Boost regulator with a 750 mA switch in a 3x3 TDFN
The Maxim MAX8569AETT+T is a step-up (boost) switching regulator with an adjustable output voltage, built around a 750 mA internal switch. It accepts an input from 1.5 V up to 5.5 V, making it suitable for single-cell alkaline, NiMH, or Li-ion battery-powered designs. The output can be set from a 2 V minimum up to 5.5 V via external feedback resistors. Synchronous rectification is integrated, so no external Schottky diode is needed for the boost path — that saves a component and a bit of board area. The part comes in a 6-pin TDFN package with an exposed pad (3x3 mm footprint) rated for surface-mount assembly.
Package and thermal handling
The 6-TDFN (3x3 mm) package has an exposed pad that must be soldered to a PCB copper plane for adequate thermal dissipation. Without a proper via stitch under the pad, the junction temperature will climb quickly at high output. The operating temperature range of -40°C to 85°C covers industrial and outdoor enclosures, but the thermal pad is the limiting factor for high-load scenarios — budget a few thermal vias and a solid ground pour on the bottom layer.
Lifecycle and compliance
The MAX8569AETT+T is listed as Active in production with ROHS3 compliance.