AS8267 Datasheet, PDF (1/136 Pages) ams AG – Single-Phase 2-Current Energy Measurement Integrated Circuits with Microcontroller, RTC, Programmable Multi-Purpose I/Os

AS8267 / AS8268
Single-Phase 2-Current Energy Measurement Integrated Circuits
with Microcontroller, RTC, Programmable Multi-Purpose I/Os,
LCD Driver and On-Chip FLASH Memory
DATA SHEET
1. Key Features
- Precision single-phase, one or two current input
energy measurement front-end including Sigma-
Delta 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)
2. 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.
The AS8267 / AS8268 ICs include all the functions
required for conventional 1 current or 2-current
anti-tamper meters. The functions include precision
energy measurement, an 8-bit microcontroller unit
(MCU) with 32kBytes of Flash memory, an on-chip
Liquid Crystal Display driver (LCDD),
programmable multi-purpose 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 optional external non-volatile memory
(EEPROM).
The AS8267 / AS8268 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 allows 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 32kByte of highly reliable non-
volatile Flash program (and data) memory and
Revision 1.0, 19-Jun-07
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