What this buck regulator does
The MAX1623EAP+T is a step-down (buck) switching regulator delivering up to 3 A from a 4.5 V to 5.5 V input rail. It uses synchronous rectification. Output is adjustable with presets at 1.1 V, 2.525 V, and 3.33 V, programmable up to 3.8 V. Switching frequency runs up to 350 kHz. The part comes in a 20-pin SSOP package rated for -40°C to 85°C.
Output current and voltage — what they mean for your rail
The 3 A output rating is the continuous current the regulator can source at the programmed output voltage. The adjustable output range from 1.1 V to 3.8 V covers common logic voltages. Fixed presets are 1.1 V, 2.525 V, and 3.33 V.
Switching frequency and synchronous rectification
Switching at up to 350 kHz allows smaller inductor and output capacitor. The synchronous rectifier replaces the freewheeling diode with a low-Rds(on) MOSFET, improving efficiency at higher output currents.
Package and mounting
The 20-SSOP package (5.30 mm body width, 0.209" pitch) is a surface-mount footprint. It is not a power-pad package, so the thermal path is through the leads and the PCB copper. For 3 A continuous output, the board needs a decent copper pour on the output and ground planes to keep the junction temperature within the -40°C to 85°C operating range. The part is available in Tape & Reel for pick-and-place assembly or Cut Tape for prototyping runs.
Lifecycle and compliance
The MAX1623EAP+T is listed as Active in production — no end-of-life notice, no last-time-buy window to worry about. It is ROHS3 compliant, so it meets the current European and global restrictions on hazardous substances.