Thursday 14 May 2015

arduino - mosfets in h-bridge get hot on idle load


I'm trying to build cheap H-bridge driver to operate under 12-24 input voltage. I used 12v regulator as separated Vgs voltage driver, also to increase load current and I paralleled two MOSFET with each other and separate gate signal, so it is consist 4 P & 4 N MOSFET type. I used NAND Schmitt triggers circuit with Enable, Direction and PWM control as per following image, but when I fabricated the board and connected to 12v power supply and 12v DC motor, under low PWM frequency (450 Hz) which is made by Arduino uno and no load on motor shaft, it's got unexpectedly so HOT. My NAND Schmitt triggers circuit seems has no design problem and I thought pull-push gate drive circuit for P-Mos with enhanced switching speed. I don't know where should I look for this problem. Following is the MOSFET data



  • SSD20P03 P-MOSFET: 24A, -30V, RDS(ON) 59mΩ


  • VGS 20

  • Total Gate Charge 6.4nc

  • Gate-Source Charge 1.9nc

  • Gate-Drain Charge 2.5nc

  • Input Capacitance 520pf

  • Output Capacitance 13pf

  • Reverse Transfer Capacitance 70pf

  • Turn-on Delay Time 10ns

  • Rise Time 2.8ns

  • Turn-off Delay Time 53ns


  • Fall Time 46ns





  • SUB45N03 N-MOSFET: 45A, 30V, RDS(ON) 13mΩ

  • VGS 20

  • Total Gate Charge 40nc

  • Gate-Source Charge 7.5nc

  • Gate-Drain Charge 8nc

  • Input Capacitance 2000pf


  • Output Capacitance 370pf

  • Reverse Transfer Capacitance 180pf

  • Turn-on Delay Time 11-20ns

  • Rise Time 9-20ns

  • Turn-off Delay Time 38-70ns

  • Fall Time 11-20ns




enter image description here




No comments:

Post a Comment

arduino - Can I use TI's cc2541 BLE as micro controller to perform operations/ processing instead of ATmega328P AU to save cost?

I am using arduino pro mini (which contains Atmega328p AU ) along with cc2541(HM-10) to process and transfer data over BLE to smartphone. I...