0
\$\begingroup\$

My micro-controller is giving a PWM output of 1.8V. I need to drive a MOSFET with typical gate voltage of 3.3V. I am planning to use two cascaded switches (NOT gate configuration). I have checked checked following IC.

  1. TLP250:- minimum supply voltage should be 10V (I can only use 3.3V)

  2. IR2110:- Logic '0' input voltage is between 0-6V. (Maximum available i/p voltage is 1.8)

  3. TC427:- minimum input voltage for logic '1' is 2.4 V (Maximum available i/p voltage is 1.8)

Is there any commercially available IC suitable for my application?

\$\endgroup\$

closed as off-topic by Nick Alexeev, Matt Young, Chetan Bhargava, Daniel Grillo, Joe Hass Mar 11 '14 at 11:22

This question appears to be off-topic. The users who voted to close gave this specific reason:

If this question can be reworded to fit the rules in the help center, please edit the question.

  • 2
    \$\begingroup\$ What will be the switching frequency? What's the model of MOSFET, whose gate you need to drive? \$\endgroup\$ – Nick Alexeev Mar 9 '14 at 19:57
  • \$\begingroup\$ Your description is kind of confusing, can you post a schematic or diagram and the loads and voltages involved. \$\endgroup\$ – alexan_e Mar 9 '14 at 20:07
3
\$\begingroup\$

You could use a BJT as a gate driver.

schematic

simulate this circuit – Schematic created using CircuitLab

\$\endgroup\$
  • \$\begingroup\$ The single stage driver you present inverts the control signal, and based on the description of the OP (I am planning to use two cascaded switches (NOT gate configuration)) this is unwanted. This can be prevented of course by using two common emitter stages, and this seems to be what the OP had in mind. \$\endgroup\$ – alexan_e Mar 11 '14 at 10:11
  • \$\begingroup\$ @markt Hi! I have different values: my micricontroller can drive in digital output 3.3V, I have a mosfet (like RFP30N06LE) and an optocoupler 4N25. How can I calculate the resistor values? Also, is it possible to use 4N25 or I need another transistor? \$\endgroup\$ – nkint Dec 22 '14 at 20:04
  • \$\begingroup\$ @nkint the resistor values I suggested are quite arbitrary. You need to find out how much current you have to supply to the MOSFET gate in order to switch it at whatever speed you need. Your question is far too complicated for a comment, and in any case you need to submit your own question, explaining exactly what you are trying to do, preferably with a circuit diagram. \$\endgroup\$ – markt Dec 22 '14 at 23:33
  • \$\begingroup\$ @markt ok thank you anyway, I will probably post a new question in the next days. \$\endgroup\$ – nkint Dec 23 '14 at 10:46
2
\$\begingroup\$

If you don't need to switch the MOSFET too quickly, you could use a SN74LVC1T45.

enter image description here

In your case, \$V_{CCA}\$ could be 1.8V and \$V_{CCB}\$ could be 3.3V, and you'd tie the DIR line high. It will drive tens of mA from the output, which may or may not be enough to switch your MOSFET as fast as you need.

If it's not fast enough, you could cascade it with an inverter made from something like a FDG6332C dual complimentary pair (but then you'd need another stage of inversion if you wanted no inversion through the signal path).

I don't see much in the way of purpose-built fast MOSFET gate driver chips that are designed to work even at 3.3V.

\$\endgroup\$

Not the answer you're looking for? Browse other questions tagged or ask your own question.