Hackett over 1 year ago in reply to Steve Sun

TI__Guru 74292 points

Steve,

The INH pin should still assert to a high state even if VCC or VIO are not supplied.

Regards,

Eric Hackett

0 Steve Sun over 1 year ago in reply to Eric Hackett

TI__Intellectual 1990 points

Hi Eric,

Could you clarify that more clearly? I see that in datasheet, "A UVSUP event causes the INH pin to turn off. "

0 Eric Hackett over 1 year ago in reply to Steve Sun

TI__Guru 74292 points

UVSUP is an undervoltage on the VSUP power input, not VCC or VIO. Since INH is pulled up to VSUP, when VSUP goes under voltage, it turns off. When VCC or VIO are not present, if a wake event occurs to put the device into Standby mode, INH will still assert high.

Regards,

Eric Hackett

Interface

Interface forum

TCAN1145-Q1: Episodic phenomenon, when sent WUP message to wake up the sleep mode TCAN1145-Q1, there is no level change on RX pin.