1
\$\begingroup\$

Using a 3.3V (max. 8 mA) output pin off an Intel Galileo development board, I need to turn on and off a 18V DC motor. Is it better to use a JFET or MOSFET transistor?

\$\endgroup\$
2
  • 1
    \$\begingroup\$ What are you metrics for "better"? \$\endgroup\$
    – PlasmaHH
    Aug 10, 2015 at 14:46
  • \$\begingroup\$ You can as well use 2 BJTs, connected as a Sziklai pair. 3.3V is a little low for driving a MOSFET; you'll need to use one that has low Rds at this gate voltage. \$\endgroup\$
    – ilkhd
    Aug 10, 2015 at 17:56

1 Answer 1

3
\$\begingroup\$

I doubt that a JFET will be able to adequately control a motor without significant power losses due to it's likely high on resistance. MOSFETs, on the other hand, are extensively used for controlling DC motors and power-hungry loads.

The best JFETs I've seen might just about get as low as a few ohms whereas I've seen MOSFETs that are that value divided by 1000. Also, JFETs tend not to be rated at voltages in excess of 30V.

A JFET, as a generalism, is not suited for motor power control.

\$\endgroup\$

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.