400 mA adjustable buck in a 1.6×1.6 mm TMLF package
The Microchip MIC23031-AYMT-TR is a 400 mA, 4 MHz step-down (buck) switching regulator from the HyperLight Load® series. The synchronous rectifier keeps efficiency up without an external Schottky diode.
4 MHz switching — small inductor, fast transient
At 4 MHz the part stays above the AM band, so it won't couple into sensitive RF front-ends in wireless modules. The high switching rate also means the inductor value drops to the 1 µH range and the output capacitor can be as low as 4.7 µF ceramic — a real space saver on a 1.6×1.6 mm TMLF footprint. The trade-off is slightly higher switching losses at light loads, but the HyperLight Load architecture keeps quiescent current low enough for battery-powered standby.
125°C junction temperature — good for automotive and industrial
The exposed pad on the 6-UFDFN / 6-TMLF package needs a solid thermal via stitch to the ground plane to keep the junction below the 125°C ceiling at full 400 mA load in a 85°C ambient.