2 layers23.9 × 13.7 mm
Elec
eigenlucy/micromppt
800mV-5.5Vin <5W high efficiency MPPT battery charger with autonomous perturb and observe set point adjustment
23 parts13MIT
2 layers
Voltage window
eigenlucy/micromppt13800mV-5.5Vin <5W high efficiency MPPT battery charger with autonomous perturb and observe set point adjustment
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 9
- Nets
- 7
- Pads
- 20
- Tracks, vias
- 28, 2
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 28 Nov 2024
- Updated
- 6 Sep 2025
Overview
Voltage window is an open-source printed circuit board by eigenlucy, from the eigenlucy/micromppt repository on GitHub, published under the MIT licence. It is a 2-layer board with 9 parts on 7 nets, routed with 28 tracks and 2 vias.
Its parts include 6 resistors and 3 ICs. It belongs with the power boards of this library.
README
README.mdmicromppt
SPV1040 Based 5W MPPT Boost Charger With Autonomous Perturb-and-Observe Set Point Adjustment
Tiny, versatile, high efficiency solar charging, designed with Meshtastic clients in mind
This release has been configured for single cell lipo charging, and includes an XB3306 lithium battery protection circuit. I have tested this converter with avariety of cell chemistries, as well as supercapacitors, and I will release a more minimal SPV1040 package in the upcoming week with configuration guidelines to for a more general purpose multichemistry solar charging module. See the project page on my website for more configuration guidelines, panel recommendations, and ordering info (WIP).
Built with atopile and KICAD 9. See my atopile usage guide for help installing and using atopile
TO DO:
- Split the project into a base micromppt module and a number of input and output projection modules
- Solve Vout divider with assertions, add cutoff and BPC for other chemistries
Parts
9| Qty | Value | Footprint | References |
|---|---|---|---|
| 6 | 10kΩ ±1% 62.5mW | atopile:R0402-56259e | R1, R2, R3, R4, R5, R6 |
| 2 | atopile:SOT-23-3_L2.9-W1.3-P1.90-LS2.4-BR-688f29 | U1, U2 | |
| 1 | atopile:LED0402-R-RD-049f90 | U3 |
Questions
What parts does the Voltage window use?
9 parts. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Voltage window KiCad files?
From the eigenlucy/micromppt repository on GitHub, at the commit this page was made from: the board is elec/layout/voltage-window/voltage-window.kicad_pcb and its schematic elec/layout/default/default.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Voltage window design in my own project?
Its repository publishes it under the MIT licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
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