This project is a reference design for a VL53L4CD-based sensor circuit. It incorporates the use of a Texas Instruments LP5907MFX-2.8/NOPB to regulate the supply voltage. #referenceDesign #VL53L4CD #project #template #LIDAR #sensor #distance #referenceDesign #industrialsensing #stm #template #reference-design #polygon

The Texas Instruments MSP430FR604x and MSP430FR603x family comprises highly integrated ultrasonic sensing and measurement system-on-chips (SoCs) designed specifically for water and heat metering applications. The featured components, including MSP430FR6047, MSP430FR60471, MSP430FR6045, MSP430FR6037, MSP430FR60371, and MSP430FR6035, deliver best-in-class ultrasonic water flow measurement with ultra-low power consumption. These microcontrollers excel with an active mode current consumption of approximately 120 µA/MHz and a standby mode power draw as low as 450 nA with a real-time clock (RTC) enabled. Key functionalities include a high-precision differential time-of-flight (dTOF) accuracy of less than 25 ps, integrated analog front-end, programmable pulse generation (PPG), and an analog comparator. They also interface directly with standard ultrasonic sensors up to 2.5 MHz and feature up to 256KB FRAM, robust RAM options, and integrated LCD drivers for up to 264 segments. The embedded low-energy accelerator (LEA) enhances digital signal processing capabilities, making these components ideal for battery-powered metering solutions. Peripherals include multiple enhanced serial communication interfaces, high-performance ADCs, DMA controllers, and a suite of timers and encryption modules. These features combine to offer a powerful solution for high-accuracy, low-cost, and ultra-low-power metering applications.

This project is a reference design based on the BQ25895, a single cell Li-Ion battery charger. It manages the power between an external power source (VIN), a Li-Ion battery (BAT), and a system power rail (SYS). Key features include power-path management, battery thermistor monitoring, and charge status indication. #project #BQ25895 #ReferenceDesign #charger #BatteryManagemen #referenceDesign #bms #texas-instruments #template #reference-design #polygon

This is a reference design of TPS56339 DC-DC Converter IC with input voltage 4.5-24V and output 5V and 3A #dcdc #ti #power #3A #5V #referenceDesign #powermanagement #texas-instruments #template #reference-design

This project appears to be a power supply circuit using the TPS54331 step-down (Buck) converter from Texas Instruments. The target output voltage is 3.3V. It also features electromagnetic interference (EMI) mitigation components such as an inductor, capacitors and a diode. An LED is included for indication purposes. #Buck #TPS54331 #project

This project is a reference design utilizing Texas Instruments' PGA300ARHHR, a precision analog and digital IC, for signal processing. The circuit also includes a Diodes Incorporated's FZT603QTA Transistor, passive components like resistors and capacitors, and connectors from JST Sales America Inc. #project #referenceDesign #industrialsensing #texas-instruments #template #reference-design

The TUSB8041 by Texas Instruments is a highly integrated four-port USB 3.0 hub controller designed to facilitate high-speed data transfers and power management in computer systems, docking stations, monitors, and set-top boxes. This component offers simultaneous SuperSpeed USB (5 Gbps), high-speed (480 Mbps), full-speed (12 Mbps), and low-speed (1.5 Mbps) data connections, ensuring backward compatibility with USB 2.0 and USB 1.x devices. Key features include multi-transaction translation with four transaction translators, asynchronous endpoint buffers for improved data management, and comprehensive battery charging support compliant with various standards including CDP, DCP, and Chinese Telecommunications Industry Standard YD/T 1591-2009. Flexible power management options are available, catering to both per-port and ganged power control configurations, alongside over-current protection mechanisms. The device also supports custom configurations via OTP ROM, serial EEPROM, or I2C/SMBus interfaces, enabling customization for vendor IDs, product IDs, port specifics, and string descriptors. Ease of integration is further enhanced with the ability for on-board and in-system OTP/EEPROM programming via the USB 2.0 upstream port, and the device requires no special drivers, operating seamlessly with any OS that supports USB. Packaged in a compact 64-pin QFN format, the TUSB8041 is offered in both commercial (0℃ to 70℃) and industrial temperature (-40℃ to 85℃) ranges, ensuring robust performance across diverse environmental conditions. With a single clock input requirement and comprehensive system resource support, the TUSB8041 is ideal for developers aiming to implement high-performance and reliable USB hubs in their designs.

This ADM3054BRWZ-RL7-based reference design is a CAN bus transceiver circuit, providing reliable data communication over the CAN network. The design features a range of capacitors and resistors to ensure signal integrity, and a NUP2105L for voltage protection. It's ideal for applications requiring reliable data communication in an automotive or industrial environment. #referenceDesign #project #CANbus #interface #transceiverCircuit #ADM3054 #ADM3054BRWZ-RL7 #referenceDesign #canbus #texas-instruments #template #reference-design #reference-design

This ADM3054BRWZ-RL7-based reference design is a CAN bus transceiver circuit, providing reliable data communication over the CAN network. The design features a range of capacitors and resistors to ensure signal integrity, and a NUP2105L for voltage protection. It's ideal for applications requiring reliable data communication in an automotive or industrial environment. #referenceDesign #project #CANbus #interface #transceiverCircuit #ADM3054 #ADM3054BRWZ-RL7 #referenceDesign #canbus #texas-instruments #template #reference-design #reference-design

This project is a reference design based on the BQ25606, a single cell Li-Ion battery charger. It manages the power between an external power source (VIN), a Li-Ion battery (BAT), and a system power rail (SYS). Key features include power-path management, battery thermistor monitoring, and charge status indication. #project #BQ25606 #ReferenceDesign #charger #BatteryManagement #referenceDesign #bms #texas-instruments #template #reference-design #polygon

The TCA9555 is a 16-bit I/O expander for the 1.65-V to 5.5-V Vcc operation designed by Texas Instruments. It serves to enhance the general-purpose remote I/O expansion for most microcontroller families via the I2C interface. Key features of the TCA9555 include low standby-current consumption, 5-V I/O ports, 400-Khz fast I2C bus, and ESD protection. It finds applications across personal computers, servers, routers, industrial automation equipment, and products with GPIO-limited processors.

The Texas Instruments TPA3140D2 is a high-efficiency, Class-D audio power amplifier designed for driving bridged-tied stereo speakers with outputs up to 10 W per channel into 6 Ω or 8 Ω loads. With advanced EMI suppression technology, including spread spectrum control and a 1SPW modulation scheme, the TPA3140D2 ensures robust performance while minimizing electromagnetic interference. Operating within a wide supply voltage range from 4.5 V to 14.4 V, this amplifier eliminates the need for heat sinks due to its up to 90% efficient Class-D operation. Integrated SpeakerGuard™ protection features such as automatic gain limit (AGL), adjustable power limiter, and DC protection enhance speaker safety and audio quality. Additionally, the TPA3140D2 includes comprehensive protection against pin-to-pin, pin-to-ground, and pin-to-power short circuits, as well as thermal protection with auto recovery. The device offers four selectable fixed gain settings and supports both single-ended and differential analog inputs, making it suitable for a variety of consumer audio applications including televisions, wireless speakers, mini speakers, and USB speakers. The TPA3140D2 is available in a 28-pin HTSSOP package, ensuring ease of integration into compact designs.

This project is a reference design for a VL53L0CXV0DH-based sensor circuit. It incorporates the use of a Texas Instruments LP5907MFX-2.8/NOPB to regulate the supply voltage. #referenceDesign #VL53L0 #Module #template #LIDAR #sensor #distance #reusable #module #industrialsensing #stm #sublayout

DIP794W45P254L959H508Q8 https://snapeda.com/shop?store=Arrow+Asia&id=106817 PDIP-8 Texas 2-Channel, 1MHz, industry standard, 32V op amp 8-PDIP 0 to 70 LM358N/NOPB Texas Instruments https://snapeda.com/shop?store=DigiKey&id=106817 https://snapeda.com/shop?store=Mouser&id=106817 None Good Aliases: undefined

TPS62130 Is a Texas instrument Buck Converter IC in the TPS family of power devices. This converter has a maximum input range of...

This project is a reference design for a VL53L0CXV0DH-based sensor circuit. It incorporates the use of a Texas Instruments LP5907MFX-2.8/NOPB to regulate the supply voltage. #referenceDesign #VL53L0 #Module #template #LIDAR #sensor #distance #reusable #module #industrialsensing #stm #sublayout

DIP825W47P254L1917H533Q14 PDIP-14 Texas Instruments LM324N 4-Channel industry standard operational amplifier 14-PDIP 0 to 70 https://pricing.snapeda.com/search/part/LM324N/?ref=eda Texas Instruments None In Stock Aliases: undefined

This is an isolated CAN bus breakout board that uses the Texas Instruments chipset ISO1050 along with an isolated DC/DC converter.

Texas Instruments presents the CD4051B, CD4052B, and CD4053B series, a family of CMOS single 8-Channel, differential 4-Channel, and triple 2-Channel analog multiplexers or demultiplexers with logic-level conversion. Engineered for precise, reliable control of analog and digital signals, these components are characterized by their wide range of signal handling (3 V to 20 V for digital and up to 20 VP-P for analog signals), low ON resistance (125 Ω typical over 15 VP-P signal input range for VDD - VEE = 18 V), high OFF resistance (+100 pA typical channel leakage at VDD - VEE = 18 V), and minimal quiescent power dissipation (0.2 μW typical at VDD - Vss = VDD - VEE = 10 V). They come equipped with on-chip binary address decoding for easy integration and minimized system logic complexity. Available in a variety of package types, including CDIP, PDIP, SOIC, SOP, and TSSOP, these multiplexers/demultiplexers support a broad spectrum of analog to digital and digital to analog conversion applications, signal gating, factory automation, and other uses where reliable signal handling is crucial. With parametric ratings at 5 V, 10 V, and 15 V, and an operational temperature range of -55°C to 125°C, these components are also 100% tested for quiescent current at 20 V, assuring dependable performance across diverse environmental conditions.

## PROJECT OVERVIEW Design a compact, battery-powered, IoT-connected plant monitoring PCB sensor node. The board combines WiFi/BLE connectivity, multi-sensor I2C acquisition, LiPo battery management with USB-C charging, and partially weatherproof design for outdoor/planter use. The physical form factor is a FORK (forcina) shape: a wider rectangular head section (~32×30mm) housing all the electronics, and two narrow prongs (~10×45mm each, 8mm gap between them) extending downward to form the capacitive soil moisture electrodes. Reference: the shape resembles a plant stake that is pushed into soil. I trust Flux AI's routing and placement judgment. Please apply your full expertise. The guidance below defines constraints — treat them as requirements, not suggestions. --- ## BOARD SPECIFICATIONS - Layers: 2 (Top + Bottom copper) - Dimensions: Head 32×30mm + two prongs 10×45mm (total board ~32×75mm) - PCB thickness: 1.6mm FR4 - Surface finish: ENIG (Electroless Nickel Immersion Gold) — MANDATORY Reason: the soil prong traces must be gold-plated for corrosion resistance - Min trace width: 0.15mm signal, 0.5mm power - Min clearance: 0.15mm - Soldermask: GREEN on both sides Exception: NO soldermask on the interdigital soil electrode traces on the prongs (the copper must be fully exposed to contact the soil) - Via: min hole 0.3mm, pad 0.6mm - 4× M2.5 mounting holes (2.7mm drill, 5mm annular copper ring) at corners of head section - Conformal coating keep-out zones: SHT40-AD1F-R2 (U8), VEML7700 (U2), soil electrode traces on prongs, USB-C connector J1 --- ## COMPLETE BILL OF MATERIALS ### Active ICs **U1 — ESP32-C3-MINI-1** (Espressif, LCSC C2838502) - Main microcontroller: RISC-V 32-bit 160MHz, 4MB flash, 400KB RAM - WiFi 802.11b/g/n 2.4GHz + BLE 5.0 - Package: SMD module 13.2×16.6×2.4mm, castellated edges - Operating voltage: 3.0–3.6V from VCC rail - I2C: SDA=GPIO8, SCL=GPIO9 - USB: D+=IO19, D-=IO18 - Status outputs: CHG_STATUS=IO2, PG_STATUS=IO3, LOAD_EN=IO4 - CRITICAL placement: antenna area (rightmost ~3mm of module) must hang over board edge OR have copper keepout zone (no copper top or bottom under antenna area). This is mandatory for RF performance. - Add 100nF + 10µF decoupling on 3V3 pin, placed within 1mm of pin **U2 — VEML7700-TT** (Vishay, LCSC C78606) - Ambient light sensor, 0.0036–120,000 lux, I2C address 0x10 - Package: ODFN-6, 2.0×2.0×0.5mm - Operating voltage: 2.5–3.6V - Current: 90µA active, 0.2µA power-down - CRITICAL placement: position at TOP EDGE of head section, centered horizontally. The sensor photodiode window (top of package) must face upward toward the case lid. A transparent PMMA optical window (Ø10mm) in the case will be positioned directly above this IC. Leave 0mm clearance to board edge on that side if possible. The VEML7700 has ±45° field of view, so alignment does not need to be perfect, but centering under the window opening is preferred. - Add 100nF decoupling on VDD, placed within 1mm **U3 — SHT40-AD1B** (Sensirion, LCSC C1550099) — INTERNAL sensor - Temperature + relative humidity sensor, I2C address 0x44 - Package: DFN-4, 1.5×1.5×0.5mm — extremely small, requires careful pad design - Operating voltage: 1.8–3.6V - Current: 3.2µA per measurement (1ms active), 0.1µA sleep - PURPOSE: measures temperature and humidity INSIDE the case (ambient reference) - CRITICAL placement: position in CENTER of head section PCB, far from all heat sources. Minimum 8mm distance from BQ24090 (U6) and ME6211 (LDO1). The SHT40 chip surface IS the sensor — the hygroscopic polymer capacitor is on the top face of the IC. It must NOT be covered by conformal coating. However, for the internal sensor (U3), it can be in a slightly ventilated cavity inside the case to measure internal temperature drift compensation. - Add 100nF decoupling on VDD within 1mm **U8 — SHT40-AD1F-R2** (Sensirion, LCSC C5155469) — EXTERNAL sensor - Same electrical specs as U3 (SHT40 family), I2C address 0x44 - Package: DFN-4 with integrated PTFE filter cap for dust/water protection The filter cap allows vapor to reach the sensor while blocking liquid water - PURPOSE: measures EXTERNAL ambient temperature and humidity (outside the case) - CRITICAL placement: position on the SIDE or BOTTOM EDGE of head section. This sensor must be accessible from outside the case through a ventilated chamber (labyrinth vent structure in case design). It must NOT be covered by conformal coating. The sensor's filter cap must face the vent opening direction. Minimum 10mm distance from BQ24090 and LDO thermal zone. - Connected via TCA9548A channel 1 (see below) — NOT directly on main I2C bus **U4 — FDC1004DGST** (Texas Instruments, LCSC C266239) - 4-channel capacitance-to-digital converter, I2C address 0x50 - Package: WSON-8, 2.0×2.0×0.8mm - Operating voltage: 3.3V - Current: 750µA active, 300nA shutdown - PURPOSE: reads capacitance of interdigital PCB traces immersed in soil. The IC itself is NOT the soil sensor — it measures the capacitance of external electrodes. CIN1 and CIN2 connect to the interdigital copper traces on the prong section. - CRITICAL placement: position at BOTTOM of head section, closest to prong entry point. This minimizes trace length to CIN1/CIN2, reducing parasitic capacitance pickup. Keep CIN1 and CIN2 traces short, wide (0.3mm+), shielded by GND guard rings on both sides of each trace. Route CIN1/CIN2 on the SAME layer (Bottom preferred) as the interdigital electrodes to avoid via parasitic capacitance. - SHLD1 and SHLD2 pins connect to GND (guard shield) - Add 100nF decoupling on VDD within 1mm **U5 — TCA9548A** (Texas Instruments, LCSC C130026) — NEW COMPONENT vs previous schema - 8-channel I2C multiplexer, I2C address 0x70 - Package: SOIC-24 or TSSOP-24, select smallest available footprint - Operating voltage: 1.65–5.5V - PURPOSE: MANDATORY to resolve I2C address conflict between U3 and U8, both of which have fixed address 0x44. Without this IC the two SHT40 sensors will collide on the bus and produce corrupt readings. Channel 0: connects to U3 (SHT40 internal) Channel 1: connects to U8 (SHT40 external) Main I2C bus (from ESP32): connects to TCA9548A upstream SDA/SCL - Add 100nF decoupling on VCC within 1mm - Reset pin (active low): connect to VCC via 10kΩ (always enabled) OR connect to a GPIO for software reset capability **U6 — BQ24090DGQT** (Texas Instruments, LCSC C179663) - Single-cell LiPo/Li-ion battery charger, input 4.5–6.5V, charge voltage 4.2V - Package: DSBGA-9 (wafer-level), extremely small ~1.6×1.6mm - CRITICAL THERMAL: this IC dissipates up to 0.5W during charging. Place a copper thermal pad area ≥1cm² on BOTH layers under the IC. Add minimum 4 thermal vias (0.3mm hole, 0.6mm pad) under thermal exposed pad. Keep this IC at MAXIMUM distance from both SHT40 sensors. Thermal isolation: route at least 10mm of thin trace (~0.2mm) between BQ24090 thermal zone and any temperature-sensitive component. - ISET pin: connect to R3 (1.8kΩ) to set Icharge ≈ 494mA (C/4 for 2000mAh) - PRETERM pin: connect to R2 (5.1kΩ — keep existing value, sets termination threshold) - ISET2 pin: connect per datasheet recommendation (typically VSYS or VBAT) - TS pin: connect to R4 (10kΩ NTC thermistor or static resistor to GND) If using static resistor: 10kΩ to GND disables thermal protection RECOMMENDATION: add NTC 10kΩ B=3950 near battery for thermal protection - CHG# (open drain): connect to LED_RED via 330Ω to VCC, and to U1 IO2 via 10kΩ - PG# (open drain): connect to LED_GREEN via 330Ω to VCC, and to U1 IO3 via 10kΩ - OUT pin: VBAT rail (to battery positive and to LDO input) **LDO1 — ME6211C33M5G-N** (Nanjing Micro One, LCSC C82942) - LDO regulator, Vin 2.0–6.0V → Vout 3.3V fixed - Package: SOT-23-5, 2.9×1.6mm - Quiescent current: 55µA (higher than MCP1700, but adequate) - Dropout: 300mV @ 100mA - CE pin: connect to VCC (always enabled) or to ESP32 GPIO for power gating - THERMAL NOTE: at full system load (~100mA), dissipation = (Vbat-3.3)×0.1 ≈ 40–90mW. Low risk, but keep minimum 5mm from SHT40 sensors. - Vin decoupling: C2 1µF + C1 100nF - Vout decoupling: C3 10µF (electrolytic or ceramic) + additional 100nF ceramic **O1 — SI2301CDS** (Vishay, LCSC C10487) - P-channel MOSFET, Vds=-20V, Id=-3A, Vgs(th)=-0.4V typ - Package: SOT-23, 2.9×1.6mm - PURPOSE: load switch between VBAT and LDO1 input, controlled by ESP32 This allows the ESP32 to cut power to all sensors during deep sleep for maximum battery life (if desired — optional feature) - Gate connection: 10kΩ pull-up resistor from Gate to VBAT (MOSFET OFF by default) + GPIO IO4 from ESP32 drives Gate to GND through 1kΩ series resistor to turn ON IMPORTANT: this was missing from previous schema — gate must NOT float. Series 1kΩ on gate limits gate charge current and protects GPIO. Pull-up 10kΩ to VBAT ensures MOSFET stays OFF during ESP32 boot/reset. - Source: VBAT (battery positive) - Drain: LDO1 VIN ### Connectors and Passive Components **J1 — USBC_C165948** (USB Type-C SMD receptacle, LCSC C165948) - USB-C connector for 5V power input and ESP32 programming - Position: TOP EDGE of head section (accessible when device is in soil) - VBUS pins → BQ24090 IN (via R_protection 1Ω/1A fuse resistor optional) - D+ → ESP32 IO19, D- → ESP32 IO18 - GND → GND plane - All CC pins → GND via 5.1kΩ resistors (CC1: R_CC1 5.1kΩ, CC2: R_CC2 5.1kΩ) These are MANDATORY for USB-C to deliver 5V (tells charger it is a sink device) WITHOUT these resistors the USB-C port will NOT receive power from modern chargers. **U_BAT — LiPo 2000mAh connector** - Use JST PH 2.0mm 2-pin connector (standard LiPo connector) - Position: head section, easily accessible for battery replacement - Polarity protection: the SI2301 load switch also provides polarity protection if wired with Source=Drain correctly (P-FET body diode blocks reverse current) **R1 — 4.7kΩ ±1% 0402** (CHANGED from 5.1kΩ in previous schema) - I2C SDA pull-up: connects VCC to SDA bus - Reason for change: 4.7kΩ is the standard I2C pull-up value per NXP I2C spec. 5.1kΩ causes slower rise times at 400kHz fast-mode, risking data errors. **R2 — 4.7kΩ ±1% 0402** (CHANGED from 5.1kΩ in previous schema) - I2C SCL pull-up: connects VCC to SCL bus **R3 — 1.8kΩ ±1% 0402** - BQ24090 ISET: sets charge current to ~494mA (Ichg = 890/R3) **R4 — 10kΩ 0402** - BQ24090 TS pin bias or NTC resistor (see BQ24090 notes above) **R5, R6 — 5.1kΩ 0402** (NEW — not in previous schema) - USB-C CC1 and CC2 pull-down resistors (MANDATORY for USB-C power delivery) **R7 — 10kΩ 0402** (NEW) - SI2301 Gate pull-up to VBAT **R8 — 1kΩ 0402** (NEW) - SI2301 Gate series resistor from ESP32 GPIO IO4 **R9, R10 — 330Ω 0402** (NEW) - Current limiting for LED_RED and LED_GREEN (status LEDs) **C1 — 100nF 0402 X5R** — LDO Vin decoupling **C2 — 1µF 0402 X5R** — LDO Vin bulk **C3 — 10µF 0805 X5R** — LDO Vout bulk **C4 — 100nF 0402** — ESP32 VCC decoupling **C5–C9 — 100nF 0402** — Per-IC VCC decoupling (one per U2/U3/U4/U5/U8) **C10 — 4.7µF 0402** — BQ24090 IN bypass **C11 — 4.7µF 0402** — BQ24090 OUT bypass **LED1 — Green 0402** — USB power good / charging complete indicator **LED2 — Red 0402** — Charging in progress indicator **BTN1 — 3×3mm SMD tactile switch** (optional, recommended) - Connected between ESP32 EN pin and GND, with 100nF debounce cap - Allows manual reset without USB for field use --- ## ELECTRICAL NETS SUMMARY | Net Name | Description | Connected to | |----------|-------------|--------------| | VBUS_5V | USB-C 5V input | J1 VBUS, BQ24090 IN | | VBAT | Battery voltage 3.2–4.2V | U_BAT+, BQ24090 OUT, O1 Source | | VCC | Regulated 3.3V | LDO1 OUT, all IC VDD/VCC pins | | GND | Common ground | All GND pins, copper pour both layers | | SDA | I2C data (main bus) | ESP32 IO8, TCA9548A SDA_A, VEML7700 SDA, FDC1004 SDA, R1 pull-up | | SCL | I2C clock (main bus) | ESP32 IO9, TCA9548A SCL_A, VEML7700 SCL, FDC1004 SCL, R2 pull-up | | SDA_CH0 | I2C mux channel 0 | TCA9548A SD0, SHT40-internal SDA | | SCL_CH0 | I2C mux channel 0 | TCA9548A SC0, SHT40-internal SCL | | SDA_CH1 | I2C mux channel 1 | TCA9548A SD1, SHT40-external SDA | | SCL_CH1 | I2C mux channel 1 | TCA9548A SC1, SHT40-external SCL | | SOIL_A | Soil electrode set A | FDC1004 CIN1, interdigital traces prong (even fingers) | | SOIL_B | Soil electrode set B | FDC1004 CIN2, interdigital traces prong (odd fingers) | | USB_DP | USB D+ | J1 D+, ESP32 IO19 | | USB_DM | USB D- | J1 D-, ESP32 IO18 | | CHG_STATUS | Charger status | BQ24090 CHG#, LED_RED, ESP32 IO2 | | PG_STATUS | Power good | BQ24090 PG#, LED_GREEN, ESP32 IO3 | | LOAD_EN | Load switch control | ESP32 IO4 via R8, SI2301 Gate | --- ## PARASITIC AND SIGNAL INTEGRITY CONSTRAINTS Please consider the following parasitic effects when placing components and routing: **I2C bus parasitics:** The I2C specification allows maximum 400pF total bus capacitance. With 4 devices on the main bus (ESP32, VEML7700, FDC1004, TCA9548A) plus the multiplexed sub-buses, keep total SDA/SCL trace length under 50mm. Route SDA and SCL as a parallel differential pair with 0.15mm clearance between them. Do not route I2C traces near switching power lines or under the antenna keep-out zone. **FDC1004 CIN1/CIN2 parasitic capacitance — CRITICAL:** Any stray capacitance on CIN1/CIN2 traces directly offsets the soil measurement. Each picofarad of parasitic capacitance reduces measurement range. Requirements: - Keep CIN1/CIN2 trace length under 15mm from FDC1004 pins to prong entry point - Route on Bottom layer only, no layer changes (vias add ~0.5pF each) - Add copper guard ring (connected to SHLD1/SHLD2=GND) completely surrounding each CIN trace on the same layer — this shields the trace from external fields - Maintain 0.5mm spacing between CIN1 trace and CIN2 trace (and their guard rings) - The interdigital soil electrodes on the prongs: finger width 0.8mm, gap 0.8mm, finger length 25mm, approximately 15–20 alternating fingers per electrode These traces have NO soldermask (fully exposed copper, ENIG finish) **BQ24090 switching node:** The BQ24090 is a linear charger, NOT a switching regulator, so there is no switching noise. However, it dissipates power as heat. The primary constraint is thermal, not EMI. Keep input/output bypass capacitors (C10, C11) within 2mm. **ESP32-C3 antenna zone:** Mandatory keepout: no copper, no traces, no vias, no components in the area directly beneath and 3mm around the ESP32 module antenna. The antenna is on the left side of the module. Orient the module so the antenna faces toward the top or side edge of the board. **Power supply decoupling placement:** All 100nF decoupling capacitors MUST be placed within 1mm of their associated VCC/VDD pin. The parasitic inductance of a longer connection nullifies the effect. Place decoupling on the same layer as the IC where possible. The 10µF bulk cap (C3) can be up to 5mm from the LDO output. **Thermal gradients and temperature sensor placement:** The two SHT40 sensors measure temperature via an on-chip bandgap reference. Self-heating of nearby components creates a thermal offset error. Known heat sources on this board and their typical power dissipation: - BQ24090: up to 500mW during USB charging - ME6211 LDO: 40–90mW at typical load - ESP32-C3: 15–25mW in active mode (WiFi), 0.02mW in deep sleep Required minimum distances from any SHT40: - From BQ24090: ≥12mm (critical) - From ME6211 LDO: ≥8mm - From ESP32-C3: ≥5mm (less critical — low dissipation) --- ## THERMAL MANAGEMENT REQUIREMENTS The device will be used outdoors in ambient temperatures from -10°C to +50°C. The case is a sealed or semi-sealed plastic enclosure approximately 35×35×80mm. Internal temperature rise above ambient must be kept below +8°C during USB charging. **BQ24090 thermal design:** - Thermal pad (exposed pad on DSBGA package): connect to copper area on both layers - Top layer: copper fill area ≥ 1cm² directly under and around IC - Bottom layer: mirrored copper fill area ≥ 1cm² connected via thermal vias - Minimum 4 thermal vias under pad: 0.3mm drill, 0.6mm pad, evenly distributed - These thermal vias conduct heat to bottom layer copper which acts as a heatsink - In the case design (outside scope of PCB): a thermally conductive pad between the PCB bottom copper and the plastic case back wall improves heat transfer **ME6211 LDO thermal design:** - Low dissipation at typical 50–80mA load: (4.0V - 3.3V) × 0.075A ≈ 52mW - This is well within SOT-23 package limits (max ~300mW at 25°C ambient) - Standard copper pour around package is sufficient - No additional thermal vias required unless load consistently exceeds 150mA **Fire safety note:** At no point should any trace carry more than its rated current. Power traces (VBAT, VCC) should be minimum 0.5mm for up to 500mA. The USB VBUS trace from J1 to BQ24090 carries up to 500mA — use 0.8mm trace. Add a polyfuse (PTC resettable fuse) 500mA on VBUS line between J1 and BQ24090 for short-circuit protection (LCSC C178886, 0805 package). --- ## WEATHERPROOFING DESIGN GUIDANCE (for PCB layout decisions) The board will be coated with conformal coating after assembly, EXCEPT: 1. SHT40-AD1F-R2 (U8 external sensor) — the PTFE filter cap must remain uncoated 2. VEML7700 (U2) — photodiode window must remain uncoated and unobstructed 3. Interdigital soil traces on prongs — must remain bare copper (ENIG) for soil contact 4. USB-C connector J1 — coating would block the port 5. Battery JST connector — coating would block connector mating For the PCB layout, implement the following to support weatherproofing: - Place U8 (SHT40 external) and U2 (VEML7700) in designated "coating exclusion zones" clearly marked on the silkscreen layer with dashed boundary lines - Add silkscreen labels: "NO COAT" next to U8 and U2 - Add silkscreen label: "EXPOSED — SOIL ELECTRODES" on the prong traces - The board outline on the prong section must have no sharp corners — use R1mm rounded corners where prongs meet the head section to prevent cracking when the device is pushed into soil --- ## INTERDIGITAL SOIL ELECTRODE SPECIFICATION (prong section) The bottom two prongs of the board ARE the soil moisture sensor. Trace parameters for the interdigital (comb/fork) capacitive electrodes: - Layer: Bottom copper - Trace width: 0.8mm - Gap between adjacent fingers: 0.8mm - Number of fingers per electrode: 16 (8 connected to CIN1, 8 to CIN2, alternating) - Finger length: 25mm - Connection point: at the top of the prongs where they join the head section - Guard ring: GND copper guard ring around the entire interdigital pattern on Bottom layer - NO soldermask over any part of the interdigital pattern - The two electrodes (SOIL_A and SOIL_B) must be symmetrically distributed so that a uniform electric field forms between them when immersed in soil - Add stitching GND vias around the prong perimeter every 8mm --- ## SILKSCREEN AND REFERENCE DESIGNATORS All components must have visible reference designators on the silkscreen layer. Minimum text size 0.6mm height. Add the following board information: - Top left: "SmartPlant v1.0" - Top right: "riccardo.schiavo.1" - Date code placeholder: "DATE: ______" - Near J1: PIN 1 marker and "USB-C POWER + FLASH" - Near U8: "EXTERNAL SENSOR — NO COAT" - Near prong junction: "SOIL ELECTRODES — NO MASK — ENIG" - Near ESP32 antenna area: keepout boundary marker --- ## I2C DEVICE MAP (for firmware reference) | Address | Device | Bus | Notes | |---------|--------|-----|-------| | 0x10 | VEML7700 (U2) | Main I2C | Direct connection | | 0x50 | FDC1004 (U4) | Main I2C | Direct connection | | 0x70 | TCA9548A (U5) | Main I2C | I2C multiplexer | | 0x44 ch.0 | SHT40 internal (U3) | TCA9548A channel 0 | Via mux | | 0x44 ch.1 | SHT40 external (U8) | TCA9548A channel 1 | Via mux | --- ## FINAL NOTES FOR FLUX AI I trust Flux AI's judgment on: - Exact component placement optimization within the constraints above - Via placement and layer assignments for non-critical signals - Polygon fill strategy and via stitching density - Any minor trace re-routing needed to clear DRC errors - Silkscreen label exact positioning to avoid overlap with pads Please prioritize in this order: 1. Electrical correctness (no DRC errors, no antenna violations) 2. Thermal management (BQ24090 copper, SHT40 distance from heat) 3. Signal integrity (FDC1004 CIN guard rings, I2C trace length) 4. Manufacturability (SMT assembly friendly, no isolated pads, no acute angles) 5. Physical compactness within the fork shape outline Generate a complete 2-layer PCB ready for Gerber export to PCBWay.

Welcome to our cutting-edge project featuring a single-cell power bank design optimized for a robust 30,000 mAh capacity. This innovative power bank delivers a powerful USB-C output at 5V/3A, ensuring efficient charging and dependable power for all your devices. Leveraging the advanced capabilities of the Texas Instruments BQ25895 chip, the design offers superior battery charging and integrated power management. Additionally, the inclusion of a precise fuel gauge provides accurate battery level monitoring, making it ideal for users who demand reliability and performance. Experience the future of portable power with this state-of-the-art, high-capacity solution. #PowerBank #SingleCellPowerBank #30000mAh #USBC #BatteryManagement #FuelGauge #BQ25895

TPS62130 Is a Texas instrument Buck Converter IC in the TPS family of power devices. This converter has a maximum input range of...

TPS62130 Is a Texas instrument Buck Converter IC in the TPS family of power devices. This converter has a maximum input range of...

The TCA9555 is a 16-bit I/O expander, designed by Texas Instruments, that is compatible with the I2C and SMBus communication protocols. It operates between 1.65 and 5.5 volts and can be used to extend the functionality of most microcontroller families via the I2C interface. The system master can enable the I/O pins as either inputs or outputs and can invert the polarity of the Input Port register. This part is widely used in applications like servers, personal computers, automation equipment, routers, and other electronics with limited GPIO availability.

The TUSB8041, developed by Texas Instruments, is a four-port USB 3.0 hub intended for use in computer systems, docking stations, monitors, and set-top boxes, providing simultaneous SuperSpeed USB and high-speed/full-speed connections on the upstream port as well as on the downstream ports. This component supports battery charging features, enabling Charging Downstream Port (CDP) and Dedicated Charging Port (DCP) modes, compliant with the Chinese Telecommunications Industry Standard YD/T 1591-2009, and introduces an automatic mode for transparent support for BC devices and devices supporting Divider Mode charging solutions. It offers customization through OTP ROM, I2C EEPROM or via an I2C/SMBus slave interface for Vendor ID (VID), Product ID (PID), port customizations, and manufacturer and product strings. The TUSB8041 comes in a 64-pin RGC package and is available in both commercial (0°C to 70°C) and industrial (-40°C to 85°C) temperature ranges, part numbers TUSB8041 and TUSB8041I respectively, with an operating voltage requirement of 3.3V for I/O and 1.1V for the core. This hub doesn't require special drivers as it's designed to work seamlessly with any operating system supporting the USB stack, making it a highly adaptable solution for expanding USB connectivity in a wide range of applications.

The TPSM64404, TPSM64406, and TPSM64406E from Texas Instruments are highly integrated synchronous buck power modules designed for high power density and low EMI performance. These modules feature integrated MOSFETs, inductors, and controllers within a compact 6.5mm × 7.0mm × 2mm overmolded package, making them ideal for space-constrained applications. They support a wide input voltage range of 3V to 36V and deliver adjustable output voltages from 0.8V to 16V. The TPSM64404 offers dual 2A outputs or a stackable 4A output, while the TPSM64406 and TPSM64406E provide dual 3A outputs or a stackable 6A output, with the TPSM64406E rated for extended temperature ranges down to -55℃. These modules achieve peak efficiencies exceeding 93.5% and feature ultra-low quiescent current, making them suitable for battery-powered applications. Designed to meet stringent EMI standards, the modules include features such as dual input paths, integrated capacitors, spread spectrum modulation, and low-noise packaging. Additional functionalities include precision enable inputs, power-good indicators, overcurrent protection, thermal shutdown, and the ability to configure for multiphase operation up to 18A. The TPSM6440xx series is optimized for test and measurement, aerospace, defense, and factory automation applications.

Texas Instruments' TPSM6440xx series, including the TPSM64404, TPSM64406, and TPSM64406E, are highly integrated synchronous buck power modules designed for applications requiring high power density and low EMI. These modules support dual output or multiphase single output configurations, operating over a wide input voltage range from 3V to 36V and delivering adjustable output voltages from 0.8V to 16V. Encased in a compact 6.5mm x 7.0mm x 2mm overmolded package, they feature integrated MOSFETs, inductors, and controllers, ensuring ease of design and high efficiency with peak performance exceeding 93.5%. The TPSM6440xx modules are optimized for low noise and EMI, meeting CISPR 11 and 32 Class B emissions standards. They include robust protection features like precision enable inputs, power good indicators, overcurrent, and thermal shutdown protections, making them suitable for demanding applications in test and measurement, aerospace, defense, and factory automation. With a flexible design approach, these modules can be easily configured using Texas Instruments' WEBENCH® Power Designer tool.

The OPA835 and OPA2835 from Texas Instruments are ultra-low-power, rail-to-rail output, voltage-feedback (VFB) operational amplifiers. Designed for high-performance applications, these single (OPA835) and dual (OPA2835) op-amps operate over a power supply range of 2.5 V to 5.5 V. Consuming a mere 250 µA per channel, they offer a remarkable balance of power efficiency and performance, boasting a unity-gain bandwidth of 56 MHz, a slew rate of 160 V/µs, and ultra-low THD of 0.00003% at 1 kHz. Key features include a large signal bandwidth, negative rail input, power-down mode reducing current to 0.5 µA, and input voltage noise of 9.3 nV/√Hz at 100 kHz. Packaged options such as SOT-23, QFN, SOIC, VSSOP, and UQFN are available, accommodating a range of design requirements. The devices are ideal for battery-powered and portable applications, offering superior performance-to-power ratios for high-frequency amplifiers.

The L293 and L293D, manufactured by Texas Instruments, are quadruple high-current half-H drivers designed to drive inductive loads such as relays, solenoids, DC, and bipolar stepping motors, among other high-current/high-voltage loads in positive-supply applications. These components cater to a wide supply-voltage range from 4.5 V to 36 V. The L293 can provide bidirectional drive currents of up to 1 A, whereas the L293D variant supports up to 600 mA, incorporating output clamp diodes for inductive transient suppression. With separate input-logic supply, their internal architecture enables high noise immunity and low power dissipation. These drivers are enabled in pairs, with the enable input controlling the state of the drivers, which are designed to work in high-impedance states when disabled. Markedly, the L293D is distinctively packaged with internal ESD protection and a thermal shutdown feature to safeguard against excessive heat and electric static discharge, ensuring reliability and stability in operation. Collectively, the L293 and L293D are functionally similar to SGS L293 and L293D and are characterized for operation from 0℃ to 70°C, structured to meet a broad array of motor driving requirements with their robust design and advanced features.

The OPAx863 series from Texas Instruments includes the OPA863, OPA2863, and OPA4863, which are low-power, rail-to-rail input/output, voltage-feedback operational amplifiers designed for high-performance applications. These amplifiers feature a unity-gain bandwidth of 110 MHz, a gain-bandwidth product of 50 MHz, and a low quiescent current of 700 µA per channel. The devices operate across a wide supply voltage range of 2.7 V to 12.6 V, making them suitable for both portable and battery-powered systems. With a slew rate of 105 V/µs, 5.9 nV/√Hz input voltage noise, and exceptional harmonic distortion performance (-129 dBc HD2, -138 dBc HD3 at 20 kHz for 2 Vpp output), the OPAx863 is adept for driving SAR and ΔΣ ADCs, acting as ADC reference buffers, low-side current sensing, photodiode TIA interfaces, and other high-precision tasks. Additional features include overload power limiting, output short-circuit protection, and a power-down mode with minimal quiescent current, making the OPAx863 series a versatile and robust choice for applications requiring low power and high-precision analog performance. The series includes single, dual, and quad-channel configurations available in various surface-mount packages to fit different design requirements.

The Texas Instruments OPA863, OPA2863, and OPA4863 are low-power, voltage-feedback operational amplifiers designed to offer a unity-gain stable, rail-to-rail input and output with a 110-MHz bandwidth. These amplifiers are optimized for a broad power supply range from 2.7 V to 12.6 V, catering to a variety of portable and battery-powered applications. Key features include a quiescent current of 700-uA/ch (typical), a gain-bandwidth product of 50 MHZ, input voltage noise of 5.9-nV/VHz, and a slew rate of 105-V/us. The series also highlights specialized versions including the OPAx863A for high precision requirements, and all models integrate features like overload power limit and output short-circuit protection for ruggedized environments. The devices’ applicability spans across multiple domains including low-power SAR and ΔΣ ADC drivers, ADC reference buffers, photodiode transimpedance amplifiers, and more. The comprehensive array of packages available (including SOT-23, VSSOP, WQFN, and TSSOP options) ensures flexibility in hardware design, making these operational amplifiers from Texas Instruments suitable for high-performance, space-conscious, and power-sensitive electronic circuits.

This project is a reference design for a VL53L1X-based sensor circuit. It incorporates the use of a Texas Instruments LP5907MFX-2.8/NOPB to regulate the supply voltage. #referenceDesign #VL53L1X #project #template #LIDAR #sensor #distance #referenceDesign #industrialsensing #stm #template #reference-design #polygon

This project is a reference design for a VL53L0CXV0DH-based sensor circuit. It incorporates the use of a Texas Instruments LP5907MFX-2.8/NOPB to regulate the supply voltage. #referenceDesign #VL53L0 #project #template #LIDAR #sensor #distance #referenceDesign #industrialsensing #stm #template #reference-design #polygon

The TCA9555 by Texas Instruments is a low-voltage, 16-bit I2C and SMBus I/O expander designed to provide general-purpose remote I/O expansion for most microcontroller families via the I2C interface. Operating at a voltage range of 1.65V to 5.5V, this component integrates two 8-bit Configuration, Input Port, Output Port, and Polarity Inversion registers, making it an ideal solution for applications requiring additional I/Os such as servers, personal computers, routers, industrial automation equipment, and products with GPIO-limited processors. The TCA9555 features a low standby-current consumption of 3.5uA maximum, compatibility with 5V I/O ports, a 400kHz Fast I2C Bus, and includes an open-drain active-low interrupt output which enhances its utility in complex systems. Noteworthy for its high-current drive capability suitable for directly driving LEDs, the TCA9555 also brings a configurable slave address with 3 address pins, providing the flexibility needed in varied application requirements. Offering robust protection with latch-up performance exceeding 100mA per JESD 78, Class II, and ESD protection exceeding JESD 22, the TCA9555 combines reliability with expansive functionality for sophisticated electronic designs.

This project is a reference design for a VL6180X-based sensor circuit. It incorporates the use of a Texas Instruments LP5907MFX-2.8/NOPB to regulate the supply voltage. #referenceDesign #VL6180X #project #template #LIDAR #sensor #distance #referenceDesign #industrialsensing #stm #template #reference-design #polygon

DIP825W47P254L1917H533Q14 PDIP-14 Texas Instruments LM324N 4-Channel industry standard operational amplifier 14-PDIP 0 to 70 https://pricing.snapeda.com/search/part/LM324N/?ref=eda Texas Instruments None In Stock Aliases: undefined

DIP825W47P254L1917H533Q14 PDIP-14 Texas Instruments LM324N 4-Channel industry standard operational amplifier 14-PDIP 0 to 70 https://pricing.snapeda.com/search/part/LM324N/?ref=eda Texas Instruments None In Stock Aliases: undefined

DIP825W47P254L1917H533Q14 PDIP-14 Texas Instruments LM324N 4-Channel industry standard operational amplifier 14-PDIP 0 to 70 https://pricing.snapeda.com/search/part/LM324N/?ref=eda Texas Instruments None In Stock Aliases: undefined

DIP825W47P254L1917H533Q14 PDIP-14 Texas Instruments LM324N 4-Channel industry standard operational amplifier 14-PDIP 0 to 70 https://pricing.snapeda.com/search/part/LM324N/?ref=eda Texas Instruments None In Stock Aliases: undefined

DIP825W47P254L1917H533Q14 PDIP-14 Texas Instruments LM324N 4-Channel industry standard operational amplifier 14-PDIP 0 to 70 https://pricing.snapeda.com/search/part/LM324N/?ref=eda Texas Instruments None In Stock Aliases: undefined

DIP825W47P254L1917H533Q14 PDIP-14 Texas Instruments LM324N 4-Channel industry standard operational amplifier 14-PDIP 0 to 70 https://pricing.snapeda.com/search/part/LM324N/?ref=eda Texas Instruments None In Stock Aliases: undefined

DIP825W47P254L1917H533Q14 PDIP-14 Texas Instruments LM324N 4-Channel industry standard operational amplifier 14-PDIP 0 to 70 https://pricing.snapeda.com/search/part/LM324N/?ref=eda Texas Instruments None In Stock Aliases: undefined

DIP825W47P254L1917H533Q14 PDIP-14 Texas Instruments LM324N 4-Channel industry standard operational amplifier 14-PDIP 0 to 70 https://pricing.snapeda.com/search/part/LM324N/?ref=eda Texas Instruments None In Stock Aliases: undefined

DIP825W47P254L1917H533Q14 PDIP-14 Texas Instruments LM324N 4-Channel industry standard operational amplifier 14-PDIP 0 to 70 https://pricing.snapeda.com/search/part/LM324N/?ref=eda Texas Instruments None In Stock Aliases: undefined

DIP825W47P254L1917H533Q14 PDIP-14 Texas Instruments LM324N 4-Channel industry standard operational amplifier 14-PDIP 0 to 70 https://pricing.snapeda.com/search/part/LM324N/?ref=eda Texas Instruments None In Stock Aliases: undefined

DIP825W47P254L1917H533Q14 PDIP-14 Texas Instruments LM324N 4-Channel industry standard operational amplifier 14-PDIP 0 to 70 https://pricing.snapeda.com/search/part/LM324N/?ref=eda Texas Instruments None In Stock Aliases: undefined

DIP825W47P254L1917H533Q14 PDIP-14 Texas Instruments LM324N 4-Channel industry standard operational amplifier 14-PDIP 0 to 70 https://pricing.snapeda.com/search/part/LM324N/?ref=eda Texas Instruments None In Stock Aliases: undefined