MP5035 Slew Rate Limit

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1

Greetings,

I’m attempting to use an MP5035 as a load switch with high slew rate, as I am targeting a controlled rise of 12V over about 10µs. In my current breadboard setup I am using a 150pF capacitor on the DV/DT pin to achieve that, though the rise time is about 130µs. Switching to a 22pF slightly decreases that rise time by a couple microseconds.

I largely suspect it’s my selection of breadboard that is limiting my slew-rate, but I wanted to check to see if there is a limit on the MP5035 that I might have missed. Is there a minimum capacitance value for DV/DT that provides a max for slew rate? If so, is there a similar component that has faster slew rate capabilities?

Thank you,

Frank

2

Hi @frank.wangberg ,

Using equation 4 from datasheet with your desired slew rate of 12V/10us (1200V/ms) will yield 0.1625nF (162.5pF), so you’re correct with choosing 150pF capacitor as the closest standard value.

Regarding minimum slew rate for the device, there’s no information about the fastest possible slew rate utilizing capacitor on dv/dt pin, but it’s definitely possible that excess parasitics from your breadboard + through-hole components + physical wires is slowing down your slew rate. You can use our MP5035 eval board to test with efficient layout and less parasitics.

Thanks,
Rubas