Cirrus Logic CS5490 - Manual

Copyright  Cirrus Logic, Inc. 2013
(All Rights Reserved)
Cirrus Logic, Inc.
http://www.cirrus.com
CS5490
Two Channel Energy Measurement IC
Features
• Superior Analog Performance with Ultra-low Noise Level &
High SNR
• Energy Measurement Accuracy of 0.1% over a 4000:1
Dynamic Range
• Two Independent 24-bit, 4 th -order, Delta-Sigma
Modulators for Voltage and Current Measurements
• Configurable Digital Output for Energy Pulses, Interrupt,
zero-crossing, and 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
• Configurable No-load Threshold for Anti-creep
• Internal Register Protection via Checksum and Write
Protection
• UART Serial Interface
• On-chip Temperature Sensor
• On-chip Voltage Reference (25ppm/°C Typ.)
• Single 3.3 V Power Supply
• Ultra-fine Phase Compensation
• Low Power Consumption: <13 mW
• Power Supply Configurations:
- GNDA = 0 V, VDDA: +3.3 V
• Low-cost 16-pin SOIC Package
Description
The CS5490 is a high-accuracy, two-channel, energy measure-
ment analog front end.
The CS5490 incorporates independent 4 th order Delta-Sigma an-
alog-to-digital converters for both channels, reference circuitry,
and the proven EXL signal processing core to provide active, re-
active, and apparent energy measurement. In addition, RMS and
power factor calculations are available. Calculations are output
via a configurable energy pulse, or direct UART serial access to
on-chip registers. Instantaneous current, voltage, and power
measurements are also available over the serial port. The
two-wire UART minimizes the cost of isolation where required.
A configurable digital output provides energy pulses, zero-cross-
ing, energy direction, or 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 CS5490 is designed to in-
terface 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 to minimize the time required at the end of the customer pro-
duction line. Performance across temperature is ensured with an
on-chip voltage reference with low drift. A single 3.3V power sup-
ply is required, and power consumption is low at <13mW. To
minimize space requirements, the CS5490 is offered in a low-cost
16-pin SOIC package.
ORDERING INFORMATION
See Page 57 .
VDDA
GNDA
RESET
Calculation
Temperature
Sensor
VREF+ Voltage
Reference
VDDD
VREF-
System
Clock
CS5490
MODE
Clock
Generator
XIN XOUT
TX
RX
UART
Serial
Interface
4th Order 
Modulator
Digital
Filter
HPF
Option
IIN+
IIN-
PGA
Digital
Filter
HPF
Option
10x
VIN+
VIN-
4th Order 
Modulator
DO
Configurable
Digital
Output
MAR’13
DS982F3