TCAN1043A-Q1: Sleep mode

Kanava Sait Abdul Kathar

Part Number: TCAN1043A-Q1

After power up, Is there a way to move this device to sleep mode directly, not going to standby mode which drives INH high.

over 2 years ago

0 Eric Hackett over 2 years ago

TI__Guru 74292 points

Kanava,

Unfortunately no, even if both EN and nSTB are in the states that would put the device into sleep mode at power up, it will still first go into standby mode, then immediately transition to sleep mode.

Please let us know if you have any other questions.

Regards,

Eric Hackett

0 Kanava Sait Abdul Kathar over 2 years ago in reply to Eric Hackett

Prodigy 60 points

Eric Hackett, Thanks.

Just to be clear, INH will be high after power up (i.e only Vsup > UVsup) even if VCC & VIO are not present (i.e VCC < Uvc & VIO < UVio).

0 Kanava Sait Abdul Kathar over 2 years ago in reply to Kanava Sait Abdul Kathar

Prodigy 60 points

Also, how long it would be in standby mode after power up?

0 Eric Hackett over 2 years ago in reply to Kanava Sait Abdul Kathar

TI__Guru 74292 points

Kanava,

Yes that is correct. And if the EN and nSTB pins are configured for sleep mode after power up, the device should transition to sleep mode from standby mode ~35us after INH is asserted.

Regards,

Eric Hackett

0 Kanava Sait Abdul Kathar over 2 years ago in reply to Eric Hackett

Prodigy 60 points

Thanks, I probed INH & Vsup in the EVM board. INH always stayed high, It didn't go low after 35us.

In this setup, only Vsup was connected, no VIO & VCC. Also I added jumper for EN (low) & nSTB (low).

0 Danny Bacic over 2 years ago in reply to Kanava Sait Abdul Kathar

TI__Mastermind 26826 points

Kavana,

Have you connected any sort of pull-down or load to INH? Note that INH does not pull strongly to GND. It can only either pull high to VSUP or be high-impedance.

When VCC and/or VIO are undervoltage, the device is in sleep mode regardless of the states of the EN and nSTB pins. This makes INH high-impedance. See Table 8-4 for reference.

Best,

Danny

0 Kanava Sait Abdul Kathar over 2 years ago in reply to Danny Bacic

Prodigy 60 points

Danny, No I didn't connect any pull-down to INH pin. My observation is not matching with table 8-4. I think after power up (if STB & EN are low) it stays in standby mode.

0 Kanava Sait Abdul Kathar over 2 years ago in reply to Kanava Sait Abdul Kathar

Prodigy 60 points

Erick, Can you pls clarify this?

0 Eric Schott1 over 2 years ago in reply to Kanava Sait Abdul Kathar

TI__Guru 53575 points

Hi Kanava,

When TCAN1043A first powers on (Vsup > UVsup), an internal wake request flag is set that will prevent the device from going directly into Sleep mode. To clear this flag, the device needs to be placed into Normal mode (EN = nSTB = high). After this, the device may be place into Sleep mode via go-to-sleep mode (EN = high, nSTB = low). After 20 - 50us in this state, Sleep mode will be entered and the INH signal will move to a high impedance state.

Alternatively, if the transceiver stays in Standby mode for ~4 minutes, the Sleep Wake Error timer (SWE) will time out and the device will automatically move to Sleep mode.

Regards,
Eric Schott

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TCAN1043A-Q1: Sleep mode