• Inductor-less Buck Regulators are here with PN Labs' NanoBuck

    10/14/2025 at 20:24 • 0 comments

    Overview

    If you’ve ever found yourself digging through your parts bin trying to find just the right voltage regulator for a given module, the NanoBuck is made to simplify that pain. Instead of stocking four different fixed regulators, this tiny adjustable step-down module gives you 3.3 V, 5 V, 9 V, or 12 V options via simple solder jumpers. It accepts a broad input voltage range (4.5-36 V, absolute max 40 V) and can deliver up to 2-2.5 A continuous (depending on thermal conditions).

    Why I built it

    In my own projects I frequently needed regulators in multiple voltages. Switching from 12 V to 5 V then to 3.3 V meant either carrying multiple linear regulators (inefficient) or many buck modules (space, cost, inventory). I wanted a compact, efficient, jumper-configurable module that can be reused across projects. That led me to use TI's inductor-less buck regulator, the TPSM33625RDNR.

    Key Features & Specs

    FeatureSpec / Behavior
    Input voltage4.5 V - 36 V (40 V absolute max)
    Output selections3.3 V, 5 V, 9 V, 12 V (via solder jumpers)
    Max continuous current2.0-2.5 A (depends on input voltage, thermal conditions, and heatsinking)
    Efficiency80 % to 95 % (with heatsink)
    ProtectionOver-current shutoff, thermal shutdown with auto-retry
    Control pinsEnable pin, Power-Good pin
    Soft start~4 ms
    Package / mountingSMT module with castellated edges; breadboard headers included (flat or right-angle)
    HeatsinkA small heatsink (with thermal tape) is included to help with higher current

    Because the inductor is inside (integrated), you eliminate a bulky external coil and the associated layout headaches. The internal shielding also helps reduce radiated EMI. The controller uses Dual Random Spread Spectrum (DRSS) to further smooth out switching noise peaks.

    You can learn more about the NanoBuck, download it's datasheet and CAD files, and purchase it directly from my website, pnlabs.ca