Need help driving two IPS1031 Low-Side MOSFETs from a PIC

Discussion in 'General Electronics Chat' started by JedOs, Aug 11, 2006.

  1. JedOs

    Thread Starter New Member

    Aug 11, 2006
    4
    0
    The IPS1031 is a Low-Side MOSFET Driver that drives its own MOSFET. I am planning on incorporating it into my design, but most of its spec sheet is total gibberish to me.
    I am driving two of them off of a single PIC output which can sink 3.7-5V @ 25mA.
    The IPS1031 datasheet: http://www.irf.com/product-info/datasheets/data/ips1031.pdf

    Attached is a schem I used for its simulations purposes. Through the use of "OR" diodes, only two IPS1031s are on at any single time; Q2 is saturated when either Q1 or Q3 is saturated. S1 and S2 signafy two different PIC Outputs.
     
  2. mrmeval

    Distinguished Member

    Jun 30, 2006
    833
    2
    You seem to have it covered. Why the 4.7k reistor from input to ground?
     
  3. JedOs

    Thread Starter New Member

    Aug 11, 2006
    4
    0
    The PIC internally pulls-down to grnd, but the sim needed these resistors to emulate a pull-down.
     
  4. JedOs

    Thread Starter New Member

    Aug 11, 2006
    4
    0
    LMAO, I forgot to mention what it was that I needed help on. I was concerned about the required voltage to turn on the mosfet, and if in combination with the diode and the pic output, if it would even see this voltage.
     
  5. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    jedos,

    The ips1031 datasheet indicates that it could require as much as 5.5V on its input to turn on. The PIC output by itself would at best provide a maximum of 5V at its output. This falls short of the maximum of 5.5V required. The added voltage drop of the 1n5282 will further reduce the likelihood of reliably turning on of the ips1031. All this being said, the PIC may enable the ips1031 but it would be hard to say absolutely that the device would switch with 100% certainty every time.

    hgmjr
     
  6. JedOs

    Thread Starter New Member

    Aug 11, 2006
    4
    0
    Yeah, I decided to not use the IPS1031 and instead use an NPN transistor like the 2N4401, and then perhaps use it to amplify for a MOSFET, but I may just stick with the transistors. Perhaps you have any other suggestions?
     
  7. mrmeval

    Distinguished Member

    Jun 30, 2006
    833
    2
    The datasheet says 4.5 volts is the minimum needed. You'd have to test to see if that is the case. If that does not work you could borrow the 12V supply and regulate it down to the right voltage needed then use a transistor which is switched on/off by the PIC.

    LM317T would work to regulate that.

     
Loading...