Hi Team,
How to design MCU and external switch to control TS/MR pin at the same time? Is there any suggested reference design?
Hi Kevin,
If you are only looking to control the TS/MR pin from an MCU- you can use the circuit below which has an NMOS driving the TS/MR pin low to mimic a button press.
If you are actually using a button and would like for the MCU to read the pin status, you can use the wake timers or a circuit described here in this post- LINK
Let us know if you have any questions.
Regards,
Gautham
Hi, Gautham,
To use the NTC monitor, the Vts could be as low as 0.1V as below table.
Can it still works as a button(Reset function) in the meantime?
Cause when I press the button, the voltage is close to 0V, still very close to 0.1V.
is that mean if the voltage is lower than 90mV, then it detects a button press?
but in this condition, it below 90mV
Hi Heath,
Good question- the typical value for the push button detection threshold is 70mV compared to 97.5mV for the Hot threshold (hot threshold min is actually 95mV). These two thresholds are tracking each other which means a device with high hot threshold will have a high push button threshold voltage as well. What is missing in the datasheet is the minimum threshold where the device sees a button being pressed which is 65mV. Rather the button has to be held lower than 65mV to see an active press event instead of a hot condition. We will update the datasheet to reflect the min value as well. Below is a plot of the NMOS pulling the TSMR pin low.
Let us know if you have any questions.
Regards,
Gautham
Hi, Gautham,
I want to know what's the typical behavior of the TSMR pin when being connected to an NTC & button.
1. ex. if it's 65°C now, the VTSMR sould be ~0.0975V, and when the button is pressed: the VTSMR shall be lower than 65mV, so it could be seen as an active press event. is that right?
2. I'm not sure if I missed something in the datasheet, why is the VTSMR keep toggling here?
Thank you!
