High-side driver with 80 V bootstrap ceiling
The LTC4440EMS8E#PBF is a single-channel high-side gate driver from Analog Devices, designed to drive an N-channel MOSFET in a bootstrap configuration. The 80 V maximum high-side voltage (bootstrap) sets the ceiling for the switched node voltage, making it suitable for 48 V bus converters, telecom power supplies, and industrial DC-DC stages where the top FET sees the full rail. Peak output current is 2.4 A for both source and sink, with typical rise and fall times of 10 ns and 7 ns respectively into a 1 nF load. This combination charges the MOSFET gate capacitance quickly, minimising switching transition losses in medium-frequency converters operating in the 100 kHz to 1 MHz range.
Supply rail and logic interface
The driver operates from an 8 V to 15 V supply rail, which powers both the internal circuitry and the bootstrap charging path. The non-inverting input type means the output follows the input polarity — a logic high at the IN pin turns the external MOSFET on. This simplifies control loop design in voltage-mode and current-mode topologies where the PWM signal directly commands the power switch.
Package thermal and board integration
The 8-MSOP-EP (exposed pad) package, 3.00 mm width, requires a thermal via array under the pad to conduct heat to the PCB ground plane. The exposed paddle is electrically connected to GND, so the via pattern must match the datasheet recommended footprint to avoid solder voids during reflow. Surface-mount assembly with a moisture sensitivity level (MSL) typical for this package class — the part should be baked per J-STD-033 if the floor life has been exceeded.
The part ships in tube packaging, which is standard for prototype and low-volume kitting.