Infineon – IRS25751L: High Voltage Start-Up IC Simplifies Design

The IRS25751 is a 480V high voltage start-up IC ideal for supplying initial supply starting current from a high voltage bus. The IRS25751 supplies a constant current during start-up and then consumes ultra-low stand-by (off) current. Additional features include programmability of the upper turn-off threshold, an ENN input, and over-temperature protection. IR’s proprietary HVIC technology provides robust operation from high input voltage levels with simple yet flexible features.


  • Up to 480V voltage capability
  • Programmable upper threshold level
  • Over-temperature shutdown
  • Internal 20.8V clamp on VOUT pin
  • Integrated ESD protection on all pins
  • 24-lead 4 x 4mm QFN package
  • 1k MSRP: $2.45 US
  • Constant output current (4.5mA)
  • Fixed lower threshold (4.2V)
  • 2.5μA off current
  • Excellent latch immunity on all inputs and outputs
  • 5-pin SOT-23 package