Visible Light Sensor Design
Worked for 23 sec
Yes — this board has centroid/placement data. I generated the pick-and-place files:
- https://cdn2.flux.ai/flux-comment-files/files/commentFileId-1b50a6e9dca256259fecbf8845930290917f461bdbd7d66a07c61dfbc18a9966.csv?GoogleAccessId=autopilot-sa-d60c62b%40graviton-mvp.iam.gserviceaccount.com&Expires=4933661227&Signature=ZOVS2KEXRuA%2Fkm2XPdEXPcoszav2Kn1U78%2FRAHWTciGjnv%2FkJwVnl3A5mnpuvaK2j4pbuZWeQzZlTBoL5cu47QNt9zY1zwQgWHb%2FkLy68GDUcsrLDX28rkTDMgG7Fl%2FTb7H9bAfaY%2BIHxm%2FmS7EPm3BK%2FZzht1ryIhYGYoRrHRefriZwQWaxnmrbkFYKy0I7EgG9a3d2Jvi4XhZVpWDFvePeV%2Bthm65KP9SwG8KPBaWmhEmjQDci9KUPn1AG0br13560phTdx1yQHIQAYgmqr5KeUmJOX8ZzNLwE%2FXqy72Sfpj4q%2F06ZxeK7lsax4%2FoUuSuuJHjFfgoLwTXcLzdHhQ%3D%3D
- https://cdn2.flux.ai/flux-comment-files/files/commentFileId-2f01a6d0d230799b52fdf0491e0b733e55d4ec332995e548c859e4ff6ab2fe8d.csv?GoogleAccessId=autopilot-sa-d60c62b%40graviton-mvp.iam.gserviceaccount.com&Expires=4933661227&Signature=l1k5dvpiGxcssATKZiBoQysgiNAjrucaRpDgL5ho6k4KqGCOUUDO1PSajW%2BfBGOKlII3IRDdUnWIO2k0OSGoInwE3RagiOva1GU9HnrsrbGyn%2B2HEYotuEK4XpB9PMmUlqQuenzdMHN4A41fC2K4h4Ep31glFphIB7OWDY6S9ENDdbDvJI%2B%2FvotETtTO3H5E0KCiRNqbAhspO%2BbNeKZMv%2Fj8md5vx7yB6nMl%2FGtH0m18QfdAUXv4rpsxXK5tbcozhsRY1iKGcRIggjVTSxFASG6veE50BpnVnmGsAUCK0YhsreYX3VMfZjunAdFlCOIwNCndPiXjS1GLN6Ss1pEyyg%3D%3D
I also checked the key export blockers: no airwire, missing-footprint, invalid-layer, or overlapping-copper issues were reported.
do i need to provide both of those for a manufacturer?
Thought for 4 sec
Usually no — provide the centroid file format your manufacturer asks for.
- JLCPCB assembly: use the JLCPCB centroid/CPL CSV.
- OpenPNP / generic assembly house / desktop pick-and-place: use the OpenPNP CSV unless they request a specific format.
- If ordering bare PCBs only, you do not need either centroid file — just Gerbers/drill files.
- If ordering PCB assembly, you typically provide Gerbers + BOM + one pick-and-place/centroid file.
So for JLCPCB assembly: upload Gerbers, BOM, and the JLCPCB CPL/centroid CSV.
Export JLCPCB package
Check BOM MPNs
Bare PCB files
Export OpenPNP centroid
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Visible Light Sensor TIA Design Notes
Requirements
- Visible light/near-IR photodiode sensor.
- Photodiode operated in reverse bias for speed.
- Op amp amplifies photodiode output using a transimpedance topology.
- Output smoothing capacitor included.
- DIP switches allow feedback resistor changes during testing.
Selected Parts
- D1: SFH 203 photodiode, user-specified Mouser 720-SFH203.
- U1: OPA381AIDGKR transimpedance amplifier, user-specified Mouser 595-OPA381AIDGKR.
- SW1: TE Connectivity 1825360-3, 4-position SPST DIP switch.
- J1: 3-pin 2.54 mm header for +5V, GND, and analog output.
Circuit Topology
D1 cathode is connected to +5V and D1 anode is connected to the OPA381 inverting input summing node. U1 non-inverting input is tied to GND, so the summing node is held near ground while the photodiode is reverse-biased. Photocurrent is converted to voltage at U1 OUT through the selected feedback resistance.
The OPA381 output drives R5 and C4 as an output low-pass/smoothing filter before J1 pin 3. C1 is always connected from U1 OUT to the summing node as a feedback compensation capacitor.
Feedback / Gain Options
Switches enable feedback resistors in parallel:
Table
| Switch branch | Resistor | Nominal transimpedance |
|---|---|---|
| SW1 position 1 | R1 = 10kΩ | 10 mV/uA |
| SW1 position 2 | R2 = 100kΩ | 100 mV/uA |
| SW1 position 3 | R3 = 1MΩ | 1 V/uA |
| SW1 position 4 | R4 = 10MΩ | 10 V/uA |
If multiple switches are on, the effective feedback resistance is the parallel combination of the enabled resistors.
Filters and Stability
- C1 = 10pF feedback capacitor across the active feedback network for TIA stability and bandwidth control.
- R5 = 1kΩ and C4 = 100nF create an output smoothing pole of approximately 1.6 kHz.
- C2 = 100nF local bypass capacitor for U1.
- C3 = 10uF bulk capacitor on +5V.
Assumptions / Notes
- Supply is assumed to be +5V from J1 pin 1.
- J1 pinout: pin 1 = +5V, pin 2 = GND, pin 3 = ANALOG_OUT.
- The SFH 203 datasheet/library indicates reverse-bias operation is valid; +5V reverse bias is well below the listed reverse-voltage capability in distributor/library metadata.
- Very high gain settings, especially 10MΩ, may saturate in bright light and should be tested under expected illumination.
- Remaining review airwires are expected before PCB placement/routing; the schematic netlist is intentionally complete.
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