4 layers150 × 65 mm
2 layers40.6 × 38.1 mm
FFTSlice
Pyrograf/FFTSliceModule evaluating FFT with programmable gain control, filtering, and parallel/serial communication
- Size
- 40.6 × 38.1 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 61
- Nets
- 80
- Pads
- 214
- Tracks, vias
- 566, 103
- Pours
- 8
- Routed
- Yes
- KiCad
- KiCad 7 (file 20221018)
- Created
- 30 Mar 2023
- Updated
- 1 Aug 2023
Overview
FFTSlice is an open-source printed circuit board by Pyrograf, from the Pyrograf/FFTSlice repository on GitHub. It is a 2-layer board of 40.6 × 38.1 mm with 61 parts on 80 nets, routed with 566 tracks and 103 vias.
It is built around the SPX3819M5-L-3-3, BZM55C3V3 and PMEG2005EJ. Its parts include 21 capacitors, 9 resistors, 6 diodes, 5 ICs and 3 connectors. It belongs with the STM32 boards of this library.
Main components
3
SPX3819M5-L-3-3
SOT-23-5-40℃~+85℃@(Ta) 1 20V 3.3V 420mV@(100mA) 500mA 5uA 70dB@(1kHz) Fixed Over Current Protection、Over Temperature Protection、Enable Positive SOT-23-5 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSTECH PUBLICVoltage Regulators - Linear, Low Drop Out (LDO) Regulators
BZM55C3V3
Small Signal Zener DiodeVishay IntertechnologyUncategorised
PMEG2005EJ
-UncategorisedNexperia
README
README.mdFFTslice
Module to evaluate FFT. Communication with SPI. PGA for gain control. 2 selectable channels, additional DAC channel for selftest.
DAC samples generation
See notebook with all calculations.
Frequencies from 20 Hz to 20 kHz are splitted into 100 ranges in logspace to better fit sound perception.
3 variables affects output DAC frequency:
- constant TIM1 clock = 64 MHz,
- variable divider
- samples count
Divider can be freely changed, but samples count have to be generated in advance and stored in FLASH. There are 6 samples counts: 64, 128, 256, 512, 1024 and 2048. Higher samples counts fits better to generate low frequencies, lower samples counts are better fot higher frequencies.
100 parameters are calculated so that samples count and divider lowers time in which output voltage remain the same, and deviation from theoretical frequency is acceptable.
Resulting error remains below 1% as seen in the plot:
Matching of samples counts is more or less proportional:
Resulting frequencies are very close to theoretically calculated. In the plot sinewave with output buffer enabled without low pass filter:
Parts
61| Qty | Value | Footprint | References |
|---|---|---|---|
| 9 | TestPoint | TestPoint:TestPoint_Pad_D1.0mm | TP1, TP2, TP3, TP4, TP5, TP6, TP7, TP8, TP9 |
| 6 | 1uF | Capacitor_SMD:C_0603_1608Metric | C2, C13, C14, C17, C20, C21 |
| 5 | 100nF | Capacitor_SMD:C_0603_1608Metric | C4, C11, C12, C16, C18 |
| 4 | 100k | Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R6, R7, R8, R9 |
| 4 | 10nF | Capacitor_SMD:C_0603_1608Metric | C1, C10, C15, C19 |
| 4 | 4k7 | Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R1, R2, R3, R5 |
| 3 | 100nF | Capacitor_SMD:C_0402_1005Metric_Pad0.74x0.62mm_HandSolder | C7, C8, C9 |
| 3 | LED | LED_SMD:LED_0805_2012Metric_Pad1.15x1.40mm_HandSolder | D1, D2, D4 |
| 3 | ~ | Jumper:SolderJumper-2_P1.3mm_Bridged_RoundedPad1.0x1.5mm | JP1, JP2, JP3 |
| 2 | 10pF | Capacitor_SMD:C_0603_1608Metric | C3, C5 |
| 2 | 120R@100MHz | Inductor_SMD:L_0603_1608Metric_Pad1.05x0.95mm_HandSolder | FB1, FB2 |
| 2 | BZM55C3V3 | Diode_SMD:D_MicroMELF | D5, D6 |
| 2 | Conn_01x10 | Connector_PinSocket_2.54mm:PinSocket_1x10_P2.54mm_Vertical | J1, J3 |
| 2 | SPX3819M5-L-3-3 | Package_TO_SOT_SMD:SOT-23-5 | U3, U4 |
| 1 | 100uF | Capacitor_Tantalum_SMD:CP_EIA-6032-15_Kemet-U_Pad2.25x2.35mm_HandSolder | C6 |
| 1 | 16MHz 10pF | Crystal:Crystal_SMD_Abracon_ABM10-4Pin_2.5x2.0mm | Y1 |
| 1 | Conn_01x07 | Connector_PinSocket_2.54mm:PinSocket_1x07_P2.54mm_Vertical | J4 |
| 1 | LOGO | LOGO | G*** |
| 1 | MCP6S22-I_MS | Package_SO:SOP-8_3.9x4.9mm_P1.27mm | U5 |
| 1 | NA | Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R4 |
| 1 | PMEG2005EJ | Diode_SMD:D_SOD-323F | D3 |
| 1 | RESET | Button_Switch_SMD:SW_SPST_TL3342 | SW1 |
| 1 | STM32G081RBTx | Package_QFP:LQFP-64_10x10mm_P0.5mm | U1 |
| 1 | TS5A9411DCKR | TS5A9411DCKR_footprints:DCK0006A_N | U2 |
Questions
How big is the FFTSlice PCB?
It measures 40.6 × 38.1 mm and has 2 copper layers, 1.6 mm thick.
What parts does the FFTSlice use?
61 parts, built around the SPX3819M5-L-3-3, BZM55C3V3 and PMEG2005EJ. 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 FFTSlice KiCad files?
From the Pyrograf/FFTSlice repository on GitHub, at the commit this page was made from: the board is Board/fft_slice/fft_slice.kicad_pcb and its schematic Board/fft_slice/analog.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the FFTSlice design in my own project?
Its repository states no licence, so its author keeps all rights: ask Pyrograf before reusing the design.
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