Half-bridge driver with integrated bootstrap — the 600 V high-side ceiling
The Infineon IR2153S is a half-bridge gate driver designed for driving two N-Channel MOSFETs in a synchronous half-bridge configuration. Its key differentiator is the 600 V maximum high-side bootstrap voltage, which sets the DC bus ceiling for offline flyback, LLC resonant, and two-switch forward converters. The RC input circuit allows the oscillator frequency and dead-time to be set with a single resistor and capacitor on the RT/CT pin — a common topology in self-oscillating half-bridge controllers. Supply range is 10 V to 15.6 V, matching standard 12 V and 15 V bias rails from auxiliary windings.
80 ns rise, 45 ns fall — switching-speed budget for dead-time
Typical rise time of 80 ns and fall time of 45 ns define the minimum dead-time window needed to avoid shoot-through. In a 100 kHz LLC converter, the 35 ns asymmetry between rise and fall means the dead-time must be set to the slower edge, not averaged. The 8-SOIC package keeps the gate-drive loop tight — the output traces to the MOSFET gates should be under 10 mm to keep the switching node clean. Two drivers in a single package, each rated for the full 10 V to 15.6 V supply range. The bootstrap diode is integrated, so the high-side driver's floating supply is generated from the low-side supply and the switching node — no external bootstrap diode needed.
Infineon no longer manufactures this part in volume. The closest functional replacement is the IR2153 (non-S suffix) in a DIP-8 package, but that changes the board footprint and the thermal profile. For a drop-in SMD replacement, the IR21531S or IR2153D series parts share the same 8-SOIC footprint and bootstrap architecture — confirm the dead-time resistor range matches your oscillator design.
The 8-SOIC package on a 2-layer board with a copper pour under the driver keeps the junction below 110°C at 25°C ambient with a 500 pF gate load at 100 kHz.