IoT

**IoT Semiconductor Ultra-Low Power** is **semiconductor devices consuming microwatts enabling battery operation for years in wireless sensors and edge devices** — power is critical constraint. **Energy Harvesting** devices powered by ambient energy (solar, RF, vibration, thermal). Reduce battery dependence. **Sleep Modes** most of time in sleep (microamps). Wake periodically (milliseconds awake). **Duty Cycle** 0.1-1% duty cycle typical: sleep 99%, active 1%. **Power Consumption Hierarchy** CPU >> RF >> sensors >> memory. Optimization focuses on heaviest consumers. **Processor Selection** ARM Cortex-M0+ (ultra-low power), Cortex-M3/M4. MHz-range speeds adequate. **RF Module** Bluetooth Low Energy (BLE), LoRaWAN, ZigBee. Optimized for low power. Idle current microamps. **Sleep Current Leakage** semiconductor leakage in sleep; total power (active + sleep). Leakage increasingly important. **Wakeup Latency** transitioning from sleep to active takes time/energy. Balance wake speed vs. sleep depth. **Memory** SRAM power critical; FLASH non-volatile but slower. **Sensor Power** sensors themselves consume power (always-on accelerometer for activity detection vs. sleeping accelerometer). **Wireless Protocol** shorter packets, less frequent transmission reduce power. **Battery Technology** alkaline AAs typical; rechargeable (Li-ion) for harsh environments. **Battery Voltage** decreasing supply voltage (2.7V down from 3.3V); regulators less efficient. **Transducer Efficiency** data transmission most power-expensive. Compression, filtering reduce. **RF Power** RF transmit dominates. Higher power for range; lower for local. **Network** mesh networking extends range via relays. **Cloud** edge computing: process locally, send only results. **Wake Sensors** passive infrared (PIR) triggers wake; ultra-low power. **Accelerometers** MEMS accelerometer detects motion; wakes device. **Time-to-Live** system lifetime (battery + harvesting) years to decades. **Lifetime Prediction** Weibull analysis estimates reliability. **Product Examples** fitness trackers, environmental sensors, door locks, security tags. **Emerging** millimeter-scale devices (motes). **IoT semiconductors enable ubiquitous computing** through ultra-low power design.