Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

[SOLVED] MOSFET turn on and turn off transients

Status
Not open for further replies.
A

abc_de

Full Member level 5
Joined
Jan 9, 2014
Messages
243
Helped
11
Reputation
22
Reaction score
11
Trophy points
1,298
Location
Ludhiana ਪੰਜਾਬ
Activity points
2,939
Hello
I am working on 3 phase motor control by V/F control.
my circuit consist microcontroller > IR2110> IRF640.
Pwm freqency is 1KHZ
Design is non isolated
my problem that while MOSFET switch on and switch off it create posivite and negative spikes upto +/- 25volts resultant +5v and +15 for microcontroller and ir2110 contant spikes or transient how I can eliminate this

- - - Updated - - -

1,123 IMG20170117193245.jpg

- - - Updated - - -

1,123IMG20170117193245.jpg

- - - Updated - - -

positive and negative transients at +5v power supply

IMG20170116173904.jpg
 
Last edited:

Hi,

Let´s see what informations you gave:
* 3 phase motor --> this will most likely not cause the problem
* motor control --> we don´t see it
* microcontroller --> we don´t see which one. We don´t see it´s connections. We don´t see it´s code....
* IR2110 --> We don´t see it´s connections. We don´t see the PCB layout. ....
* IRF640 --> We don´t see it´s connections. We don´t see the PCB layout. ....
* scope pictures --> we don´t see where and how you connected the scope..

Do you recognize that it is impossible to help you with the given informations?

I even doubt that the transients really exist... I assume it is just a measurement problem. But how can i know?

Klaus
 

hello
thanks for response
i have solve the problem. actually gate resistance was too low which may cause of high dV/dt and negative current coming from motor.
i increase the value of gate resistance which limit the gate current also remove negative and positive transients at gate of mosfet.
another change was use of TVS diode (Bidirectional) +/-18v AT gate of mosfet which completely remove the transients from gate hence net power supply of driver and micocontroller.
also i change the dead time of high and low rail mosfet.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top