Cirrus Logic CRD5463PM User Manual
Actual Size:
120mm x 120mm x 60mm
AC Load
AC Line
Input/Switch
USB Port
CRD5463PM
CRD5463PM Power Monitor
Reference Design and Software
Features
Easy Plug-and-play Design
USB Communication with PC
Real-time Measurements:
– Line Voltage
– Load Current
–Active Power
–Reactive Power
– Apparent Power
– Power Factor
– Line Frequency
– Temperature
Operational Voltage: 90 ~ 260 VAC
Maximum Load Current: 15 A RMS
Active Power Measurement Accuracy:
– 0.2%, 3 ~ 3900 W
Lab Windows™/CVI™ GUI Software
Factory Calibrated, Re-calibration Capable
General Description
The CRD5463PM demonstrates the CS5463 power
measurement IC. It has an integrated AC-DC power supply,
voltage and current sensors, and isolated UART/USB
interface. Working with the GUI software, it provides accurate
real-time measurements of line voltage, load current, line
frequency, active power, reactive power, apparent power,
power factor, and temperature.
The CRD5463PM includes two power cords, a USB cable, and
a plug adaptor. When used with a PC, the CRD5463PM
immediately becomes a high-precision power meter. The
UART interface communication protocol, GUI, and MCU
software source codes are also available from Cirrus Logic.
The CRD5463PM is a useful design reference and evaluation
tool for customers to develop power metering/monitoring
systems that use the CS5463 IC.
ORDERING INFORMATION
CRD5463PM Power Monitor Reference Design
www.cirrus.com
Copyright Cirrus Logic, Inc. 2010
(All Rights Reserved)
OCT ‘10
DS805RD2
CRD5463PM
CRD5463PM
AC
SOURCE
AC
Load
GUI
USB
Reference
Meter
(V, A)
1. CHARACTERISTICS AND SPECIFICATIONS
1.1 Recommended Operating Conditions
Parameter Symbol Min Typ Max Unit
Voltage Range V
Current Range
RMS Current I
Peak Current I
Frequency Range Freq 5 2000 Hz
Operating Tempereture T
AC
rms
peak
A
1.2 Electrical Characteristics
Parameter Symbol Min Typ Max Unit
Power Consumption (Note 1)
Current Consumption
Power Consumption
Accuracy (Note 2)
RMS Voltage Measurement (90~ 260 VAC)
RMS Current Measurement (30 mA ~ 15 A)
Active Power Measurement (3 W ~ 3900 W)
Measurement Bandwidth BW - - 2 kHz
P
V
I
P
I
AC
AC
accu
accu
accu
90 - 260 V
--15A
--22A
-40 - +85 ºC
-79-mA
-2.3-W
-±0.1-%
-±0.2-%
-±0.2-%
NOTES:
1. Measured at VAC = 240 V and TA= 25º C.
2. Measured at T
= 25º C and PF=1.
A
WARNING
High Voltage Hazard
When the CRD5463PM is connected to AC lines, high voltage is present inside the box.
DO NOT REMOVE THE PROTECTIVE COVER FROM THE CRD5463PM WHEN POWER IS CONNECTED.
Figure 1. Calibration and Test Connection Diagram
NOTES:
1. Voltage drop and power loss in the cable connecting the CRD5463PM and the reference meter may introduce
additional error.
2. The measurement bandwidth of the CS5463 is 2 kHz. At low power factor, the CRD5463PM may measure lower
current and higher power factor than the reference meter if the reference meter has a measurement bandwidth
greater than 2 kHz.
3. When testing at low power factor, the peak load current shall never exceed 22 A.
2 DS805RD2
CRD5463PM
Voltage & Current
Sensors
CS5463
Power
Measurement
MCU
UART -
USB
SPI
Reset
Interrup t
UART
V
I
AC/DC
UART
Isolation
U
S
B
R
2
Vout
R
1
Vin
2RRR
VinVout
+
×=
mVrms
RR
R
Vin 176
2
max <
+
×
2. SYSTEM OVERVIEW
As illustrated in Figure 1, the CRD5463PM is composed of voltage and current sensors, a CS5463 power
measurement device, an ATtiny2313 microcontroller, opto-coupler isolation, and UART-USB converter.
Figure 2. CRD5463PM Simplified Block Diagram
2.1 DC Power Supplies
There are two isolated +5V DC power domains in the CRD. One is converted from AC power lines through
capacitor-dropper AC/DC power supply and provides +5VDC supply to the CS5463 and MCU. The other
is directly from PC through USB interface and provides +5VDC to the UART-USB converter.
This capacitor type of DC power supply is very low-cost but not efficient. Total power consumption drew
from the AC line is 2.3 Watt and 79mA (tested with 240 VAC input).
2.2 Voltage Sensor
The high AC line voltage must be converted to small voltage signal before being applied onto the CS5463
voltage channel inputs (VIN±). The CRD5463PM uses resistor voltage divider as the voltage sensor.
21
Figure 3. CRD5463PM Resistive Divider Voltage Sensor
The divider ratio is determined by the maximum Vin and the maximum input range of the CS5463 voltage
channel. The maximum input range of the CS5463 voltage channel is 176 mV RMS. The division ratio
shall be chosen to satisfy the equation:
21
To leave some margin, the Vout is normally set around 150 mVrms with the maximum V
CRD5463PM, R2 is 1 kΩ. R1 is composed of four 422 kΩ resistors to increase the total voltage rating of
the voltage sensor.
When V
DS805RD2 3
=260VRMS, V
in
= 260 V × 1 / [1 + (4 × 422)] = 154 mV RMS.
out
. In the
in
CRD5463PM
I
R
Shunt
Vout
RshuntIVout
mVpRshuntIpeak 50
2.3 Current Sensor
The AC load current must be converted into a low-level voltage signal before being applied to the CS5463.
A shunt resistor is a very common choice for current sensing in power monitoring applications because it
is inexpensive, small, linear, and normally doesn't introduce phase shift.
×=
Figure 4. CRD5463PM Shunt Resistor Current Sensor
Benefiting from its 50x gain amplifier and the low noise level on the current channel, the CS5463 can accommodate the ultra low-value shunt to achieve both low power dissipation at high current and high accuracy at low current.
The shunt resistance is determined by the maximum peak load current (I
) and the CS5463 current
peak
channel’s maximum input range. With the 50x PGA setting, the maximum input range of the CS5463’s
current channel is 50 mVp. Therefore, the Rshunt is chosen to satisfy the equation:
<×
The power rating of the shunt should be at least twice the actual power dissipation of the shunt with the
maximum continuous load current.
To measure the maximum of 15 A RMS and 23 A peak load current, the CRD5463PM uses a 2 mΩ, 1.5 W
shunt resistor as the current sensor.
2.4 CS5463 Power Measurement IC
The power measurement device CS5463 is on the daughter board. The CS5463 is an integrated power
measurement device which combines two ΔΣ analog-to-digital converter, power calculation engine and a
serial interface on a single chip. The sensed line voltage and load current are first converted into 24-bit
instantaneous values. The powerful on-chip DSP calculates voltage and current RMS values, active power, reactive power, apparent power, power factor, etc.
All these measurement values are available in specifically addressed 24-bit registers which can be accessed through SPI interface.
For more detailed information of the CS5463, please refer to the CS5463 datasheet.
http://www.cirrus.com/en/pubs/proDatasheet/CS5463_F2.pdf
4 DS805RD2
CRD5463PM
2.5 ATtiny2313 Microcontroller
In addition to the CS5463 on the daughter board, an Atmel™ ATtiny2313 microcontroller is used to initialize the CS5463, convert the SPI into UART, and provide nonvolatile memory for the calibrations.
The ATtiny2313 is an MCU with SPI and UART interfaces, 2 kB Flash program memory and 128 bytes
EEPROM data memory. The MCU acts as a communication bridge between the CS5463’s SPI interface
and the UART of the UART-to-USB converter. The EEPROM data memory is used to store calibration
information.
The hardware connections between the ATtiny2313 and the CS5463 are RESET
INT
(interrupt), and connection-configurable clock signals. Through the population of the 0 ohms resistor
R15 or R16, the clock source can be shared between the CS5463 and the ATtimy2313. In the current
version of the CRD5463PM, the CS5463 and ATtiny2313 are configured to use their own clock sources.
The CS5463 uses a 4.096 MHz crystal and the ATtiny2313 uses its internal 8 MHz R-C oscillator.
On the daughter board, connector J4 is provided for programming and debugging the ATtiny2313 MCU.
, SCLK, CS, SDI, SDO,
WARNING
High Voltage Hazard
The signal ground for the daughter board is the power line.
DO NOT CONNECT ANY DEBUGGING OR PROGRAMMING TOOLS TO THE J4 CONNECTOR WHEN
AC LINE POWER IS CONNECTED.
Please consult with Cirrus Logic engineering if re-programming the MCU is desired.
For more detailed information of ATtiny 2313, please refer to the ATtiny2313 datasheet.
2.6 Isolated UART
Because the CRD5463PM uses non-isolated components as the current and voltage sensors, the signal
ground of the CS5463 and MCU is the live connection to the main power. However, the signal ground of
the PC USB port is normally chassis ground or earth ground. The electrical isolation must be fulfilled on
the UART communication interface to allow the CRD5463PM to be connected to a PC through a USB
cable without short-circuit and safety problems. The CRD5463PM uses 2 opto-couplers to isolate the
UART interface. The isolation rating is 5300 V RMS.
2.7 UART-USB Interface- FT232R
A USB-to-UART interface IC, FT232R, is used on the main board to interface the CRD to a PC as a virtual
COM port through the USB connection.
3. SOFTWARE CONTROL
The CRD5463PM comes with GUI software and a USB cable to link the CRD to a PC. The GUI was developed with Lab Windows™/CVI™, a software development package from National Instrumen ts Corporation. The GUI software is available for download on the Cirrus Logic web site at:
http://www.cirrus.com/industrialsoftware
The software was designed to run under Windows 2000™ or Windows XP
DS805RD2 5
®
operating system.
CRD5463PM
4. INSTALLATION PROCEDURE
4.1 Software Installation Procedure
FTDI drivers must be installed before the GUI software is launched . Please refer to the following document
for details of how to install the drivers.
4.1.1 GUI Installation
1) Go to Cirrus Industrial Software download website (http://www.cirrus.com/industrialsoftware).
2) Click the link for the GUI desired.
3) Download the file onto the PC and unzip it. A new folder will be created.
4) Open the new folder and run the setup.exe file.
5) Follow the instructions presented by the installation wizard.
6) To Run the GUI, navigate to:
Start > All Programs >Cirrus Power Monitoring Reference (CRD5463PM) > CRD5463PM
4.1.2 Driver Installation
Important: FTDI drivers must be installed before the GUI software is launched . Please r efer to the f ollowing document for details of how to install the drivers.
http://www.ftdichip.com/Documents/AppNotes/AN_104_FTDI_Drivers_Installation_Guide_for_WindowsXP(FT_000093).pdf
4.2 Using the Software
Before launching the software, connect the CRD to an open USB port on the PC using the provided cable.
Connect the CRD to the main power and the load using provided power cord and plug adaptor. Once the
power has been switched on, the software program can be launched.
4.3 Main Window
When the software is launched, the Main window will appear. This window contains information concerning the software's title, revision number, copyright date, etc.
Figure 5. CRD5463PM GUI Main Window
At the top of the screen is a menu bar which displays user options. The menu bar has three items: System,
Connect, and Help.
6 DS805RD2
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