PL3223– 3PH Multifunction Meter Measuring IC

Features

·      Compatible with 3 Phase/3 Wire, 3 phase/4 Wire and in Wye or Delta services

·      High Accuracy measurement – supports IEC 60687, IEC 61036, IEC 61268, IEC 62053-21 to 23

·      6 nos. 16 bit Second-order Σ-Δ ADC Current Channel inputs with built in PGA (4 programmable gains – 4,8,16 and 32)

·      Active Energy Error < 0.1% over dynamic range of 1000:1

·      Reactive Energy Error < 0.2% over dynamic range of 1000:1

·      Frequency measurement for each phase

·      Accurate Reactive Energy Measurement up to 21st harmonic

·      38 internal function register accessible through SPI

·      Active and Reactive Energy Calibration Pulse Output

·      Measures and supplies 2013 asme standardInstantaneous Active/ Reactive Energy, Line voltage, Current,

Frequency and RMS Voltage and Current information

·      Two Stepper motor output for direct driving of Active and Reactive Energy registers

·      interrupt generated for Low Voltage, Voltage Fail or Over-Voltage

·      Capable of implementing Digital phase correction and linear compensation for small current values

·      On-chip Digital temperature Sensor and digital compensation

·      Programmable Meter Constant

·      Programmable Starting Current

·      Easy and quick Microprocessor Interface through SPI

·      AD waveform data of real time voltage and current for all phases

·      Internal Voltage Reference

·      Single +5V supply operation

·      44 pin Industrial grade QFP packaging

 

FUNCTIONAL BLOCK DIAGRAM and PIN CONFIGURATION

20080715130103911

 

Description

The PL3223 is a high accuracy poly phase electrical energy measurement IC with a serial peripheral interface suitable for high-end multifunction metering application. It also has pulse outputs active and reactive enabling deployment of the same for low cost applications where only active or reactive energy mechanical registers are used for display.

PL3223 incorporates 6 nos. second order 16 bit Σ-Δ ADCs, reference circuitry, temperature sensor, and all the signal processing required to perform active, reactive energy measurements, and RMS calculations. It provides various API STD 1104 options for measuring active, and reactive energy from the six analog current channel inputs, thus making the chip compatible with various services like 3 Phase/3 Wire, 3 phase/4 Wire and in Wye or Delta services

In addition to RMS calculation, active and reactive power information, the chip also provides system calibration features digital calibration of parameters for each phase (i.e., channel offset correction, phase calibration, and gain calibration). Additionally it is also compatible with traditional resistor network calibration technique for low end applications. The PCF and QCF logic output provides instantaneous active and reactive power information for external use.

The PL3223 has a waveform sample register that enables access to ADC outputs. The chip also incorporates a detection circuit for short duration low or high voltage variations and also for voltage loss. The voltage threshold levels and the duration (number of half line cycles) of the variation are user programmable to avoid false alarms. In other words, an alarm is raised only when there is a out of bound voltage variation detection exceeding the threshold set in the number of half cycles.

A zero-crossing detection circuitry is synchronized with the zero-crossing point of the line voltage of each of the three phases. The information collected is used to measure each line’s period and in turn the frequency. It is also used internally to the chip in the line active energy and line reactive energy accumulation modes. This permits faster and more accurate calibration of the power calculations. This signal is also useful for synchronization in case relay switches are deployed in the circuitry.

PL3223 provides information of RMS value of current line voltage and line current by means of a simplified RMS value measurement unit. For the information of the users, PL3223 measurement unit does not calculate Root-Mean-Square value of voltage and current as understood conventionally. It provides value of the squares accumulated over a fixed period of time. We then have to read out this accumulated value, divide total number of samples and this would result in the RMS value of line voltage and line current.

Data is read from the chip via the SPI serial interface.  PL3223 has 38 internal function registers. Reading and writing operation of all these registers are executed through the built in Serial Peripheral Interface.  To ensure data integrity and security Internal registers are write protected upon power up of PL3223. This prevents any inadvertent modification of data or operation modes of the chip. If any operation mode or internal register data is to be edited, it is essential to disable the write protection of these registers. This prevents any unintentional, unauthorized or inadvertent changes on the internal registers.

The chip operates on a single +5V supply and available in 44 pin Quad Flat package (QFP) and all the internal proprietary modules are designed to withstand a wide variations in the environmental conditions and time. This chip offers a solution for designers to achieve a very low feature wise cost to build and reduced overall total system cost.