LMG1205: Bootstrap capacitor replacement

Art Mecina

Part Number: LMG1205

Hello guys,

How critical is the bootstrap capacitor rating for the LMG1205? Our customer initially had 0.47 MICROFARAD 25 Volt cap. The chip was turning off at lower Temp and at lower frequency, so he had to change the capacitors to 2.2 micofarad, however he only have the 16 volt rating. Is this okay as a replacement?

Thanks and regards,

Art

over 4 years ago

0 Leslie Marquez over 4 years ago

TI__Genius 9451 points

Hi Art,

Thank you for your question. The HB-HS abs max voltage is 7V, so a 16V rating in the bootstrap capacitor is OK. If they change the bootstrap capacitance please make them aware that the VDD capacitance should be at least 10 times greater than the bootstrap capacitance. You can point them to this apps note that guides the customer on how to select each of the bootstrap circuit components based on the FET and components they are using: https://www.ti.com/lit/an/slua887/slua887.pdf?ts=1633535273454&ref_url=https%253A%252F%252Fwww.ti.com%252Fsitesearch%252Fdocs%252Funiversalsearch.tsp%253FlangPref%253Den-US%2526searchTerm%253DBOOTSTRAP%2BCIRCUITRY%2526nr%253D2793

Best regards,

Leslie

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LMG1205: Bootstrap capacitor replacement