4 layers238.4 × 144.7 mm
2 layers120 × 120 mm
A1 Main Board
D-LCR/A1_Main-BoardLCR Meter Analogue Main Board
- Size
- 120 × 120 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 217
- Nets
- 181
- Pads
- 710
- Tracks, vias
- 1,828, 346
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 2 May 2026
- Updated
- 24 May 2026
Overview
A1 Main Board is an open-source printed circuit board by D-LCR, from the D-LCR/A1_Main-Board repository on GitHub. It is a 2-layer board of 120 × 120 mm with 217 parts on 181 nets, routed with 1,828 tracks and 346 vias.
It is built around the ULN2003, AGQ200A12 and BAV99, with the BAV199, TIP41C and TIP42C among its other parts. Its parts include 96 resistors, 53 capacitors, 18 ICs, 15 diodes and 9 connectors. It belongs with the STM32 boards of this library.
Main components
6
ULN2003
SOP-161.1V@250uA,100mA 25pF 2V 30V 500mA 50uA 50uA Seven channels SOP-16 Darlington Transistor Arrays ROHSBLDarlington Transistor Arrays
AGQ200A12
SMD,10.6x7.2mm-40℃~+85℃ 1.028kΩ 100mΩ 110V@DC、125V@AC 12V 140mW 2A 300mA@125VAC、1A@30VDC、2A@30VDC 4ms 4ms AgPd + Gold Plated Two groups of conversions: 2C(Double-pole double-throw conversion) SMD,10.6x7.2mm Signal Relays ROHSPanasonicSignal Relays
BAV99
SOT-231 Pair Series Connection 1.25V@150mA 100V 215mA 250mW 4A 4ns 500nA@80V SOT-23 Switching Diodes ROHSNexperiaSwitching DiodesBAV199
SOT-231 Pair Series Connection 1.25V@150mA 160mA 4A 5nA@75V 85V SOT-23 Diodes - General Purpose ROHSNexperiaDiodes - General Purpose
TIP41C
TO-220-3L-55℃~+150℃ 1 NPN 1.5V 100V 15 2W 3MHz 400uA 5V 6A NPN TO-220-3L Bipolar (BJT) ROHSJiangsu Changjing Electronics Technology (CJ)Bipolar (BJT)TIP42C
TO-220-3L-55℃~+150℃ 1 PNP 1.5V 100V 2W 30 3MHz 400uA 5V 6A PNP TO-220-3L Bipolar (BJT) ROHSJiangsu Changjing Electronics Technology (CJ)Bipolar (BJT)
README
README.mdD-LCR_A1_Main-Board
LCR Meter Analogue Main Board
Parts
217| Qty | Value | Footprint | References |
|---|---|---|---|
| 24 | 100n | Capacitor_SMD:C_0805_2012Metric | C1, C3, C4, C10, C11, C12, C13, C19, C20, C23, C24, C25, C33, C37, C39, C40 +8 |
| 15 | 10k | Resistor_SMD:R_0805_2012Metric | R6, R7, R8, R9, R13, R15, R16, R22, R33, R34, R54, R75, R77, R78, R88 |
| 11 | 100k | Resistor_SMD:R_0805_2012Metric | R3, R4, R18, R52, R53, R59, R60, R61, R64, R79, R90 |
| 8 | 10 | Resistor_SMD:R_2512_6332Metric | R25, R26, R29, R30, R50, R51, R55, R56 |
| 8 | 100 | Resistor_SMD:R_0805_2012Metric | R27, R28, R31, R32, R57, R58, R62, R63 |
| 7 | AGQ200A12 | AGQ:RELAY_AGQ_A_PAN | K1, K2, K3, K4, K5, K6, K7 |
| 6 | 10µ | Capacitor_SMD:C_0805_2012Metric | C14, C15, C16, C17, C21, C22 |
| 6 | 2k | Resistor_SMD:R_0805_2012Metric | R20, R21, R35, R36, R48, R49 |
| 6 | OPA2197xD | Package_SO:SOIC-8_3.9x4.9mm_P1.27mm | U3, U4, U5, U6, U8, U13 |
| 5 | 1k | Resistor_SMD:R_0805_2012Metric | R1, R2, R65, R84, R95 |
| 5 | BAV99 | Package_TO_SOT_SMD:SOT-23 | D4, D5, D6, D9, D15 |
| 5 | DG201 | Package_SO:SOIC-16_3.9x9.9mm_P1.27mm | U2, U9, U12, U14, U17 |
| 4 | 22u | Capacitor_SMD:C_1210_3225Metric | C50, C51, C52, C53 |
| 4 | 39k | Resistor_SMD:R_0805_2012Metric | R68, R76, R86, R89 |
| 4 | Conn_Coaxial | Connector_Coaxial:BNC_Amphenol_B6252HB-NPP3G-50_Horizontal | J2, J3, J4, J5 |
| 4 | MountingHole | MountingHole:MountingHole_3.2mm_M3 | H1, H2, H3, H4 |
| 4 | TBD | Diode_SMD:D_SMA | D11, D12, D13, D14 |
| 3 | 1.1k | Resistor_SMD:R_0805_2012Metric | R19, R80, R91 |
| 3 | 180k | Resistor_SMD:R_0805_2012Metric | R24, R39, R47 |
| 3 | 20k | Resistor_SMD:R_0805_2012Metric | R23, R38, R46 |
| 3 | 220 | Resistor_SMD:R_0805_2012Metric | R10, R11, R96 |
| 3 | 50 | Resistor_SMD:R_0805_2012Metric | R5, R40, R41 |
| 3 | 56p | Capacitor_SMD:C_0805_2012Metric | C31, C38, C46 |
| 3 | BAV199 | Package_TO_SOT_SMD:SOT-23 | D1, D2, D3 |
| 3 | Conn_01x02_Pin | Connector_Molex:Molex_KK-254_AE-6410-02A_1x02_P2.54mm_Vertical | J1, J7, J8 |
| 3 | OPA2376xxD | Package_SO:SOIC-8_3.9x4.9mm_P1.27mm | U10, U15, U18 |
| 3 | TIP41C | Package_TO_SOT_THT:TO-220-3_Vertical | Q2, Q4, Q6 |
| 3 | TIP42C | Package_TO_SOT_THT:TO-220-3_Vertical | Q3, Q5, Q7 |
| 2 | 1.5k | Resistor_SMD:R_0805_2012Metric | R70, R87 |
| 2 | 10M | Resistor_SMD:R_0805_2012Metric | R37, R69 |
| 2 | 12k | Resistor_SMD:R_0805_2012Metric | R67, R85 |
| 2 | 2.2p | Capacitor_SMD:C_0805_2012Metric | C36, C45 |
| 2 | 2.7M | Resistor_SMD:R_0805_2012Metric | R45, R74 |
| 2 | 2.7k | Resistor_SMD:R_0805_2012Metric | R42, R73 |
| 2 | 22p | Capacitor_SMD:C_0805_2012Metric | C34, C43 |
| 2 | 27k | Resistor_SMD:R_0805_2012Metric | R43, R72 |
| 2 | 3.9k | Resistor_SMD:R_0805_2012Metric | R81, R92 |
| 2 | 300k | Resistor_SMD:R_0805_2012Metric | R44, R71 |
| 2 | 330p | Capacitor_SMD:C_0805_2012Metric | C27, C29 |
| 2 | 5.6n | Capacitor_SMD:C_0805_2012Metric | C18, C32 |
| 2 | 7p | Capacitor_SMD:C_0805_2012Metric | C35, C44 |
| 2 | 9k | Resistor_SMD:R_0805_2012Metric | R83, R94 |
| 2 | DFLS240LX | Diode_SMD:D_PowerDI-123 | D7, D8 |
| 2 | INA828D | Package_SO:SOIC-8_3.9x4.9mm_P1.27mm | U11, U16 |
| 1 | 1.47k | Resistor_SMD:R_0805_2012Metric | R17 |
| 1 | 1.6n | Capacitor_SMD:C_0805_2012Metric | C28 |
| 1 | 11k | Resistor_SMD:R_0805_2012Metric | R82 |
| 1 | 160p | Capacitor_SMD:C_0805_2012Metric | C30 |
| 1 | 16n | Capacitor_SMD:C_0805_2012Metric | C26 |
| 1 | 180p | Capacitor_SMD:C_0805_2012Metric | C7 |
| 1 | 1M | Resistor_SMD:R_0805_2012Metric | R66 |
| 1 | 1u | Capacitor_SMD:C_0805_2012Metric | C2 |
| 1 | 2.4k | Resistor_SMD:R_0805_2012Metric | R14 |
| 1 | 2N7002 | Package_TO_SOT_SMD:SOT-23 | Q1 |
| 1 | 3.3V | TestPoint:TestPoint_Pad_2.0x2.0mm | TP1 |
| 1 | 30k | Resistor_SMD:R_0805_2012Metric | R12 |
| 1 | 4.7u | Capacitor_SMD:C_0805_2012Metric | C6 |
| 1 | 50.4k | Resistor_SMD:R_0805_2012Metric | R93 |
| 1 | Conn_01x03_Pin | Connector_Molex:Molex_KK-254_AE-6410-03A_1x03_P2.54mm_Vertical | J6 |
| 1 | Conn_01x05_Pin | Connector_Molex:Molex_KK-254_AE-6410-05A_1x05_P2.54mm_Vertical | J9 |
| 1 | ECS-2520MV-xxx-xx | Oscillator:Oscillator_SMD_ECS_2520MV-xxx-xx-4Pin_2.5x2.0mm | Y1 |
| 1 | FerriteBead | Inductor_SMD:L_0805_2012Metric | FB1 |
| 1 | GND | TestPoint:TestPoint_Pad_2.0x2.0mm | TP3 |
| 1 | LED | LED_SMD:LED_0805_2012Metric | D10 |
| 1 | RST | TestPoint:TestPoint_Pad_2.0x2.0mm | TP5 |
| 1 | STM32G491CCUx | Package_DFN_QFN:QFN-48-1EP_7x7mm_P0.5mm_EP5.6x5.6mm | U1 |
| 1 | SWCLK | TestPoint:TestPoint_Pad_2.0x2.0mm | TP2 |
| 1 | SWDIO | TestPoint:TestPoint_Pad_2.0x2.0mm | TP4 |
| 1 | SolderJumper_3_Bridged12 | Jumper:SolderJumper-3_P1.3mm_Bridged12_RoundedPad1.0x1.5mm | JP2 |
| 1 | ULN2003 | Package_SO:SOIC-16_3.9x9.9mm_P1.27mm | U7 |
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Questions
How big is the A1 Main Board PCB?
It measures 120 × 120 mm and has 2 copper layers, 1.6 mm thick.
What parts does the A1 Main Board use?
217 parts, built around the ULN2003, AGQ200A12, BAV99 and BAV199. 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 A1 Main Board KiCad files?
From the D-LCR/A1_Main-Board repository on GitHub, at the commit this page was made from: the board is Circuit/Main Board.kicad_pcb and its schematic Circuit/Bridge.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the A1 Main Board design in my own project?
Its repository states no licence, so its author keeps all rights: ask D-LCR before reusing the design.