LTC2955-2 Questions

Hi ENGsarah ,

It sounds like you’re working on an interesting project with the LTC2955-2! Here are some clarifications based on your questions:

1. Q1 and Q2 Usage: Q1 is used to control the voltage level at the /KILL pin, simulating the behavior of the /EN output. Q2 emulates a power supply, turning on to power the load when /EN is asserted low.

2. Turning Off LTC2955-2: You can turn off the LTC2955-2 by pressing a button, through a falling edge at the ON pin, or by pulling /KILL low. The /KILL pin provides an immediate shutdown mechanism, useful for firmware shutdowns.

3. Using /KILL Pin: If you don’t intend to use the /KILL pin, pull it up to your power supply or an external supply (1.2V~5V). If you do intend to use it, drive the logic at the /KILL pin using your microcontroller.

4. /KILL Pin Function: The /KILL pin is an input pin that checks the voltage level of the connected signal. If the voltage is above 0.8V, /EN will not deassert. If it goes below 0.8V, /EN will deassert high.

5. Effect on microcontroller: No, it will not affect the microcontroller.

6. TMR Pin: Correct. The TMR pin configures the additional turn-off debounce time.

7. Switch Functionality: A regular switch pulling /PB to GND when pressed should work the same as shown in the simulation.

8. Voltage Regulator Information: Could you provide more details on the voltage regulator you’re using and how you’re integrating it with the LTC2955-2?

Best,

Gaell

Hello @Gaell ,

Thank you so much for taking the time to answer my questions!! Your answers have cleared up a lot of my doubts.

As for question 8, when I used simple voltage regulators such as LT1587-3.3 and ADM7150-3.3, the simulation gets completed up till the stop time that I put.

For the more complex voltage regulators such as ADP2303 and LTC3605, the signals in the graph stop at about 1.24s and don’t continue although the simulation is still “simulating” and hasn’t actually finished up till the required stop time but the graph freezes at this point (1.24s).

As for my connections, I used the example circuit for all the regulars.

Also I have connected the OUTPUT (after the output capacitor -C3 in the example circuit-) of the LTC2955-2 to Vin of the regular.

Best regards,

Sarah

Hello @Gaell ,

Thank you so much for taking the time to answer my questions!! Your answers have cleared up a lot of my doubts.

As for question 8, when I used simple voltage regulators such as LT1587-3.3 and ADM7150-3.3, the simulation gets completed up till the stop time that I put.

For the more complex voltage regulators such as ADP2303 and LTC3605, the signals in the graph stop at about 1.24s and don’t continue although the simulation is still “simulating” and hasn’t actually finished up till the required stop time but the graph freezes at this point (1.24s).

As for my connections, I used the example circuit for all the regulars.

Also I have connected the OUTPUT (after the output capacitor -C3 in the example circuit-) of the LTC2955-2 to Vin of the regular.

Best regards,

Sarah