1
\$\begingroup\$

I have some trouble about my MOSFET and its driver. I wanna operate my circuit around 4-5 Amps peak. For this purpose I drive two IRF540N MOSFETs parallel with one TC4427 driver by 62.5kHz PWM. But my MOSFETs are getting too hot. I checked related issues, maybe I using fake MOSFETs. I added my schematic. Any suggestions ?

Thanks in advance

enter image description here enter image description here

\$\endgroup\$
  • 2
    \$\begingroup\$ You do not appear to have any load? \$\endgroup\$ – Trevor_G Dec 5 '17 at 19:03
  • 1
    \$\begingroup\$ Then show it in the schematic and show exactly how it's connected. \$\endgroup\$ – Finbarr Dec 5 '17 at 19:10
  • 1
    \$\begingroup\$ And what are you driving this with? \$\endgroup\$ – Trevor_G Dec 5 '17 at 19:16
  • 2
    \$\begingroup\$ I still don't see a schematic showing the load. \$\endgroup\$ – Finbarr Dec 5 '17 at 20:25
  • 1
    \$\begingroup\$ What do your waveforms look like...You do have a scope right? \$\endgroup\$ – Trevor_G Dec 5 '17 at 21:15
1
\$\begingroup\$

Examine the datasheet for TC4427, and you'll see some hysteresis in the "schematic". A hysteresis of 0.3 volts is not a strong barrier to oscillation, when 1.5 amps/15nanoseconds thru 10nH produces ONE VOLT of ground bounce.

Build this combined circuit ONLY ON A GROUND plane.

Have the high voltage bypassed to the GROUND PLANE; ONLY TO THE GROUND PLANE; do not share any return paths between the high voltage and the MCU VDD or GND.

Just some thoughts, from someone who understands how to make FETS and FET drivers self-destruct.

\$\endgroup\$
1
\$\begingroup\$

Thanky you all for your helpful comments, today I solved my problem that is about my power supply's ground. Before, I combined all the grounds at my MOSFETs source pin (mcu, drivers ground, and MOSFETs source). So, I observed, drivers OUT pins hasn't enough voltage (around 4Volts) for drive MOSFETs properly. Then my MOSFETs are getting hot. Today, I seperate the ground pins (MCU and Driver together, and MOSFETs), then driver's OUT voltage (which is equal to Vgs) became 9Volts and MOSFETs working properly now without heat.

Thank you for your time and comments.

\$\endgroup\$
  • 1
    \$\begingroup\$ thank you for posting the fruits of your experience. Could you please draw before/after diagrams of your wiring, showing the changes you made that resolved the problem? \$\endgroup\$ – danmcb Jun 28 '18 at 15:35

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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