4 layers85.6 × 54 mm
4 layers200 × 100 mm
MinUS
kelu124/minus3Minimal ultrasound platform
- Size
- 200 × 100 mm
- Copper layers
- 4
- Thickness
- 1.6 mm
- Parts
- 222
- Nets
- 201
- Pads
- 793
- Tracks, vias
- 2,488, 336
- Pours
- 4
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 17 Sep 2026
- Updated
- 7 Nov 2026
Overview
MinUS is an open-source printed circuit board by kelu124, from the kelu124/minus repository on GitHub. It is a 4-layer board of 200 × 100 mm with 222 parts on 201 nets, routed with 2,488 tracks and 336 vias.
It is built around the RP2354A, AD8432ACPZ-R7 and MD1213K6-G, with the AD8338ACPZ-RL, MD0100N8-G and TC4427AEUA713 among its other parts. Its parts include 77 capacitors, 57 resistors, 21 ICs, 6 diodes and 5 connectors. It belongs with the RP2350 and PIC boards of this library.
Main components
12
RP2354A
QFN-60(7x7)150MHz 32 Bit ARM Cortex-M33 Built-in+External Power-on reset (POR)、Undervoltage detection (BOR/LVD/LVR/LVI)、Watchdog reset、Built-in general-purpose timer、Integrated LDO、Calendar function、True random number generator (TRNG)、Hardware ECC check、Independent watchdog (IWDG) QFN-60(7x7) Microcontrollers (MCU/MPU/SOC) ROHSRaspberry PiMicrocontrollers (MCU/MPU/SOC)
AD8432ACPZ-R7
QFN-24-EP(4x4)-40℃~+85℃ 1mV 2 24mA 295V/us 300uV/℃ 4.5V~5.5V 5.5V 77mA 850pV/√Hz@1MHz Enable/shutdown function QFN-24-EP(4x4) Low Noise Amplifiers (LNA) - RF ROHSAnalog DevicesLow Noise Amplifiers (LNA) - RF
MD1213K6-G
QFN-12-EP(4x4)-40℃~+85℃ 0V~300mV 2 2A 2A 3V~5V 4.5V~13V 550uA 6ns 6ns 7ns 7ns MOSFET QFN-12-EP(4x4) Gate Drivers ROHSMicrochip TechnologyGate Drivers
AD8338ACPZ-RL
LFCSP-16(3x3)-40℃~+85℃ 1 18MHz 3V~5V 3mA 50V/us Differential VGA LFCSP-16(3x3) Programmable / Variable Gain Amplifiers (PGA/VGA) ROHSAnalog DevicesSpecial Purpose Amplifiers
MD0100N8-G
SOT-89-3-40℃~+125℃ SOT-89-3 Interface - Specialized ROHSMicrochip TechnologyInterface - Specialized
TC4427AEUA713
MSOP-8-40℃~+85℃ 1.5A 1.5A 100uA 2 25ns 25ns 4.5V~18V MOSFET MSOP-8 Gate Drivers ROHSMicrochip TechnologyGate Drivers
MCP4131-104E/SN
SOIC-8-40℃~+125℃ 1 1.8V~5.5V 100kHz 100kΩ 129 2.5uA 50ppm/℃ 75Ω Linear Power-on reset RAM SPI ±20% SOIC-8 Digital Potentiometers ROHSMicrochip TechnologyDigital PotentiometersMCP4531-103E/MS
MSOP-8-40℃~+125℃ 1 1.8V~5.5V 10kΩ 129 1LSB 1MHz 2.5uA 50ppm/℃ 75Ω I2C Linear Power-on reset RAM ±20% MSOP-8 Digital Potentiometers ROHSMicrochip TechnologyDigital PotentiometersTC6320TG-G
SOIC-8-55℃~+150℃ 1 N-Channel + 1 P-Channel 110pF 1V 200V 23pF 2A 8Ω@10V SOIC-8 MOSFETs ROHSMicrochip TechnologyMOSFETs
AP2112K-3.3TRG1
SOT-25-5-40℃~+85℃@(Ta) 1 250mV@(600mA) 3.3V 50uVrms 55uA 600mA 65dB@(1kHz) 6V Fixed Over Current Protection、Thermal Shutdown、Enable control Positive SOT-25-5 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSDiodes IncorporatedVoltage Regulators - Linear, Low Drop Out (LDO) Regulators
BAT54
SOT-23200mA 2uA@25V 30V 800mV@100mA Independent SOT-23 Schottky Diodes ROHSFOSANSchottky Diodes
WS2812
SMD5050-4P1.57mm 1000mcd 110mcd 120us 2kHz 3.7V~5.3V 300ns 320mcd 451nm 523nm 5mm 5mm 623nm 800Kbit/s Built-in power-on reset circuit、Built-in power-on reset circuit Top-mount SMD5050-4P RGB LEDs(Built-in IC) ROHSWorldsemiRGB LEDs(Built-In IC)
README
README.mdminus
A minimal, single-channel, low-cost, open-source ultrasound pulse-echo platform — built as a conference-workshop badge.
minus drives one piezo transducer with a high-voltage pulse, amplifies and digitizes
the returning echo, and streams the raw data to a host. It is designed to be cheap,
small, simple, and hackable — a badge attendees can use in an ultrasound-conference
workshop (e.g. muscle-contraction monitoring, A-/M-mode) and then extend and
experiment with (coded excitation, on-device DSP, add-on boards).
⚠️ Status: early design. This repository currently holds the requirements, a survey of comparable systems, a component trade study, and reference designs — not yet a finished board. Non-clinical, for research / education / NDT only; not a medical device.
What it is (at a glance)
- MCU: Raspberry Pi RP2350 — precise pulse timing + fast ADC capture via PIO.
- Signal: 3–4 MHz piezo (provided with the kit), raw RF A-mode + M-mode.
- Front end: unipolar HV pulser (bipolar option) → T/R switch → VGA/TGC → external high-speed ADC. Reuses proven blocks from the author's open boards.
- Badge: on-board USB-C (host + power), RGB LED + small OLED for standalone display, Raspberry-Pi 40-pin extension header, transducer via SMA / header / uFL, friendly silkscreen + test points, OSHWA certification planned.
- Open: open hardware + firmware + host software; designed for JLCPCB fabrication.
Repository map
| Path | What's there |
|---|---|
requirements.md | The design requirements (MoSCoW), with open decisions. |
analysis.md | Architecture analysis — integrated vs external-ADC routes; pulser and gain options. |
options.md + options_prices.csv | Component trade study (pulser / gain / ADC) with LCSC-referenced pricing. |
systems/ | Survey of ~19 comparable ultrasound systems (datasheets, literature, by-IC index). |
design/ | Reference design files (un0rick, lit3rick, pic0rick, Open Echo, BioGAP shield). |
pdfs/ | Source papers and component datasheets. |
docs/claude/ | Working notes: session logs, decision memory, TODO/DONE, changelog. |
Lineage & credits
minus builds on the open single-channel ultrasound work of Luc Jonveaux (kelu124) —
echomods/Murgen,
un0rick,
lit3rick, and
pic0rick — reusing their proven building blocks
to reduce risk. See systems/ for the broader field survey.
License
Intended to be released as open hardware + open software (OSHWA certification planned), following the licensing of the boards above.
Parts
222| Qty | Value | Footprint | References |
|---|---|---|---|
| 44 | 100nF | EasyEDA:C0402 | C1, C2, C3, C15, C16, C20, C21, C23, C25, C27, C29, C33, C34, C36, C100, C101 +28 |
| 21 | CONUFL001-SMD-T | EasyEDA:IPEX-SMD_3P-L2.6-W2.6-LS3.0 | RF1, RF10, RF11, RF12, RF13, RF14, RF15, RF16, RF17, RF18, RF19, RF20, RF21, RF22, RF23, RF24 +5 |
| 14 | 10KΩ | EasyEDA:R0402 | R5, R30, R31, R32, R33, R40, R41, R42, R43, R44, R48, R50, R52, R54 |
| 8 | 0Ω | EasyEDA:R0402 | R17, R18, R21, R22, R24, R25, R56, R57 |
| 7 | 1uF | EasyEDA:C0402 | C17, C18, C32, C58, C62, C64, C66 |
| 7 | Jumper_3_Open | PCM_SparkFun-Jumper:Jumper_3_NO | JP2, JP3, JP4, JP6, JP7, JP8, JP9 |
| 6 | 1nF | EasyEDA:C0402 | C19, C22, C24, C26, C28, C30 |
| 5 | PZ254V-11-01P | EasyEDA:HDR-TH_1P-P2.54-V-M | H3, H4, H5, H6, H7 |
| 4 | 4.7uF | EasyEDA:C0402 | C9, C10, C11, C14 |
| 4 | 50Ω | EasyEDA:R0402 | R28, R29, R36, R37 |
| 4 | MountingHole_Pad | MountingHole:MountingHole_2.2mm_M2_Pad | H8, H9, H10, H11 |
| 3 | 10nF | Capacitor_SMD:C_0402_1005Metric | C60, C61, C67 |
| 3 | 10uF | EasyEDA:C0603 | C35, C49, C53 |
| 3 | 1KΩ | EasyEDA:R0402 | R47, R49, R51 |
| 3 | 1kΩ | EasyEDA:R0402 | R4, R6, R7 |
| 3 | BAV99 | Package_TO_SOT_SMD:SOT-23 | D4, D5, D7 |
| 3 | Conn_01x03_Pin | Connector_PinSocket_2.54mm:PinSocket_1x03_P2.54mm_Vertical | J4, J5, J6 |
| 3 | TS-1088-AR02016 | EasyEDA:SW-SMD_L3.9-W3.0-P4.45 | SW1, SW2, SW3 |
| 2 | 100R | Resistor_SMD:R_0402_1005Metric | R68, R69 |
| 2 | 100Ω | EasyEDA:R0402 | R45, R46 |
| 2 | 10Ω | EasyEDA:R0402 | R38, R39 |
| 2 | 120Ohm 3 A | Inductor_SMD:L_1206_3216Metric | FB5, FB6 |
| 2 | 132414 | EasyEDA:SMA-SMD_132414 | RF4, RF9 |
| 2 | 15pF | EasyEDA:C0402 | C12, C13 |
| 2 | 2.2uF | EasyEDA:C0603 | C47, C48 |
| 2 | 20Ω | EasyEDA:R0402 | R13, R14 |
| 2 | 22Ω | EasyEDA:R0402 | R1, R2 |
| 2 | 330nF | EasyEDA:C0402 | C43, C45 |
| 2 | 47Ω | EasyEDA:R0402 | R8, R10 |
| 2 | 56pF | EasyEDA:C0402 | C93, C94 |
| 2 | 5K1 | Resistor_SMD:R_0402_1005Metric | R71, R72 |
| 2 | Jumper_2_Bridged | PCM_4ms_SolderJumper:JUMPER_SMD_1x2 | JP1, JP5 |
| 2 | MCP4131-104E/SN | EasyEDA:SOIC-8_L4.9-W3.9-P1.27-LS6.0-BL | U12, U14 |
| 2 | MCP4531-103E/MS | EasyEDA:MSOP-8_L3.0-W3.0-P0.65-LS5.0-BL | U11, U18 |
| 2 | MD1213K6-G | EasyEDA:QFN-12_L4.0-W4.0-P0.80-BL-EP1.7 | IC1, IC3 |
| 2 | NetTie_2 | NetTie:NetTie-2_SMD_Pad0.5mm | NT1, NT2 |
| 2 | TC6320TG-G | EasyEDA:SOIC-8_L4.9-W3.9-P1.27-LS6.0-BL | IC2, IC4 |
| 1 | 0Ω | EasyEDA:R1206 | R11 |
| 1 | 100KΩ | EasyEDA:R0402 | R12 |
| 1 | 12MHz | EasyEDA:OSC-SMD_4P-L3.2-W2.5-BL_SIT8008BI | U16 |
| 1 | 15Ω | EasyEDA:R0402 | R19 |
| 1 | 240Ω | EasyEDA:R0402 | R34 |
| 1 | 27Ω | EasyEDA:R0402 | R35 |
| 1 | 2N7002_C916396 | EasyEDA:SOT-23-3_L2.9-W1.3-P1.90-LS2.4-BR | Q4 |
| 1 | 3.3uH | EasyEDA:IND-SMD_L2.0-W1.6_AOTA-B201610S3R3-101-T | L1 |
| 1 | 330Ω | EasyEDA:R0402 | R55 |
| 1 | 33Ω | EasyEDA:R0402 | R3 |
| 1 | 39.2Ω | EasyEDA:R0402 | R26 |
| 1 | 4.7kΩ | EasyEDA:R0603 | R53 |
| 1 | 442Ω | EasyEDA:R0402 | R9 |
| 1 | 470nF | EasyEDA:C0603 | C31 |
| 1 | 47pF | EasyEDA:C0402 | C40 |
| 1 | 750Ω | EasyEDA:R0402 | R27 |
| 1 | AD8338ACPZ-RL | EasyEDA:LFCSP-16_L3.0-W3.0-P0.50-BL-EP1.6 | U10 |
| 1 | AD8432ACPZ-R7 | EasyEDA:LFCSP-24_L4.0-W4.0-P0.50-BL-EP | U6 |
| 1 | AP2112K-3.3TRG1 | EasyEDA:SOT-25-5_L2.9-W1.6-P0.95-LS2.8-BL | U15 |
| 1 | BAT54S_C916425 | EasyEDA:SOT-23-3_L2.9-W1.3-P1.90-LS2.4-BR | D1 |
| 1 | BAT54_C22466368 | EasyEDA:SOT-23-3_L2.9-W1.4-P1.90-LS2.5-BR | U3 |
| 1 | Conn_ARM_SWD_TagConnect_TC2030-NL | Connector:Tag-Connect_TC2030-IDC-NL_2x03_P1.27mm_Vertical | J1 |
| 1 | HS91L02W2C01 | EasyEDA:OLED-TH_L38.0-W12.0_HS91L02W2C01 | OLED1 |
| 1 | IRLML2244TRPBF | EasyEDA:SOT-23-3_L2.9-W1.6-P1.90-LS2.8-BR | Q2 |
| 1 | IRLML6244TRPBF | EasyEDA:SOT-23-3_L2.9-W1.3-P1.90-LS2.4-BR | Q1 |
| 1 | KT-0603R | EasyEDA:LED-SMD_L1.6-W0.8-R-RD | LED2 |
| 1 | LMH6629MFX/NOPB | EasyEDA:SOT-23-5_L2.9-W1.6-P0.95-LS2.8-BR | U7 |
| 1 | MCP4728A0T-E/UN | EasyEDA:MSOP-10_L3.0-W3.0-P0.50-LS5.0-BL | U13 |
| 1 | MD0100N8-G | Package_TO_SOT_SMD:SOT-89-3 | U17 |
| 1 | OPA847IDR | EasyEDA:SOIC-8_L4.9-W3.9-P1.27-LS6.0-TL | U8 |
| 1 | PIC32AK1216GC41048-I_PT | EasyEDA:QFP50P900X900X120-48N | U2 |
| 1 | PZ254V-11-02P | EasyEDA:HDR-TH_2P-P2.54-V-M | H1 |
| 1 | PZ254V-12-18P | EasyEDA:HDR-TH_18P-P2.54-V-M-R2-C9-S2.54 | H2 |
| 1 | RP2354A | EasyEDA:QFN-60_L7.0-W7.0-P0.40-TL-EP3.4 | U1 |
| 1 | SK6812_C5378720 | EasyEDA:LED-SMD_4P-L5.4-W5.0_SK6812 | LED1 |
| 1 | TC4427AEUA713 | EasyEDA:MSOP8_MC_MCH-M | U4 |
| 1 | TYPE-C-31-M-12 | EasyEDA:USB-C_SMD-TYPE-C-31-M-12_1 | USBC1 |
| 1 | WS2812 | EasyEDA:LED-SMD_4P-L5.0-W5.0-TL-A | U5 |
| 1 | X9555WV-2X20-6TV01 | EasyEDA:IDC-TH_40P-P2.54_X9555WV-2X20-6TV01 | CN1 |
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Questions
How big is the MinUS PCB?
It measures 200 × 100 mm and has 4 copper layers, 1.6 mm thick.
What parts does the MinUS use?
222 parts, built around the RP2354A, AD8432ACPZ-R7, MD1213K6-G and AD8338ACPZ-RL. 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 MinUS KiCad files?
From the kelu124/minus repository on GitHub, at the commit this page was made from: the board is hardware/minUS_10102026/minUS.kicad_pcb and its schematic design/open-echo/TUSS4470_shield.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the MinUS design in my own project?
Its repository states no licence, so its author keeps all rights: ask kelu124 before reusing the design.