AT73C502

Features:

• Fulfills IEC 1036, Class 1 Accuracy Requirements
• Fulfills IEC 687, Class 0.5 and Class 0.2 Accuracy, with External Temperature Compensated Voltage Reference
• Simultaneous Active, Reactive and Apparent Power and Energy Measurement
• Power Factor, Frequency, Voltage and Current Measurement
• Single and Poly Phase Operation
• Three Basic Operating Modes: Stand-Alone Mode, Microprocessor Mode and MultiChannel Mode
• Flexible Interfacing, 8-bit Microprocessor Interface, 8-bit Status Output and Eight Impulse Outputs
• Calibration of Gain and Phase Error
• Compensation of the Non-Linearity of Low Power Measurement
• Adjustable Starting Current and Meter Constant
• Measurement Bandwidth of 1000 Hz
• Tamper Proof Design
• Single +5V Supply



Pinout




Specifications

Parameter	Min	Typ	Max	Unit
Supply Voltage VCC,VDA, VDDA	4.75		5.25	V
Input Voltage, Digital	-0.3		VDD +0.3	V
Input Voltage, Analog	-0.3		VDA+0.3	V
Input Voltage, CI and VI inputs	1.25		3.75	V
Ambient Operating Temp.	-25		+70	C
Storage Temperature	-65		+150	C

Description

A two chip solution, consisting of AT73C500 and AT73C501 (or AT73C502), offers all main features required for the measurement and calculation of various power and energy quantities in static Watt-hour meters. The devices operate according to IEC1036, class 1, specification. IEC 687, class 0.5 and 0.2 requirements are fulfilled when used with external temperature compensated voltage reference.

The AT73C502 contains six, high-performance, Sigma-Delta analog-to-digital converters (ADC). The AT73C500 is based on an efficient digital signal processor (DSP) core and it supports interfacing both with the AT73C501 and with an external microprocessor. The AT73C500 DSP can also be used with the differential input ADC, AT73C502. With this chipset, only a minimum of discrete components is required to develop products ranging from simple domestic Watt-hour meters to sophisticated industrial meters. The chipset can be used in single-phase as well as in poly-phase systems.

The DSP core of the AT73C502 is easy to configure. By changing the mode of the AT73C500, the device can be operated in a stand-alone environment or be used with a separate control processor. It is also possible to configure the circuit to perform the functions of three independent single phase Wh meters. The chips support calibration of gain and phase error. All calibrations are done in the digital domain and no trimming components are needed. The calibration coefficients are either stored in an EEPROM memory or supplied by an external microp-rocessor.

The AT73C502 is programmed to measure active, reactive and apparent phase powers. Phase factors, phase voltages, phase currents and line frequency are also measured, simultaneously. Based on the individual phase powers, total active power is determined.The power values are calculated over one-line frequency cycle. The negative and positive results are accumulated in different registers, which allows for separate billing of imported and exported active energy. Also, the reactive results are sorted depending on whether capacitive or inductive load is applied.

Eight pulse outputs are provided. Each billing quantity (+Wh, -Wh, +VArh, -Varh) is supplied with its own meter constant output, as well as a display counter output. In multi-channel mode, AT73C502 performs the functions of three independent single phase Wh meters and three impulse outputs are available, one for each meter element. All measurement information is available on an 8-bit microprocessor bus. The results are output in six packages, 16 bytes each. Mode and status information of the meter is also transferred with each data block.