Electronics4you
Member
Can a MOSFET IRFZ34 drive a 10A motor with only a 5V/20mA TTL signal on the gate?
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I don't know where you got 6.3 Amps. The IRF datasheet says 30 Amps max, with Ron=0.06 ohms max at 10V. This would be a power dissipation of 6 watts, which would require a heat sink. The problem is you can't do this with TTL drive. You need 10 volts of gate drive.denikar said:The part can provide a max steady state current of about 6.3A at room temperature with Vgs = 10V, so no.
No, the max voltage for the TC426 is only 18V and the Mosfet's gate needs only 10V, so use a 10V supply for the TC426.Electronics4you said:I use a TC426 1.5A Dual High-Speed Power MOSFET driver and a Vdd supply of at least 20V, which should be able to drive at least a 10A motor.
Ron H said:I don't know where you got 6.3 Amps. The IRF datasheet says 30 Amps max, with Ron=0.06 ohms max at 10V. This would be a power dissipation of 6 watts, which would require a heat sink. The problem is you can't do this with TTL drive. You need 10 volts of gate drive.
You may be right, but why would you restrict yourself to no heatsink on a power MOSFET sinking 10 Amps?denikar said:I could be mistaken, but here is where the 6.3A came from:
The junction-to-ambient thermal impedance is listed at 62 C/W with no heatsink. The maximum Rdson at room temperature is given at 50mhm: with a Vgs of 10V.
At room temperature, the part can safely dissipate about 2W with no heatsink (150C - 25C)/(62 C/W).
Imax = sqrt(P/Rdson) = sqrt(2W/50mhm = 6.32A.
The FETs threshold voltage is the lowest voltage on the gate at which the FET will start to conduct. To drive a FET from a TTL gate you'll need a 4K7 pull up resistor and a logic level FET. If it is driven from 5V CMOS logic, no pullup is required. Something like the IRLZ44 will work.Then it can't be directely controlled with a TTL circuit. Is it the threshold voltage (what is that anyway)