CS5484 Four Channel Energy Measurement IC Features & Description Description Superior Analog Performance with Ultra-low Noise Level The CS5484 is a high-accuracy, four-channel, energy and High SNR measurement analog front end. Energy Measurement Accuracy of 0.1% over 4000:1 th The CS5484 incorporates independent 4 order Delta-Sigma Dynamic Range analog-to-digital converters for every channel, reference Current RMS Measurement Accuracy of 0.1% over 1000:1 Dynamic Range circuitry, and the proven EXL signal processing core to provide th 4 Independent 24-bit, 4 -order, Delta-Sigma Modulators active, reactive, and apparent energy measurement. In for Voltage and Current Measurements addition, RMS and power factor calculations are available. 4 Configurable Digital Outputs for Energy Pulses, Calculations are output through a configurable energy pulse, Zero-crossing, or Energy Direction or direct UART/SPI serial access to on-chip registers. Supports Shunt Resistor, CT, and Rogowski Coil Current Instantaneous current, voltage, and power measurements are Sensors also available over the serial port. Multiple serial options are On-chip Measurements/Calculations: offered to allow customer flexibility. The SPI provides higher - Active, Reactive, and Apparent Power speed, and the 2-wire UART minimizes the cost of isolation - RMS Voltage and Current where required. - Power Factor and Line Frequency - Instantaneous Voltage, Current, and Power Four configurable digital outputs provide energy pulses, Overcurrent, Voltage Sag, and Voltage Swell Detection zero-crossing, energy direction, and interrupt functions. Ultra-fast On-chip Digital Calibration Interrupts can be generated for a variety of conditions Internal Register Protection via Checksum and Write including voltage sag or swell, overcurrent, and more. On-chip Protection register integrity is assured via checksum and write protection. UART/SPI Serial Interface The CS5484 is designed to interface to a variety of voltage and On-chip Temperature Sensor current sensors including shunt resistors, current On-chip Voltage Reference (25ppm/C Typ.) transformers, and Rogowski coils. Single 3.3V Power Supply Ultra-fine Phase Compensation On-chip functionality makes digital calibration simple and Low Power Consumption: <13mW ultra-fast, minimizing the time required at the end of the Power Supply Configurations customer production line. Performance across temperature is - GNDA = GNDD = 0V, VDDA = +3.3V ensured with an on-chip voltage reference with low drift. A 5mmx5mm 28-pin QFN Package single 3.3V power supply is required, and power consumption is low at <13mW. To minimize space requirements, the ORDERING INFORMATION CS5484 is offered in a low-cost, 5mmx5mm 28-pin QFN See Page 68. package. VDDA RESET VDDD IIN1+ th 4 Order Digital CS5484 HPF PGA Modulator Filter Option IIN1- SSEL th IIN2+ 4 Order Digital HPF CS PGA UART/SPI Modulator IIN2- Filter Option RX / SDI Serial Interface TX / SDO th VIN1+ 4 Order Digital HPF SCLK 10x Modulator Filter Option VIN1- Calculation DO1 Configurable th M DO2 VIN2+ 4 Order Digital HPF Digital 10x U Modulator VIN2- X Filter Option DO3 Outputs DO4 Temperature System Clock VREF+ Voltage Sensor Clock Generator Reference MODE VREF- GNDA XIN XOUT CPUCLK GNDD Cirrus Logic, Inc. Copyright Cirrus Logic, Inc. 2013 MAR13 CS5484 TABLE OF CONTENTS 1. Overview 5 2. Pin Descriptions 6 2.1 Analog Pins 7 2.1.1 Voltage Inputs .7 2.1.2 Current Inputs .7 2.1.3 Voltage Reference .7 2.1.4 Crystal Oscillator .7 2.2 Digital Pins .7 2.2.1 Reset Input .7 2.2.2 CPU Clock Output 7 2.2.3 Digital Outputs 7 2.2.4 UART/SPI Serial Interface 8 2.2.5 SPI .8 2.2.6 UART .8 2.2.7 MODE Pin 8 3. Characteristics and Specifications .9 4. Signal Flow Description .17 4.1 Analog-to-Digital Converters 17 4.2 Decimation Filters 17 4.3 IIR Filters .17 4.4 Phase Compensation .17 4.5 DC Offset and Gain Correction 18 4.6 High-pass and Phase Matching Filters 18 4.7 Digital Integrators .18 4.8 Low-rate Calculations .18 4.8.1 Fixed Number of Samples Averaging 18 4.8.2 Line-cycle Synchronized Averaging .19 4.8.3 RMS Current and Voltage .19 4.8.4 Active Power .19 4.8.5 Reactive Power .19 4.8.6 Apparent Power 19 4.8.7 Peak Voltage and Current .19 4.8.8 Power Factor .19 4.9 Average Active Power Offset 20 4.10 Average Reactive Power Offset .20 5. Functional Description 21 5.1 Power-on Reset 21 5.2 Power Saving Modes 21 5.3 Zero-crossing Detection 21 5.4 Line Frequency Measurement .22 5.5 Energy Pulse Generation .22 5.5.1 Pulse Rate 24 5.5.2 Pulse Width 24 5.6 Voltage Sag, Voltage Swell, and Overcurrent Detection .24 2 DS981F3