Half-bridge driver that ran its production run
The Infineon IR2151SPBF is a self-oscillating half-bridge gate driver designed for driving IGBTs and N-Channel MOSFETs in a synchronous configuration. It integrates a 600V bootstrap supply for the high-side gate, an RC input circuit that sets the oscillator frequency, and two output channels with 125mA source / 250mA sink peak current capability. The 80ns rise and 40ns fall times (typical) keep switching losses manageable in the 20-100 kHz range typical of half-bridge converters, electronic ballasts, and switch-mode power supplies. The 10V to 20V supply range gives headroom for driving standard MOSFET threshold voltages without an external regulator.
The 600V high-side voltage max (bootstrap) is the hard ceiling for the DC bus in your half-bridge topology. If you're running a 400V DC bus from a rectified 230VAC line, you have 200V of margin — comfortable. If you're pushing toward a 550V bus from a three-phase rectifier, the margin gets thin and you need to watch switching transients that could exceed the rating. The 150°C TJ max is the absolute limit — at continuous high ambient you'll need to derate the output current per the datasheet's thermal impedance curves. The 125mA source / 250mA sink peak output is asymmetric: the stronger sink pulls the gate down faster than the source pulls it up. That's intentional for half-bridge shoot-through prevention — the low-side turn-off is quicker than the high-side turn-on. For a power MOSFET with 30-50 nC total gate charge, expect gate rise/fall in the 80-150 ns range depending on the external gate resistor.
The closest functional replacement path is to evaluate the IR2153 series (self-oscillating half-bridge) or the IRS2153 family, which share the same basic topology but have different pinouts and dead-time characteristics. A pin-to-pin drop-in replacement is not guaranteed without checking the datasheet's recommended replacement note. For a board in production that already uses the IR2151SPBF, the realistic sourcing path is through independent distribution. The 8-SOIC package is common, so the physical part is findable in surplus channels, but quantities over a few thousand may require splitting across multiple date-code lots.
Package and mounting — the 8-SOIC footprint
The surface-mount footprint is standard SOIC-8 with 1.27 mm pitch — no exotic land pattern needed.