2 layers57 × 57.3 mm
2 layers60 × 50 mm
Discrete PLL
adasbl/Discrete-PLL-pcbDiscrete PLL (Phase-Locked Loop) design implemented in KiCad
- Size
- 60 × 50 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 59
- Nets
- 34
- Pads
- 159
- Tracks, vias
- 429, 65
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 8.0 (file 20240108)
- Created
- 2 Apr 2026
- Updated
- 5 Apr 2026
Overview
Discrete PLL is an open-source printed circuit board by adasbl, from the adasbl/Discrete-PLL-pcb repository on GitHub. It is a 2-layer board of 60 × 50 mm with 59 parts on 34 nets, routed with 429 tracks and 65 vias.
It is built around the CD4030BE, CD4148WTP and BC846, with the BC857 among its other parts. Its parts include 16 resistors, 15 connectors, 12 capacitors, 5 transistors and 4 diodes.
Main components
4
CD4030BE
PDIP-14-55℃~+125℃ 1.5V~4V 100ns@15V,50pF 1uA 3.4mA 3.4mA 3.5V~11V 3V~18V 4 4000B Series XOR Gate PDIP-14 Logic Gates ROHSTexas InstrumentsLogic Gates
CD4148WTP
0603Switching DiodesYONGYUTAI
BC846
SOT-23-65℃~+150℃ 1 NPN 100mA 110 15nA 250mW 400mV 65V 6V 770MHz NPN SOT-23 Bipolar (BJT) ROHSNexperiaBipolar (BJT)BC857
SOT-231 PNP 100MHz 100mA 15nA 200mW 45V 5V 650mV 800 PNP SOT-23 Bipolar (BJT) ROHSSTMicroelectronicsBipolar (BJT)
README
README.mdDiscrete-PLL-pcb
Electronics project featuring a Discrete Phase-Locked Loop (PLL).
pcb photos and renders:
pcb layout:
circuit diagram:
Project Scope
- Design: Analog-digital schematic and custom PCB layout in KiCad.
- Hardware: Discrete architecture utilizing CD4030B XOR gates and TL074 op-amps.
- Assembly: Hand-soldered board featuring BC846/857 transistor pairs.
Repository Structure
/KiCad-files– Schematic and PCB source files./gerbers– Manufacturing data (Gerber and Drill files)./images– PCB renders, schematic exports, and project photos.schematic.pdf– Full circuit diagram.
Parts
59| Qty | Value | Footprint | References |
|---|---|---|---|
| 13 | 10k | Resistor_SMD:R_0603_1608Metric | R1, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16 |
| 6 | PIN2 | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | J2, J5, J6, J8, J9, J17 |
| 6 | PIN4 | Connector_PinHeader_2.54mm:PinHeader_1x04_P2.54mm_Vertical | J11, J14, J16, J18, J19, J20 |
| 5 | 10nF | Capacitor_SMD:C_0603_1608Metric | C1, C3, C10, C11, C12 |
| 4 | 100nF | Capacitor_SMD:C_0603_1608Metric | C6, C7, C8, C9 |
| 4 | CD4148WT | Diode_SMD:D_0603_1608Metric_Pad1.05x0.95mm_HandSolder | D1, D2, D3, D4 |
| 4 | MountingHole | MountingHole:MountingHole_3.2mm_M3_DIN965 | H1, H2, H3, H4 |
| 3 | 1nF | Capacitor_SMD:C_0603_1608Metric | C2, C4, C5 |
| 3 | BC846 | Package_TO_SOT_SMD:SOT-23 | Q2, Q3, Q4 |
| 3 | PIN3 | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | J1, J3, J15 |
| 2 | 33k | Resistor_SMD:R_0603_1608Metric | R2, R4 |
| 2 | BC857 | Package_TO_SOT_SMD:SOT-23 | Q1, Q5 |
| 1 | 10R | Resistor_SMD:R_0603_1608Metric | R3 |
| 1 | 47k | library2xd:Potentiometer_CAP_CA14_VA12,5_Vertical | RV1 |
| 1 | CD4030B | Package_SO:SOIC-14_3.9x8.7mm_P1.27mm | U2 |
| 1 | TL074 | Package_SO:SOIC-14_3.9x8.7mm_P1.27mm | U1 |
Questions
How big is the Discrete PLL PCB?
It measures 60 × 50 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Discrete PLL use?
59 parts, built around the CD4030BE, CD4148WTP, BC846 and BC857. 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 Discrete PLL KiCad files?
From the adasbl/Discrete-PLL-pcb repository on GitHub, at the commit this page was made from: the board is KiCad-files/Discrete-PLL.kicad_pcb and its schematic KiCad-files/Discrete-PLL.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Discrete PLL design in my own project?
Its repository states no licence, so its author keeps all rights: ask adasbl before reusing the design.
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