Cirrus Logic CS5461A - Manual

Copyright
 Cirrus Logic, Inc. 2011
(All Rights Reserved) http://www.cirrus.com
CS5461A
Single Phase, Bi-directional Power/Energy IC
Features
• Energy Data Linearity: ±0.1% of Reading over
1000:1 Dynamic Range
• On-chip Functions:
- Instantaneous Voltage, Current, and Power
- I
RMS
and V
RMS
, Apparent and Active (Real) Power
- Energy-to-pulse Conversion for Mechanical
Counter/Stepper Motor Drive
- System Calibrations and Phase Compensation
- Temperature Sensor
- Voltage Sag Detect
• Meets Accuracy Spec for IEC, ANSI, & JIS.
• Low Power Consumption
• Current Input Optimized for Sense Resistor.
• GND-referenced Signals with Single Supply
• On-chip 2.5 V Reference (25 ppm/°C typ)
• Power Supply Monitor
• Simple Three-wire Digital Serial Interface
• “Auto-boot” Mode from Serial E
2
PROM.
• Power Supply Configurations:
VA+ = +5 V; AGND = 0 V; VD+ = +3.3 V to +5 V
Description
The CS5461A is an integrated power measure-
ment device which combines two

analog-to-digital converters, power calculation
engine, energy-to-frequency converter, and a
serial interface on a single chip. It is designed to
accurately measure instantaneous current and
voltage, and calculate V
RMS
, I
RMS
, instanta-
neous power, apparent power, and active power
for single-phase, 2- or 3-wire power metering
applications.
The CS5461A is optimized to interface to shunt
resistors or current transformers for current mea-
surement, and to resistive dividers or potential
transformers for voltage measurement.
The CS5461A features a bi-directional serial in-
terface for communication with a processor, and
a programmable energy-to-pulse output func-
tion. Additional features include on-chip
functionality to facilitate system-level calibration,
temperature sensor, voltage sag detection, and
phase compensation.
ORDERING INFORMATION:
See Page 43.
VA+ VD+
IIN+
IIN-
VIN+
VIN-
VREFIN
VREFOUT
AGND XIN XOUT CPUCLK DGND
CS
SDO
SDI
SCLK
INT
Voltage
Reference
System
Clock
/K
Clock
Generator
Serial
Interface
E-to-F
Power
Monitor
PFMON
x1
RESET
Digital
Filter
Calibration
MODE
Power
Calculation
Engine
4th Order 
Modulator
2nd Order 
Modulator
Temperature
Sensor
Digital
Filter
PGA
HPF
Option
HPF
Option
E1
E2
E3
x10
APR ‘11
DS661F3