Dear Sir
Can anybody give me advice how to choose and drive power MOSFET with 3.3V MSP430F5438 processor (schematic, parameters)?
Thank you.
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Dear Sir
Can anybody give me advice how to choose and drive power MOSFET with 3.3V MSP430F5438 processor (schematic, parameters)?
Thank you.
Please add a block diagram of what you intend to do with the MOSFET. Include switched voltage levels, etc.
Eric Wright said:Please add a block diagram of what you intend to do with the MOSFET. Include switched voltage levels, etc.
I will try it in attached file DCmotor_MSP430.pdf.
Q1 should have a logic level gate-source voltage so that the MSP430 can directly turn it on/off. Also, place a gate-source resistor (10-100k ohm should be fine) across Q1 so that when the MSP430 is in reset that Q1 is off.
Protect Q1 with a TVS type device across the DC motor (anode on Q1-drain and cathode on +24V). Size the TVS for DC supply maximum voltage and energy required based on motor. Noise may be an issue so a filter between the motor and +24V supply may also be required.
Please, see attached file. Did you think something like this?No resistor or diode resistor combination serial with gate?
What Vg and Vgth?
Thank you
Maybe add a small series resistor between MSP430 and GATE (50 ohms). The selected FET Vgs(th) looks good but the selected FET Vdss is only 24V. You should probably use a 40V FET minimum with a 24V supply/motor.
For MSP430 operating from 3.3V you should review the output logic levels for MSP430 to ensure that Vout(high) min is greater than Vgs(th) max over the operating conditions.
I adapted schematic and changed MOSFET. They do not document Vgthmax. Also Total gate charger is bigger.