FDS_6533_6534_004
71M6533/71M6534 Data Sheet
1 Hardware Description
1.1 Hardware Overview
The Teridian 71M6533 and 71M6534 single-chip energy meter integrate all primary functional blocks re-
quired to implement a solid-state electricity meter. Included on the chip are:
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An analog front end (AFE)
An Independent digital computation engine (CE)
An 8051-compatible microprocessor (MPU) which executes one instruction per clock cycle (80515)
A voltage reference
A temperature sensor
LCD drivers
RAM and Flash memory
A real time clock (RTC)
A variety of I/O pins
Various current sensor technologies are supported including Current Transformers (CT), Resistive Shunts
and Rogowski coils.
In a typical application, the 32-bit compute engine (CE) of the 71M6533/71M6534 sequentially processes
the samples from the voltage inputs on analog input pins and performs calculations to measure active
energy (Wh) and reactive energy (VARh), as well as A2h, and V2h for four-quadrant metering. These
measurements are then accessed by the MPU, processed further and output using the peripheral devices
available to the MPU.
In addition to advanced measurement functions, the real time clock function allows the 71M6533/71M6534
to record time of use (TOU) metering information for multi-rate applications and to time-stamp tamper
events. Measurements can be displayed on 3.3 V LCDs commonly used in low-temperature environ-
ments. Flexible mapping of LCD display segments facilitate integration of existing custom LCDs. Design
trade-off between the number of LCD segments and DIO pins can be implemented in software to ac-
commodate various requirements.
In addition to the temperature-trimmed ultra-precision voltage reference, the on-chip digital temperature
compensation mechanism includes a temperature sensor and associated controls for correction of un-
wanted temperature effects on measurement and RTC accuracy, e.g. to meet the requirements of ANSI
and IEC standards. Temperature dependent external components such as a crystal oscillator, current
transformers (CTs) and their corresponding signal conditioning circuits can be characterized and their
correction factors can be programmed to produce electricity meters with exceptional accuracy over the
industrial temperature range.
One of the two internal UARTs is adapted to support an Infrared LED with internal drive and sense confi-
guration and can also function as a standard UART. The optical output can be modulated at 38 kHz.
This flexibility makes it possible to implement AMR meters with an IR interface. A block diagram of the IC
is shown in Figure 1.
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© 2007-2009 TERIDIAN Semiconductor Corporation
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TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
