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I have an IRS2153D configured so that the driver power supply is separate but not isolated from the half-bridge power supply. As soon as I place 12 V across the unloaded half-bridge, the driver bricks itself. Why is this happening? Does it require a load to work properly?

Notes: The voltages being used here are for testing purposes. RVCC was chosen such that the driver is given a maximum current of 16mA which is within spec of the datasheet(5-20mA). Poking the gates of the MOSFETs with an oscilloscope shows there is more than enough dead time to prevent shoot-through, around 750ns or so. MOSFETs are IRFP250N with 2.7Ω gate resistors.

This should be the end of the half-bridge saga. Thanks for your help! half-bridge driver

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  • \$\begingroup\$ What FETs are you using? \$\endgroup\$
    – Frog
    Jan 29 at 0:17
  • \$\begingroup\$ IRFP250N, 2160pF input capacitance, with 2.7Ω gate resistor \$\endgroup\$ Jan 29 at 0:22
  • \$\begingroup\$ Destructs or just locks out? \$\endgroup\$ Jan 29 at 1:15
  • \$\begingroup\$ I checked if it went into UVLO mode by removing all power, discharging all capacitors and repowering it. The driver dies every time. \$\endgroup\$ Jan 29 at 1:35
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    \$\begingroup\$ Are you aware you may need to precharge your bootstrap? Or periodically recharge it by activating the lower MOSFET? \$\endgroup\$
    – DKNguyen
    Jan 29 at 2:33

3 Answers 3

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I formerly worked at IR designing chips... The Gate driver chip has peak current limitations when driving the FET's Gate capacitance... Choose a lower Capacitance FET with descent Rise and Fall times. Then adjust gate resistor (Typically 2 to 10 Ohms) to avoid any over-shoot and ringing.

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  • \$\begingroup\$ I actually solved this problem weeks ago, but this ended up being the exact cause of the whole thing. Thank you for taking the time to write your response and it is so cool that you worked for IR at one point! \$\endgroup\$ Apr 25 at 1:11
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One possibility is that when it switches on, big spike goes through Miller capacitance to the driver. 12V doesn't seem enough to kill, maybe it's current. 24V is almost a guaranteed kill, if only it gets to the gate.

Another thing that worries is the 1.5k resistor. It's possible that voltage on VCC drops very low and you get special effects of current flowing back.

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Lower the value of RVCC. You're starving the chip. The chip alone needs 5mA of current not including switching/bootstrap current; you have 600uA left in your power budget. RVCC should be dissipating around 1W. Source: page 9 of the datasheet. Also, make sure your MOSFETs aren't already shorted.

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  • \$\begingroup\$ 24/1500 is 16mA. That’s very close to it’s maximum input current of 20mA. Am I missing something? \$\endgroup\$ Jan 29 at 17:18
  • \$\begingroup\$ @ElectronicsNoob Yes, you are. The calculation is (24V - 15.6V)/1k5 = 5.6mA. Your calculation is assuming the chip drops no voltage. \$\endgroup\$
    – MOSFET
    Jan 29 at 17:24

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