TCAN1043A-Q1: Sleep wakeup control through remote wakeup -INH pin

DARSHAN M M V

Part Number: TCAN1043A-Q1
Other Parts Discussed in Thread: TCAN1043

Tool/software:

Hello team,

1. from the data sheet I have observed , when using a remote wakeup capability specific pattern of CAN frames needs to be put in CAN bus to make INH high - is this assumption is true or TCAN1043 will make INH high for any bus activity

2.Referring to the above block diagram,lets assume initially INH is low and system is completely turned off since no 5V output , If I want to put my system back to normal mode , I have to INH high to turn on the buck converter, i order to do so by remote wakeup , if CAN bus experience any signal will my INH will go high ? if not what is the constraint have to be followed w.r.t CAN frames.

3.assume now the system is in normal mode, I have to make INH low to cut down the power to the entire system so that system is in completly sleep mode , so what is procedure or sequence has to be followed w.r.t Stb pin and EN pin in order make INH low .

4. system has either completely turned off - sleep mode or should be normal mode - this is our expect ion that has to achieved through CAN INH signal.

Please provide the solution for the above queries

9 months ago

0 Ethan Sempsrott 9 months ago

TI__Genius 13322 points

Hi Darshan,

1. Yes, your assumption is correct. Only a specific wake-up pattern must be on the bus to bring the device from Sleep to Standby (bringing INH high). Section 8.4.1.5.1 in the datasheet describes this pattern defined by the ISO11898-2:2016 standard.

2. If the device is in Sleep mode and you want it to turn INH high for the buck, then either a wake-up pattern (WUP) or a local wake event (LWU) must be detected. The WUP is described above, and the LWU is triggered by the WAKE pin as described in Section 8.4.5.2 in the datasheet.

3. The fastest way to enter Sleep mode (which turns INH low) is to turn off VCC or VIO. If your MCU controls VIO, then this method could be used. Otherwise, EN = High and nSTB = Low, and this will begin the process for TCAN1043A to enter Sleep mode. These modes are outlined by the state machine in Figure 8-4.

4. I do not understand this 4th question. Could you clarify this question and what you mean by "completely turned off"? By completely turned off, do you mean the device is in Sleep mode with VCC and VIO off, or do you mean that VSUP is off?

Best,

Ethan

0 DARSHAN M M V 9 months ago in reply to Ethan Sempsrott

Intellectual 265 points

Hello Ethan,

answering to the 4th Question ,

Could you clarify this question and what you mean by "completely turned off"?- we have to make INH low so that buck converter will not generate the output voltage so that Vio and VCC will get the voltage

+1 Ethan Sempsrott 9 months ago in reply to DARSHAN M M V

TI__Genius 13322 points

Thank you. This means the device has VSUP on and is in Sleep mode. A WUP or LWU will wake the device and enter Standby mode setting INH high. Does this answer your last question?

0 DARSHAN M M V 9 months ago in reply to Ethan Sempsrott

Intellectual 265 points

Hello Ethan,

what are the design parameters I have to consider in the schematic level to pass the CCC and DCC test -ISO 7637-3 transient on signal lines.

Can you please share me the EMC report if you would have performed this

0 Ethan Sempsrott 9 months ago in reply to DARSHAN M M V

TI__Genius 13322 points

Hi Darshan,

A common mode choke should be added to the design to pass the EMC tests.

I will share the EMC report via the email listed on your E2E account.

Best,

Ethan

0 Ethan Sempsrott 9 months ago in reply to Ethan Sempsrott

TI__Genius 13322 points

I just sent you the email.

Additionally, the document below is a helpful guide to picking a CMC for whatever CAN device you are using:

https://www.ti.com/lit/an/slla271/slla271.pdf

0 DARSHAN M M V 9 months ago in reply to Ethan Sempsrott

Intellectual 265 points

Hello Ethan,

1 . Referring to the above block diagram which I captured from data sheet , If I want use remote wakeup through CANH and CANL ,whether the VCC supply 5V has to be supplied? or even if 5V does not exist , whether the remote wakeup is possible?

2 . once the TCAN1043 is wake up through remote wakeup , it will make INH high - my question is whether the INH is a pulse ( it will be high only for some time) or it will be high for all time once it is woken up?

Please consider this as high priority and provide the feedback as early as possible

0 Ethan Sempsrott 9 months ago in reply to DARSHAN M M V

TI__Genius 13322 points

Darshan,

I apologize for the delay as we just returned from holiday.

1. VCC is not required for WUP or LWU.

2. INH is not a pulse, and it will stay high. This assumes that the device does not enter back into Sleep mode.

Best,

Ethan

0 DARSHAN M M V 9 months ago in reply to Ethan Sempsrott

Intellectual 265 points

Hello Ethan,

Whether the VIO is required for remote wakeup?

+1 Ethan Sempsrott 9 months ago in reply to DARSHAN M M V

TI__Genius 13322 points

VIO is not required to detect WUP or LWU. Once WUP or LWU is detected, INH will go high which should eventually turn on VCC and VIO.

0 DARSHAN M M V 9 months ago in reply to Ethan Sempsrott

Intellectual 265 points

Hello Ethan,

Can please explain this Wakeup pattern is which part of CAN frame ?, Please refer the snapshot

0 Ethan Sempsrott 9 months ago in reply to DARSHAN M M V

TI__Genius 13322 points

Hi Darshan,

The best way to learn about this wakeup pattern is to refer to Section 8.4.1.5.1 of the datasheet. There it has the full explanation with diagrams to illustrate the timings.

Best,

Ethan

Interface

Interface forum

TCAN1043A-Q1: Sleep wakeup control through remote wakeup -INH pin