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What do you look for in a MOSFET driver before choosing it to switch a certain MOSFET? Am reading through the driver datasheet and cant precisely understand what is the ability limit of this driver.

For example, am using a BUK7K89-100E (100V, 13A dual n-channel mos) in a full-bridge circuit.

Trying to figure out if the MIC4606 driver can actually switch it. The driver receives a PWM signal from a µ-controller to switch on and off.

Switching frequency max= 20kHz. Driver supply voltage =12v. Mosfet supply (Drain) voltage = 24V.

Any guidelines that are recommended for this type of process?

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    \$\begingroup\$ What switching frequency are you looking for? Supply voltage (logic and power)? Does it need to be fully static, or can it be bootstrap? \$\endgroup\$ Jun 20, 2022 at 15:51
  • \$\begingroup\$ Switching frequency max= 20kHz. Driver supply voltage =12v. Mosfet supply voltage = 24V. Not clear if it needs to be full static or bootstrap. \$\endgroup\$
    – Elektroneu
    Jun 21, 2022 at 6:35

2 Answers 2

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It all depends on how quickly you need to switch the FETs.

The BUK7K89-100E requires about 5 nC of gate charge. This is (very approximately) 1000 pF. The MIC4606 can drive 1000 pF in 20 ns. If this is sufficient for your switching speed, it will work.

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  • \$\begingroup\$ Thank you jp314. Any guide lines that you would recommend? \$\endgroup\$
    – Elektroneu
    Jun 20, 2022 at 15:43
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    \$\begingroup\$ 13.6nC (total)? At Vgs(on) = 10V, this is effectively an "average capacitance" of 1.36nF. Using an average equivalent, or the charge, always seemed reasonable to me. \$\endgroup\$ Jun 20, 2022 at 15:51
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What do you look for in a MOSFET driver before choosing it to switch a certain MOSFET?

  • Do I really need a MOSFET driver? Can a totem-pole be suitable instead?
  • What do I need? A half-bridge or a single-ended driver?
  • Do I need isolation? Can I use a gate drive transformer or should I go for isolated gate drive chip?
  • (For half-bridge drivers) Can the driver chip generate dead times or should I manage dead time generation externally? (Not always a reason for preference but sometimes it's needed)
  • What is the maximum switching frequency? What rise and fall times are acceptable?
  • (Most important part) What peak current do I need? Can the pre-driver in the driver chip withstand these peak currents during switching?
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