General Features Wide supply voltage operation: 2.4 V to 3.7 V Internal bipolar switch between regulated and battery inputs Ultralow power operation with power saving modes (PSM) Reference 1.2 V ± 1% (drift 50 ppm/°C Maximum) 64-Lead Quad Flat (LQFP) or Chip Scale (LCSP) Lead Free Packages Operating Temperature -40°C to 85°C Energy Measurement Features Proprietary ADCs and DSP provide high accuracy active, reactive, and apparent energy measurement Supports IEC 62053-21, IEC 62053-22, IEC 62053-23, EN 50470-3 Class A, Class B, and Class C, and ANSI C12-16 Differential input with PGAs supports shunts and current transformers High frequency outputs proportional to Irms, active or apparent power (AP) MicroProcessor Features Single-cycle 4MIPS 8052 core 32.768 kHz external crystal with on-chip PLL Low power battery mode Wake-up from I/O, temperature change, alarm, and UART LCD driver operation Temperature measurement Real-time clock Counter for seconds, minutes, and hours Automatic battery switchover for RTC backup Ultralow battery supply current: 1.5 ?A Selectable output frequency: 1Hz to 16.384 kHz Embedded digital crystal frequency compensation for calibration and temperature variation 2 ppm resolution Integrated LCD driver 108-segment LCD voltages generated internally or with external resistors Internal adjustable drive voltages up to 5 V independent of power supply level On-chip peripherals UART, SPI or I2C, watchdog timer Memory: 16 kB flash memory, 512 bytes RAM