BOM for O+C (rev 2c)
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if your board is is labelled rev.2c (on top of the board, underneath the ‘ornament and crime’ label), that’s rev 2c. previous versions differ only slightly.
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the footprint for passives is 0805 throughout, except the five 10n caps (0603). using 0603 everywhere will work just as fine, of course.
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there’s five 3-pin pads for trimpots (input/output calibration): simply omit the trimpots; the calibration can be done entirely in software. use five jumper wires instead and, ideally, 0.1% resistors for the output stage (the “wiki” has more details): it’s cheaper and makes calibration easier.
SMD resistors (0805):
| value | # | part | note |
|---|---|---|---|
| 100R | 4x | e.g. mouser # 279-1623096-1 | 1% |
| 220R | 4x | e.g. mouser # 279-CPF0805B220RE1 | 1% |
| 510R | 2x | e.g. mouser # 603-RC0805JR-07510RL | 1-5% |
| 2k | 1x | e.g. mouser # 660-RK73H2ATTE2001F | 1% |
| 10k | 1x | e.g. mouser # 660-RK73H2ATTD1002F | 1-5% |
| 24k9 | 4x | e.g. mouser # 756-PCF0805R-24K9BT1 | 0.1% (‡) |
| 33k | 8x | e.g. mouser # 660-RK73H2ATTD3302F | 1% |
| 47k | 2x | e.g. mouser # 660-RK73H2ATTD4702F | 1% |
| 75k | 4x | e.g. mouser # 660-RK73H2ATTD7502F | 1% (silkscreen says 49k9: ignore) |
| 100k | 4x | e.g. mouser # 279-CPF0805B100KE | 0.1% |
| 100k | 8x | e.g. mouser # 660-RK73H2ATTD1003F | 1% (or simply get 12 x 0.1%) |
SMD caps (0603) (16V) :
| value | # | type | note |
|---|---|---|---|
| 10n | 5x | C0G/NP0 | e.g. mouser # 81-GRM1885C1H103JA1D |
SMD caps (0805) (25V or better):
| value | # | type | note |
|---|---|---|---|
| 18p-22p | 4x | C0G/NP0 (!) | e.g. mouser # 77-VJ0805A220GXAPBC |
| 100n | 12x | ceramic | e.g. mouser # 80-C0805C104K5R |
| 470n | 1x | ceramic | e.g. mouser # 77-VJ0805Y474JXJTBC |
| 1u | 2x | ceramic | e.g. mouser # 581-08055C105K4Z2A |
| 10u | 4x | ceramic (or tantal) | e.g. mouser # 81-GRM21BR6YA106KE3L |
ICs/semis:
| what | # | package | part |
|---|---|---|---|
| MCP6004 | 1x | (SOIC-14) | mouser # 579-MCP6004T-I/SL |
| OPA2172 | 2x | (SOIC-8) | mouser # 595-OPA2172IDR, and see note (†) below |
| DAC8565 | 1x | (TSSOP-16) | mouser # 595-DAC8565IAPW, 595-DAC8565ICPW |
| MMBT3904 (NPN) | 4x | (SOT-23) | mouser # 512-MMBT3904 |
| 1N5817 (diode) | 2x | (DO-41) | e.g. mouser # 621-1N5817 |
| LM4040 5v0 | 1x | (SOT-23) | e.g. mouser # 926-LM4040DIM350NOPB |
| ADP150-3v3 | 1x | (TSOT) | mouser # 584-ADP150AUJZ-3.3R7 |
| LM1117-50 | 1x | (SOT-223) | mouser # 511-LD1117S50 |
- (†) something fancier (= more suitable, $$) than TL072 should be used for the DAC output stage; using TL072 will be ok, but ideally, you want something with (very) low offset/noise/drift. for example: OPA2172, OPA2277
misc through-hole:
| what | # | note | part |
|---|---|---|---|
| 470nF cap | 1x | RM5 (16V) | e.g. mouser # 80-R82DC3470AA60K |
| 22uF cap | 2x | RM2.5 (35V or better) | e.g. mouser # 647-UPM1V220MDD1TD |
| inductor | 1x | 10uH | e.g. mouser # 542-78F100-RC |
| jacks | 12x | ‘thonkiconn’ (or kobiconn) | PJ301M-12 |
| encoders | 2x | 24 steps w/ switch | e.g. PEC11R-4215K-S0024 (†) |
| 2x5 pin header | 1x | 2.54mm (euro power connector) | e.g. mouser # 649-67996-410HLF |
| 1x7 (1x8) OLED socket | 1x | 2.54mm, low profile but not “machined” sockets with round holes for the pins - the square header pins on most OLED carrier boards will not fit sockets with round holes. Use the low-profile sockets indicated here, or equivalent -> | e.g mouser # 517-929870-01-08-RA |
| 1x14 socket | 2x | 2.54mm, socket for teensy 3.x | see note (††) |
| 1x14 pin header (to match) | 2x | 2.54mm, header for teensy 3.x | - |
| tact switches | 2x | multimecs 5E/5G | mouser #: 642-5GTH935 (†††) |
| + caps | 2x | multimecs 1SS09-15.0 or -16.0 | mouser #: 642-1SS09-15.0, or -16.0 |
| 3mm spacer | 1x | ∅ 3M, 10mm | - |
- (†) rotary encoder w/ switch: for instance: mouser # 652-PEC11R-4215F-S24 (15 mm, ‘D’ shaft); 652-PEC11R-4215K-S24 (15 mm shaft, knurled); 652-PEC11R-4220F-S24 (20 mm, ‘D’), 652-PEC11R-4220K-S24 (20 mm, knurled), etc).
- (††) best to use “machined pin” ones (also called “round” or “precision”): the pcb holes are small. Or these sockets from RS-Online are a good alternative and will accept standard square-pin 0.1 inch pitch headers.
- (†††) much cheaper is sos.
MCU/display:
| what | # | note | source |
|---|---|---|---|
| teensy 3.2 / 3.1 | 1x | cut the V_usb/power trace! | oshpark / mouser # 485-2756 |
| OLED | 1x | SH1106 or SSD1306 / 1.3” / 128x64 | see note (†) |
- (†) you can find these 1.3” displays on ebay or aliexpress for < 10$. as long as the description claims that they are
SH1106orSSD1306and the pinout is:GND - VCC - D0 - D1 - RST - DC - CS, they should work (orGND - VCC - CLK - MOSI - RES - DC - CS, which is the same). make sure you get the right size: 1.3” (not 0.96”)! - alternatively, the hardware/gerbers folder has .brd/.sch files for a/the OLED carrier board. in that case, you’d need to get the bare OLED. for example here (though there’s cheaper options for getting bare OLEDs).