Half-bridge driver for a synchronous buck rail
The ADP3412JR is a dual N-channel MOSFET driver from Analog Devices, configured as a half-bridge with synchronous drive for the high-side and low-side FETs. It is the glue between a PWM controller and the power stage in a synchronous buck converter, typically found on voltage regulator modules for processor cores, telecom line cards, and base station power supplies.
20 ns edges — dead-time and switching loss budget
The 20 ns typical rise and fall time sets the transition window where both FETs are off. A controller with adaptive dead-time can use this edge rate to minimise body-diode conduction loss without risking shoot-through. The 20 ns spec is fast enough for switching frequencies up to about 500 kHz before the dead-time eats into the duty-cycle range. Supply range of 4.15 V to 7.5 V means this driver runs from a 5 V or 7 V rail, not the 12 V bus common on older half-bridge drivers. The gate drive voltage is therefore limited to the supply rail minus the bootstrap diode drop — about 4.5 V to 7 V at the high-side gate. That is enough to fully enhance a logic-level N-channel MOSFET with a Vgs(th) below 2.5 V. The bootstrap pin is rated to 30 V maximum, which caps the input voltage of the buck converter at about 24 V nominal with margin. A 48 V input bus would exceed the bootstrap rating and damage the driver.
The 125°C upper limit is typical for a junction-temperature-rated driver; the actual case temperature will be lower depending on the thermal impedance of the 8-SOIC footprint.
The 8-SOIC package is a common, low-cost footprint that rework techs can replace with hot air — no preheater needed.