REF50xxAI LM4040
About the REF50xxAI LM4040 PCB
REF50xxAI LM4040 is an open source PCB design by Lusbert, published on GitHub under the Unlicense license. It is a 2-layer board measuring 60 × 30 mm, with 19 components from 15 distinct parts.
Other key parts include the REF5050AIDR 0.1% and LM4040C-2.5. By type, the board carries 5 test points, 5 capacitors, 5 resistors, 2 ICs, 1 transistor and 1 switch.
From the project
A voltage reference board providing 5.0V, 2.5V, and 1.25V using the REF5050AI and LM4040
This was the first PCB I made so it's obviously not perfect.
The LM4040 part was an after thought. It would've been better to divide the voltage from the REF5050 itself and have the switch be for that, but whatever.
Main components on the REF50xxAI LM4040
REF50xxAI LM4040 bill of materials (BOM)
19 components, 15 distinct parts.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | REF5050AIDR 0.1% | SOIC-8_5.3x6.2mm_P1.27mm | U1 |
| 1 | LM4040C-2.5 | TO-92_Wide | U2 |
| 1 | AO3401A | SOT-23 | Q1 |
| 1 | SW_DIP_x03 | SW_DIP_SPSTx03_Slide_9.78x9.8mm_W7.62mm_P2.54mm | SW1 |
| 1 | 5V | TestPoint_THTPad_D2.5mm_Drill1.2mm | TP1 |
| 1 | Ground | TestPoint_THTPad_D2.5mm_Drill1.2mm | TP2 |
| 1 | Temperature | TestPoint_THTPad_D2.5mm_Drill1.2mm | TP3 |
| 1 | 2.5V | TestPoint_THTPad_D2.5mm_Drill1.2mm | TP4 |
| 1 | 1.25V | TestPoint_THTPad_D2.5mm_Drill1.2mm | TP5 |
| 2 | 10µF Polymer | CP_Elec_5x5.7 | C1, C4 |
| 1 | 100nF Ceramic | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C2 |
| 2 | 1µF Ceramic | C_1206_3216Metric_Pad1.33x1.80mm_HandSolder | C3, C5 |
| 1 | 1k 0.1% | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R1 |
| 1 | 750 0.1% | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R2 |
| 3 | 10k 0.1% | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R3, R4, R5 |
REF50xxAI LM4040 design files
The KiCad project lives in the Lusbert/REF50xxAI_LM4040_PCB repository on GitHub; these links point at the commit this page was built from.
- LayoutPCB/ref5050_vref.kicad_pcb
- SchematicPCB/ref5050_vref.kicad_sch
REF50xxAI LM4040: common questions
How big is the REF50xxAI LM4040 PCB?
The REF50xxAI LM4040 measures 60 × 30 mm, has 2 copper layers and is 1.2 mm thick.
How many components are on the REF50xxAI LM4040?
19 components, from 15 distinct parts. The full bill of materials is listed on this page.
Where can I download the REF50xxAI LM4040 design files?
From the Lusbert/REF50xxAI_LM4040_PCB repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.
Can I use the REF50xxAI LM4040 design in my own project?
Yes, under the terms of its Unlicense license, which Lusbert chose for the repository.