I have a few questions about the LTM8055. The LTSPICE demo circuit for parallel LTM8055 found here https://www.analog.com/en/products/ltm8055.html#product-tools shows a large voltage overshoot on startup and very high current demands from the modules. Is this realistic of the modules in a parallel configuration or is this a simulation artifact? The datasheet doesn't mention anything about parallel startup being a problem. The single device LTSPICE model doesn't have this problem. The simulation is for a 12V output and the voltage goes to almost 24V before settling.
Unrelated to the simulation, does the device have short circuit protection in all modes of operation (buck and boost)? Do I need to do anything special for parallel devices for fault protection? Do they have any circulating problems during faults?
Hi, here's the result of the startup test of LTM8055 in parallel configuration with 24V input (Blue), 12V output (pink), and 12A load (green). The result shows unnoticeable overshoot in the output voltage…
Did you get a chance to look into the parallel overshoot? Is it just a simulation issue? I've noticed that the LTspice model is different than the parallel model on page 20 of the datasheet. The datasheet shows a capacitor on the compensation pin. I modified the LTspice model to match the datasheet but still the same problem. Also, I don't see where the datasheet explains the compensation for the control.
I have the same problem but with LTM8056.
If you have an update please let me know. We are planning to place a Load Switch if it really occurs on the board .
With best regards and wishes
Hi, we are looking into this and will get back to you after the holidays.
Hi, here's the result of the startup test of LTM8055 in parallel configuration with 24V input (Blue), 12V output (pink), and 12A load (green). The result shows unnoticeable overshoot in the output voltage.
Take note that I have used two DC2017A evaluation board for this test. One working as a master and the other one working as a slave. Make sure to make the connections of Imon, CTL, SYNC, CLKOUT, and GND as close as possible to avoid noise interference in the circuit. There is also a provision for LT1636 isolator in the evaluation board of LTM8055, so you don't have to make another board for it.