IR2109SPBF Frequently Asked Questions (FAQs)

• What is the maximum voltage rating of the bootstrap capacitor?
  The maximum voltage rating of the bootstrap capacitor should be at least 2x the maximum voltage of the high-side supply (VCC) plus the maximum voltage of the low-side supply (VIN). Typically, a 25V or 30V rated capacitor is recommended.
• How do I ensure proper bootstrap capacitor charging?
  To ensure proper bootstrap capacitor charging, make sure the high-side FET is turned off before the low-side FET is turned on, and the bootstrap capacitor is connected between the VB pin and the VS pin. Also, ensure the bootstrap capacitor is properly sized and has a low ESR.
• What is the recommended deadtime between high-side and low-side FETs?
  The recommended deadtime between high-side and low-side FETs is typically around 100-200ns to prevent shoot-through currents. However, the optimal deadtime may vary depending on the specific application and switching frequency.
• Can I use the IR2109SPBF with a different FET package?
  The IR2109SPBF is designed to work with FETs in a specific package (e.g., TO-220 or TO-247). While it may be possible to use it with FETs in a different package, the driver's output stage and layout may need to be modified to ensure proper operation and to prevent damage to the driver or FETs.
• How do I handle the undervoltage lockout (UVLO) feature?
  The IR2109SPBF has a built-in undervoltage lockout (UVLO) feature that disables the driver when the VCC supply voltage falls below a certain threshold (typically around 10.5V). To handle UVLO, ensure the VCC supply voltage is stable and within the recommended operating range, and consider adding a voltage supervisor or reset circuit to handle power-on reset and brown-out detection.