• State
  • Locked Locked
  • Replies 5 replies
  • Subscribers 62 subscribers
  • Views 1291 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

mosfet for DRV110

Mitchell Solomon
Intellectual 320 points
Other Parts Discussed in Thread: DRV110, UCC27517, CSD17522Q5A

Hi, I started another discussion in another forum,

https://e2e.ti.com/support/applications/motor_drivers/f/38/p/546518/2006065

but I'm stuck now (I think) at finding the right mosfet...
In my application of the DRV110, I'm at 12volts so my Vgs is 12v
and the DRV110 needs a total gate charge of 10nc or less
(where this is in the datasheet i don't know... I'm a mosfet newbie, I'm guessing from the Idrive sink/source currents)

so.. i cant find a mosfet that has 10nc or less and handle my current requirements (at least 16amps)
so i think the answer is a Gate Driver prob the UCC27517 as mentioned in my post
assuming with that it opens the door then for me to use many mosfets as my options...

my MOSFET needs be at least: VDS 60v, ID 16amps, VGS max 20vin my test circuit I have a STP16NF06...
it seems the total gate charge is a little over 10nc
it works, but gets HOT and i can hear the solenoid oscillating


i will be trying a CSD17522Q5A


i assume my connection from the DRV110 to the UCC27517 would be NON-INVERTING
and what would R1 be

  • 0
    Intellectual 320 points

    here is my current schematic, this is for a PCB that is in production now, to use that new mosfet (CSD17522Q5A)
    the one I'm testing with is basically the same, but with a TO-220, so I could use the STP16NF06
    (and others in same case, but again, struggling to find mosfet with low enough total gate charge so the DRV110 is happy)

    thanks
    mitch

  • 0 in reply to Mitchell Solomon
    TI__Mastermind 18200 points

    Mitchell, 

    What makes you think the gate charge needs to be below 10nC? Did the motor drive group confirm that? 

    Also, you said previously that you needed a 60V FET, but this is not the case for 12Vin. As long as the FET has 20V or greater BVDSS, you should be fine. 

    The real question is how much current will the FET itself be driving? Current ratings on FET datasheets are more or less bogus, so the question is how much current are you driving in the application? 

  • 0 in reply to Brett Barr1
    Intellectual 320 points

    yes, the motor group told me that... I'm not sure where it actually comes from...

    yes, I could use a 30v FET... (I wanted safety zone, and don't I get a high voltage spike when the solenoid releases)

    now the current is, about 16amps for 100ms then the drv switches to PWM and current goes down to less than .500ma

    right now... it works, but the FET gets dam hot during the PWM cycle, when less than .500ma flowing

    if I keep the solenoid engaged it will burn up!

  • 0 in reply to Mitchell Solomon
    TI__Mastermind 18200 points
    Hmm, I am not familiar with the driver. But if the FET is overheating at so little current, this sounds like a system issue. Definitely not from conduction losses at only half an amp with the CSD17522Q5A
  • 0 in reply to Brett Barr1
    Intellectual 320 points
    well right now I'm testing with the STP16NF06...

    the next pcb I get, it will be the CSD17522Q5A

    so... is the gate charge in question??
    in an example board you guys made (tidu578)
    and that's a 100v 4amp FET, FDMC8622 (gate charge of 5 to 7ish at 10vgs)

    mitch