Active production — parametric fit for the BOM line
The MIC2179YSM is an active-production step-down buck regulator from Microchip Technology, rated for 1.5 A continuous output with an adjustable output voltage from a 1.245 V reference up to the 16.5 V input maximum. The -40°C to 125°C junction temperature range qualifies it for engine-bay or outdoor enclosure deployment where ambient heat pushes the die above 85°C.
No synchronous rectifier — external diode selection
The MIC2179YSM does not integrate a synchronous rectifier — the low-side freewheeling diode must be added externally. A 2 A Schottky with a Vf below 0.5 V at 1.5 A keeps the efficiency above 85% at full load; the diode's reverse voltage rating should exceed the 16.5 V input maximum with margin.
Sourcing posture and compliance
ROHS3 compliant — the part is free of the ten restricted substances under EU RoHS, including the four phthalates added in 2015/863. No UL, CSA, or IEC certification is stated in the listing.