Buck-boost regulator for automotive power rails
The MAX20040BATPA/VY+ from Maxim Integrated is a single-output buck-boost switching regulator rated for automotive environments. It accepts a 2 V to 36 V input range and delivers a programmable output up to 15 V at 1.2 A, switching at 2.2 MHz. The buck-boost topology keeps the output regulated whether the input sits below, at, or above the output voltage — a requirement for automotive battery rails that swing during cold-crank, start-stop, and load-dump transients. The part is AEC-Q100 qualified and operates from -40°C to 125°C, placing it in the under-hood or engine-bay tier, not just cabin electronics. The package includes an exposed pad for thermal dissipation and wettable flanks on the QFN pads, which lets automated optical inspection (AOI) verify solder-joint quality on the production line.
2.2 MHz switching — small inductor, tight layout
At 2.2 MHz, the switching frequency pushes the inductor and output capacitor values down, shrinking the total power-stage footprint for space-constrained ECU layouts. The trade-off is that the switching edges couple into the PCB more easily — plan a solid ground plane under the IC and keep the switching node loop short. The synchronous rectifier (integrated) improves efficiency and removes the external Schottky diode, saving one component and one placement step.
Output programming — resistor divider sets the voltage
The output voltage is programmable via an external resistor divider, with a range up to 15 V. The fixed-programmable designation means the internal reference is fixed, but the feedback pin accepts the divider ratio to set the output.
Lifecycle and sourcing
The MAX20040BATPA/VY+ carries an Active lifecycle status and is ROHS3 compliant. It is not in a last-time-buy or phase-out window. For production programs that need a qualified second source, no pin-compatible alternate is listed on the official cross-reference — the part is sole-sourced to Maxim's automotive line.