General Description
The AS8267 / AS8268 are highly integrated CMOS single-phase energy metering devices for fully electronic LCD meter systems. The AS8267 / AS8268 have been designed to ensure a meters full compliance with the international Standards IEC62052 and ANSI.

Key Features
- Precision single-phase, one or two current input energy measurement front-end including SigmaDelta modulators for A/D-conversion and digital signal processor (DSP).
- Low current consumption of 5mA, depending on MCU activity.
- Digital phase correction and selectable gain on both current channels for use with two current transformers (CT) or one CT and one shunt.
- Power-supply monitor (PSM) for power-on reset and reset when the supply voltage falls below a defined threshold.
- Customer programmable 8-bit 8051 compatible microcontroller (MCU).
- Programmable MCU clock for optional low power operating conditions.
- Highly reliable 32kBytes of non-volatile Flash memory is provided on-chip for storage of both program and data.
- Program and data security is provided by optional password and attack counter protection.
- 2 x Universal Asynchronous Receiver / Transmitters (UART) for external communications such as programme download and debugging.
- Programmable watchdog timer (WDT) and external system reset pin.
- Real-time clock/calendar (RTC) with on-chip digital calibration and separate battery supply pin.
- On-chip temperature sensor for optional temperature compensation.
- On-chip voltage reference (VREF) with small temperature coefficient (15ppm/K typ.).
- Low power 3.0 – 4.0MHz crystal oscillator.
- SPI compatible interface for optional external non-volatile EEPROM memory selectable up to 32kBytes.
- Mains current lead/lag status indication for reactive energy measurement.
- Low power battery operating mode for meter reading when Mains voltage is not present.
- AS8267: 20 x 4 segment LCDD 9 x multi-purpose I/O (MPIO)
- AS8268: 24 x 4 segment LCDD 12 x multi-purpose I/O (MPIO)