600 mA synchronous buck in a 3 mm × 3 mm DFN
The Analog Devices LTC3409AEDD#PBF is a synchronous step-down (buck) regulator delivering 600 mA from a 1.6 V to 5.5 V input rail. The output is adjustable from 0.62 V up to 5.5 V, making it suitable for powering low-voltage cores, I/O banks, or post-regulation stages in battery-powered and portable equipment. Switching frequency is programmable between 1.7 MHz and 2.6 MHz, allowing the use of small inductors and ceramic capacitors while keeping switching losses manageable. The 8-DFN (3 mm × 3 mm) package with exposed pad helps spread heat into the PCB ground plane.
Input range and output flexibility
The 1.6 V minimum input lets this part run from a single Li-Ion cell deep into discharge, or from a 1.8 V logic rail. The 5.5 V maximum input covers 3.3 V and 5 V regulated buses with margin. Output voltage is set by an external resistor divider down to 0.62 V, so it can generate common rails like 1.2 V, 1.8 V, 2.5 V, 3.3 V, or 5 V — the buyer asking whether it can output 5 V or be used for 3.3 V output gets a yes on both, within the 600 mA limit.
Lifecycle and compliance
The LTC3409AEDD#PBF is listed as Active with ROHS3 compliance. For a BOM line that needs a small, efficient buck converter, this part carries no near-term supply risk and is suitable for new designs.