Original question:
If EN pin controlling the VDRV Pin which implies as long as EN pin is high, VDRV will be high which will drive the back-to-back MOSFET Connection.
If my understanding is correct the bootstrap capacitors CDIV1 and CDIV2 are boosting the voltage. How long the capacitor can maintain the boosted voltage.
I have a use case where the MOSFET will have to be turned ON continuously for 6 - 7 days. Will the device TPSI3050 work for my use case.
Hello Arun,
Thanks for joining E2E and reaching out to our team!
We can model switching a MOSFET as charging and discharging a capacitor (CVDRV), the value is determined by the total gate charge (Qg) divided by the driver voltage (VDRV). Every time we turn on the MOSFET, this is the same as charging up CVDRV to 10 V. Every time we turn off the MOSFET, we discharge CVDRV.
When the TPSI305x-Q1 drives VDRV high, it basically connects VDDH to VDRV. When the TPSI305x-Q1 drives VDRV low, it pulls VDRV to VSSS. The peak source and sink currents (1.5A/3.0A) can approximate what the internal resistance looks like for pullup/pulldown.
When you first power the device, the power transfer charges CDIVx. When you turn the driver on, it charges CVDRV via CDIVx. The voltage of CDIVx drops since all the charge must be shared with CVDRV. Then, the power transfer needs to replenish the charge in CDIVx. The voltage drop is shown as droop in the calculator tool. So turning the MOSFET on once for 6 seconds, 6 days, or 6000 days, all requires the same amount of charge.
I have a use case where the MOSFET will have to be turned ON continuously for 6 - 7 days. Will the device TPSI3050 work for my use case.
Yes, just need to sufficiently size CDIVx.
Best regards,
Tilden Chen
Solid State Relays | Applications Engineer
