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Original question:

TPL5110-Q1: How to reset from one-shot mode

TPL5110-Q1: TPL5110-Q1

Christos Apostolidis
Prodigy 120 points
Part Number: TPL5110-Q1
Other Parts Discussed in Thread: TPL5110

Hello, 

I would like to clarify the function of TPL5110 as i have a little confusion in my head.

I read 
7.3.1 ... ... ...When the DRV is LOW, the manual power ON signal is ignored.

7.4.1 ... ... ... Once the reading of the external resistance is complete, the TPL5110 enters automatically in one of the two modes according to the EN/ONE_SHOT value. ... ... ...

Now, i can understand the timer function 

7.4.2 Timer Mode During timer mode (EN/ONE_SHOT = HIGH), the TPL5110 asserts periodic DRV pulses according to the programmed time interval. The length of the DRV pulses is set by the receiving of a DONE pulse from the µC. See Figure 8.

Means, that with EN/ONE SHOT = HIGH & DELAY/M_DRV = connected to ground via REXT then TPL5110 will set DRV to LOW (mosfet is ON) when powered up for the duration of the time setting or until DONE signal received, then will repeat.

If i understand this correctly so far then, here is where i am confused

7.4.3 One-Shot Mode During one-shot mode (EN/ONE_SHOT = LOW), the TPL5110 generates just one pulse at the DRV pin which lasts according to the programmed time interval. In one-shot mode, other DRV pulses can be triggered using the DELAY/M_DRV pin. If a valid manual power ON occurs when EN/ONE_SHOT is LOW, the TPL5110 generates just one pulse at the DRV pin. The duration of the pulse is set by the programmed time interval. Also in this case, if a DONE signal is received within the programmed time interval (minus 50 ms), the MOSFET connected to the DRV pin is turned off. See Figure 9 and Figure 10.

Now please bare with me, this is what i understand.

Upon power on with EN/ONE_SHOT=LOW, TPL5110 will set DRV to LOW (mosfet is ON) for the set time or until a Done signal is received.
BUT

>>>In one-shot mode, other DRV pulses can be triggered using the DELAY/M_DRV pin.
So, if i have a trigger at DELAY/M_DRV pin generating HIGH pulses it will "reset" the timer expanding the current pulse (so in order to keep the mosfet a high M)DRV pin pulse will do the trick?

>>>If a valid manual power ON occurs when EN/ONE_SHOT is LOW, the TPL5110 generates just one pulse at the DRV pin.
I dont understand this .... Does this mean that, in ONE-SHOT mode while mosfet is turned on, an m)drv trigger will not expand the duration of the DRV pulse which has to either return to high on timer setting or DONE signal THEN it can be activated again using m/drv?

In the application i am designing, I would like to have the mosfet ON when powering up, for say 10min expecting a DONE signal.
But i want to implement a function of expanding the 10min window if DONE signal has not be activate for another 10 min and so on... this "Time expansion" signal would be the same as in manual activating the mosfet when in off state. 

Also, if i understand correctly, in ONE SHOT mode, mosfet is on when starting and then goes off either when time has passed or done signal is triggered.
Will it then stay OFF until manually activated with m/drv???? 

  • 0
    TI__Genius 16845 points

    Q1. In one-shot mode, other DRV pulses can be triggered using the DELAY/M_DRV pin. So, if i have a trigger at DELAY/M_DRV pin generating HIGH pulses it will "reset" the timer expanding the current pulse (so in order to keep the mosfet a high M)DRV pin pulse will do the trick?

    A1. See Figure 12 to understand timing for Manual MOSFET Power ON in One-Shot Mode. For a valid M_DRV pulse, you see DRV go low (turn PMOS on) after t_M_DRV. In other words, you can use the M_DRV pin to restart the timer or one-shot, which will pull DRV low and turn on the FET.

    Q2. If a valid manual power ON occurs when EN/ONE_SHOT is LOW, the TPL5110 generates just one pulse at the DRV pin. I dont understand this .... Does this mean that, in ONE-SHOT mode while mosfet is turned on, an m)drv trigger will not expand the duration of the DRV pulse which has to either return to high on timer setting or DONE signal THEN it can be activated again using m/drv?

    A2. See Figure 12. If DRV is low (i.e. the PMOS is turned on), it is NOT a valid M_DRV pulse, so it will not have an effect.

    Q3. Also, if i understand correctly, in ONE SHOT mode, mosfet is on when starting and then goes off either when time has passed or done signal is triggered.
    Will it then stay OFF until manually activated with m/drv???? 

    A3. The MOSFET will be turned on after the resistance reading as shown in Figures 9 and 10. Then, it will be OFF until another DRV is triggered with a valid M_DRV.

    Kind regards,
    Lane