Cirrus Logic CS5484 - Manual

Copyright  Cirrus Logic, Inc. 2013
(All Rights Reserved)
Cirrus Logic, Inc.
http://www.cirrus.com
CS5484
Four Channel Energy Measurement IC
Features & Description
• Superior Analog Performance with Ultra-low Noise Level
and High SNR
• Energy Measurement Accuracy of 0.1% over 4000:1
Dynamic Range
• Current RMS Measurement Accuracy of 0.1% over 1000:1
Dynamic Range
• 4 Independent 24-bit, 4 th -order, Delta-Sigma Modulators
for Voltage and Current Measurements
• 4 Configurable Digital Outputs for Energy Pulses,
Zero-crossing, or Energy Direction
• Supports Shunt Resistor, CT, and Rogowski Coil Current
Sensors
• On-chip Measurements/Calculations:
- Active, Reactive, and Apparent Power
- RMS Voltage and Current
- Power Factor and Line Frequency
- Instantaneous Voltage, Current, and Power
• Overcurrent, Voltage Sag, and Voltage Swell Detection
• Ultra-fast On-chip Digital Calibration
• Internal Register Protection via Checksum and Write
Protection
• UART/SPI™ Serial Interface
• On-chip Temperature Sensor
• On-chip Voltage Reference (25ppm/°C Typ.)
• Single 3.3V Power Supply
• Ultra-fine Phase Compensation
• Low Power Consumption: <13mW
• Power Supply Configurations
- GNDA = GNDD = 0V, VDDA = +3.3V
• 5mmx5mm 28-pin QFN Package
ORDERING INFORMATION
See Page 68 .
Description
The CS5484 is a high-accuracy, four-channel, energy
measurement analog front end.
The CS5484 incorporates independent 4
th order Delta-Sigma
analog-to-digital converters for every channel, reference
circuitry, and the proven EXL signal processing core to provide
active, reactive, and apparent energy measurement. In
addition, RMS and power factor calculations are available.
Calculations are output through a configurable energy pulse,
or direct UART/SPI™ serial access to on-chip registers.
Instantaneous current, voltage, and power measurements are
also available over the serial port. Multiple serial options are
offered to allow customer flexibility. The SPI provides higher
speed, and the 2-wire UART minimizes the cost of isolation
where required.
Four configurable digital outputs provide energy pulses,
zero-crossing, energy direction, and interrupt functions.
Interrupts can be generated for a variety of conditions
including voltage sag or swell, overcurrent, and more. On-chip
register integrity is assured via checksum and write protection.
The CS5484 is designed to interface to a variety of voltage and
current sensors including shunt resistors, current
transformers, and Rogowski coils.
On-chip functionality makes digital calibration simple and
ultra-fast, minimizing the time required at the end of the
customer production line. Performance across temperature is
ensured with an on-chip voltage reference with low drift. A
single 3.3V power supply is required, and power consumption
is low at <13mW. To minimize space requirements, the
CS5484 is offered in a low-cost, 5mm x5mm 28-pin QFN
package.
VDDA
TX / SDO
RX / SDI
UART/SPI
Serial
Interface
Configurable
Digital
Outputs
RESET
Calculation
4 th Order 
Modulator
HPF
Option
DO1
DO2
HPF
Option
VREF+
VDDD
VREF-
System
Clock
IIN2+
IIN2-
PGA
IIN1+
IIN1-
PGA
10x
CS5484
CS
SCLK
SSEL
DO3
VIN1+
VIN1-
10x
VIN2+
VIN2-
Digital
Filter
Digital
Filter
DO4
MODE
HPF
Option
Digital
Filter
HPF
Option
Digital
Filter
M
U
X
4 th Order 
Modulator
4 th Order 
Modulator
4 th Order 
Modulator
GNDA GNDD
Voltage
Reference
Temperature
Sensor
XIN XOUT CPUCLK
Clock
Generator
MAR’13
DS981F3