A compact battery-powered door/window sensor built around the ESP32-C3-MINI-1-N4 module. The design uses a single non-rechargeable AA cell with a TPS613221A 3.3 V boost regulator, reed switch magnetic contact sensing, low-power wake/report/sleep firmware strategy, RGB status LED for setup feedback, BOOT/EN controls, programming header, and input polarity protection. It is intended for smart-home security and automation applications, supporting WiFi or Bluetooth LE hub reporting with emphasis on low idle current, reliable RF burst power delivery, and field-replaceable battery operation. #ESP32-C3 #BLE #WiFi #DoorSensor #WindowSensor #ReedSwitch #LowPower #BatteryPowered #SmartHome #IoT

Low-power USB-C 5V environmental sensor node with ESP32-S3 WiFi/BLE, digital temperature/humidity sensing, protected 5V input path, and 3.3V regulation.

Solar-powered dashboard compass for an FJ with a 3-digit seven-segment direction display, magnetometer sensing, low-power MCU control, rechargeable battery storage, and solar charging.

USB-C powered consumer environmental sensor node with ESP32-class Wi‑Fi/BLE connectivity, digital temperature/humidity sensing, protected 5 V input, and low-power 3.3 V electronics.

Consumer USB-C powered environmental sensor node with ESP32-class Wi-Fi/BLE, digital temperature/humidity sensing, protected 5 V input, and low-power 3.3 V architecture.

Consumer USB-C powered low-power environmental sensor node with digital temperature/humidity sensing, ESP32-class Wi-Fi/BLE 5.x connectivity, and protected 5V USB-C input for 0.5–3A sources.

Consumer USB-C powered low-power environmental sensor node with WiFi/BLE MCU, digital temperature/humidity sensing, USB-C 5 V input, and input protection for 0.5–3 A sources.

USB-C powered low-power environmental sensor node with ESP32 Wi-Fi/Bluetooth, digital temperature/humidity sensing, and protected 5 V input for consumer use.

USB-C powered low-power environmental sensor node with ESP32-class Wi-Fi/BLE, digital temperature/humidity sensing, USB-C 5V sink input, and protected 3.3V power rail.

Consumer USB-C powered low-power environmental sensor node with Wi-Fi, Bluetooth LE, digital temperature/humidity sensing, and protected 5 V input supporting 0.5–3 A USB-C sources.

USB-C powered low-power consumer environmental sensor node with Wi-Fi/Bluetooth connectivity, digital temperature/humidity sensing, protected 5 V input, and 3.3 V system rail.

Low-power USB-C environmental sensor node with ESP32 Wi-Fi/BLE, digital temperature/humidity sensing, and protected 5 V input power path.

Low-power consumer environmental sensor node with ESP32-S3 Wi-Fi/BLE, digital temperature/humidity sensing, USB-C 5 V default-sink input, reverse/OVP/UVLO/OCP protection, and regulated 3.3 V power for 0.5–3 A USB-C sources.

The LTC3109 from Linear Technology is a highly integrated DC/DC converter specifically designed for energy harvesting applications. It can operate from ultra-low input voltages as low as 30mV, utilizing a unique, proprietary auto-polarity architecture to function regardless of input polarity. The component is ideal for harvesting energy from thermoelectric generators (TEGs) and thermopiles, efficiently converting this energy to power remote sensors, wireless transmitters, and low-power devices. Key features include selectable output voltages of 2.35V, 3.3V, 4.1V, or 5V, a 2.2V low-dropout (LDO) regulator, a logic-controlled output, and an energy storage system to maintain operation during power interruptions. The LTC3109 is encapsulated in a small, 20-lead (4mm × 4mm) QFN or SSOP package, making it compact and suitable for space-constrained applications in HVAC systems, building automation, and industrial wireless sensing. Additionally, the power good indicator and the ability to use compact step-up transformers further enhance its suitability for low power, energy-harvesting systems.

Low-power USB-C powered environmental sensor node with Wi-Fi 802.11 b/g/n, BLE 5.x, digital temperature/humidity sensing, and protected 5 V USB-C input for 0.5–3 A sources.

USB-C powered low-power temperature and humidity sensor node with WiFi, Bluetooth LE, protected 5 V input, and digital environmental sensing.

USB-C powered low-power temperature/humidity sensor node with ESP32-class Wi‑Fi/BLE 5.x connectivity, digital T/RH sensing, USB-C 5 V sink input, and protected 3.3 V power path sized for 0.5–3 A sources.

Low-power USB-C environmental sensor node using a dual-radio Wi‑Fi/BLE MCU, digital temperature/humidity sensing, protected 5 V USB-C input, and 3.3 V regulation for consumer use.

Low-power consumer environmental sensor node with USB-C 5V input, Wi-Fi + Bluetooth connectivity, digital temperature/humidity sensing, and protected 5V-to-3.3V power architecture including reverse, OVP, UVLO, and OCP considerations.

USB-C powered low-power environmental sensor node with Wi-Fi, Bluetooth LE, protected 5 V input, 3.3 V regulation, and digital temperature/humidity sensing for consumer use.

Consumer USB-C powered low-power temperature and humidity sensor node with Wi-Fi/BLE connectivity, I2C digital T/RH sensing, and protected 5 V input power management.

Low-power USB-C 5V environmental sensor node with robust input protection, ESP32 Wi-Fi/BLE connectivity, digital temperature/humidity sensing, Bluetooth peripheral syncing, and EEG/PPG sensor interfaces for prototype biosignal acquisition.

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 ADA4084-1, ADA4084-2, and ADA4084-4, manufactured by Analog Devices, Inc., are a series of low-power, rail-to-rail input/output operational amplifiers designed to operate from a single supply voltage ranging from +3 V to +30 V (or ±1.5 V to ±15 V). These amplifiers are characterized by their low noise performance (3.9 nV/√Hz at 1 kHz typical), low offset voltage (100 uV maximum for the SOIC package), and low power consumption (0.625 mA typical per amplifier at +15 V). With a gain bandwidth product of 15.9 MHz and a slew rate of 4.6 V/μs typical, these amplifiers are suitable for a broad range of applications, including battery-powered instrumentation, high-side and low-side sensing, power supply control and protection, and telecommunications among others. The ADA4084 series is available in various package options, ensuring flexibility and compatibility for different design requirements. Notably, the long-term drift and temperature hysteresis are meticulously engineered for consistent performance over time and across temperature variations, making these amplifiers robust choices for applications demanding precision and stability.