CS5480 Three Channel Energy Measurement IC Features Description Superior Analog Performance with Ultra-low Noise Level & The CS5480 is a high-accuracy, three-channel, energy mea- High SNR surement analog front end. Energy Measurement Accuracy of 0.1% over 4000:1 th The CS5480 incorporates independent, 4 order, Delta-Sigma Dynamic Range analog-to-digital converters for every channel, reference cir- Current RMS Measurement Accuracy of 0.1% over 1000:1 cuitry, and the proven EXL signal processing core to provide Dynamic Range th active, reactive, and apparent energy measurement. In addi- 3 Independent 24-bit, 4 -order, Delta-Sigma Modulators for Voltage and Current Measurements tion, RMS and power factor calculations are available. 3 Configurable Digital Outputs for Energy Pulses, Calculations are output via configurable energy pulse, or direct Zero-crossing, or Energy Direction UART/SPI serial access to on-chip registers. Supports Shunt Resistor, CT, & 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 Three configurable digital outputs provide energy pulses, zero- - Instantaneous Voltage, Current, and Power crossing, energy direction, and interrupt functions. Interrupts Overcurrent, Voltage Sag, and Voltage Swell Detection can be generated for a variety of conditions including voltage Ultra-fast On-chip Digital Calibration sag or swell, overcurrent, and more. On-chip register integrity Internal Register Protection via Checksum and Write is assured via checksum and write protection. The CS5480 is Protection designed to interface to a variety of voltage and current sen- UART/SPI Serial Interface sors including shunt resistors, current transformers, and On-chip Temperature Sensor Rogowski coils. On-chip Voltage Reference (25ppm / C Typ.) Single 3.3V Power Supply On-chip functionality makes digital calibration simple and ul- Ultra-fine Phase Compensation tra-fast, minimizing the time required at the end of the Low Power Consumption: <13mW customer production line. Performance across temperature is Power Supply Configurations ensured with an on-chip voltage reference with very low drift. GNDA = GNDD = 0V, VDDA = +3.3V A single 3.3V power supply is required, and power consump- 4mm x 4mm, 24-pin QFN Package tion is very low at <13mW. To minimize space requirements, the CS5480 is offered in a low-cost, 4mm x 4mm 24-pin QFN ORDERING INFORMATION package. See Page 69. VDDA RESET VDDD CS5480 IIN1+ 4th Order Digital HPF PGA Modulator Filter IIN1- Option SSEL CS UART/SPI RX / SDI Serial IIN2+ 4th Order Digital HPF PGA Interface Modulator Filter Option TX / SDO IIN2- SCLK VIN+ 4th Order Digital HPF 10x Calculation Modulator Filter Option VIN- Energy DO1 To DO2 Pulse Conversion DO3 VREF+ Voltage Temperature Reference Sensor VREF- MODE System Clock Clock Generator GNDA XIN XOUT GNDD Cirrus Logic, Inc. Copyright Cirrus Logic, Inc. 2013 MAR13 CS5480 TABLE OF CONTENTS 1. Overview 5 2. Pin Description .6 2.1 Analog Pins 7 2.1.1 Voltage Input 7 2.1.2 Current1 and Current2 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 Digital Outputs 7 2.2.3 UART/SPI Serial Interface 7 2.2.3.1 SPI 8 2.2.3.2 UART 8 2.2.4 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 .18 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 19 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 19 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 Meter Configuration Modes .23 5.6 Tamper Detection and Correction 24 5.6.1 Anti-tampering on Current .24 5.6.1.1 Automatic Channel Selection 24 5.6.1.2 Manual Channel Selection .25 5.6.2 Anti-tampering on Voltage 25 5.7 Energy Pulse Generation .25 2 DS980F3