• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 23 subscribers
  • Views 1081 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPL5111: Reset time period.

yunsong sim
Intellectual 270 points

Part Number: TPL5111
Other Parts Discussed in Thread: TPL5010

I would like to use this timer for the periodic action. 19mins will be hibernation mode and 1min working mode  with 20mins period.

Normally, MCU will be awakened by itself using an internal timer. Nevertheless, I want to add this time for redundancy.

So, I will set the time with 19mns 30secons to output DRV signal to the interrupting pin of MCU to wake. 

If MCU is awakened well, it can be ignored the signal. If not, MCU can be awakened by this signal.

After working all procedure by MCU, timer needs to be reset its time interval again.

I think M_DRV pin will be for this purpose. 

Am I right? Is there anything to be considered to using this concept?

Thanks a lot.

  • 0
    TI__Expert 4415 points

    Hi Yunsong,

    It is possible to use M_DRV to reset the time interval- however, it is complicated because pulling M_DRV high is a manual power on signal and tells the device to pull the output DRV signal high, when you really want the output to be low since the microcontroller has just finished. The MCU will have to ignore this DRV high pulse that happens immediately after using M_DRV, or it will need to issue a DONE pulse to stop this first pulse.

    Additionally, M_DRV is ignored if DRV is already high- so if your MCU finishes the procedure before DRV goes low, it needs to first pull DRV low by issuing a DONE pulse, before performing the above procedure to use M_DRV to reset the time interval. Finally, you will need to account for the timing of both of these procedures to make sure that the timing remains consistent regardless of how long the MCU processing time is.

    In this situation I would recommend using TPL5010 instead- it is a similar part with slightly different functionality that makes it much easier to use. In general, TPL51xx are timers intended for use as MOSFET drivers, whereas TPL50xx parts are meant for digital control, for example, with MCUs like in this case.

    Instead of M_DRV, TPL5010 has a M_RST pin which resets the time interval without pulling WAKE high. It then waits for a DONE pulse in the waiting time interval to make sure the MCU is ready before pulsing the WAKE output:

    (image from pg 10 of datasheet)

    So, to have MCU reset the time interval, it has to assert M_RST, then assert a DONE pulse. Then, it can power down and wait for the WAKE pulse (or use it's internal timer).

    Regards,

    -Tim