The AS8218 / AS8228 are highly integrated CMOS single-phase energy metering devices for fully electronic LCD meter systems. The AS8218 / AS8228 have been designed to ensure the meters full compliance with the international Standards IEC6052 and ANSI.

The AS8218 / AS8228 ICs include all the functions required for conventional 1- or 2-current anti-tamper meters. The functions include precision energy measurement, an 8-bit microcontroller unit (MCU), an on-chip Liquid Crystal Display driver (LCDD), programmable multipurpose Inputs/Outputs (MPIO), a real time clock/calendar (RTC) for complex tariff functions such as time-of-use or maximum demand billing and a Serial Peripheral Interface (SPI) for reading data from and writing data to an external non-volatile memory (EEPROM).

The AS8218 / AS8228 ICs have a dedicated energy measurement front-end, which includes an analog front-end and programmable Digital Signal Processor (DSP) from which active energy, mains voltage and mains current are provided. Reactive and apparent energy can also be calculated.

The on-chip 8-bit 8051 compatible microcontroller is freely programmable and provides user access to the various functional blocks. The dedicated Universal Asynchronous Receiver / Transmitter (UART1) in the System Control block provides access to various system functions and blocks. A second UART (UART2) is also provided, which may for example be used for debugging. The on-chip memory includes 24kByte program memory and 1kByte data memory. The meter system designer can select the size of the external EEPROM memory, from 1kByte to 32kByte (in binary steps).