MCP3909-I/SS Microchip Technology, MCP3909-I/SS Datasheet - Page 11

• Manufacturer Part Number: MCP3909-I/SS
• Description: IC POWER METERING-1 PHASE 24SSOP
• Manufacturer: Microchip Technology

Specifications of MCP3909-I/SS

• Package / Case: 24-SSOP (0.200", 5.30mm Width)
• Input Impedance: 390 KOhm
• Measurement Error: 0.1%
• Voltage - I/o High: 2.4V
• Voltage - I/o Low: 0.85V
• Current - Supply: 2.3mA
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Meter Type: Single Phase
• Operating Temperature Range: - 40 C to + 85 C
• Mounting Style: SMD/SMT
• Supply Voltage Range: 4.5V To 5.5V
• Digital Ic Case Style: SSOP
• No. Of Pins: 24
• Interface Type: Serial, SPI
• Supply Voltage Max: 5.5V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: MCP3909EV-MCU16 - EVALUATION BOARD FOR MCP3909MCP3909RD-3PH1 - REF DESIGN MCP3909 3PH ENGY MTR
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

1.1
1.2
© 2009 Microchip Technology Inc.
INTRODUCTION
METER DESIGN PARAMETERS
The MCP3909 / dsPIC33F 3-Phase Energy Meter Reference Design is a fully
functional energy meter with many advanced features such as harmonic analysis, per
phase distortion information, voltage sag detection, four quadrant energy measure-
ment, and active and reactive power calculation. It uses Microchip’s powerful 16-bit
dsPIC33F Microcontroller Unit (MCU).
The MCP3909 / dsPIC33F 3-Phase Energy Meter Reference Design is unique in the
fact that all calculations take advantage of the dsPIC33F DSP engine, and all output
quantities are calculated in the frequency domain through the use of direct fourier
transforms (DFT). This approach yields a large volume of outputs for a variety of meter
designs, from simple active power only energy meters, to advanced energy meters
requiring harmonic analysis.
Another significant advantage of this design, is that the dsPIC firmware implements a
quasi-synchronous sampling algorithm, eliminating the need for external zero-crossing
detection and PLL (Phase Locked Loop) circuit for the synchronization of ADC samples
to line frequency. The line frequency is measured in software and corrected for mea-
surement errors caused by frequency fluctuations in the power grid. This additional
processing on the dsPIC reduces the overall meter cost by eliminating the requirement
for a PLL circuit.
• Accuracy Class: 0.2S
• Rated Current Ib: 3 X 5(20)A
• 3-phase 4-wire System
• Line Frequency Range: 47-53 Hz or 57-63 Hz
• ADC Sampling Rate: 12.8 ksps to 3.2 ksps
• Voltage Input:
• Starting Current: 0.001 I
• Active Power Measurement Range: 0-13200W, Precision Class: 0.2.
• Reactive Power Measurement Range: 0-13200VAR, Precision Class: 0.2.
• Power Factor (PF) Precision Class: 0.2.
• Frequency Measurement: Precision Class: 0.2, Max. Error 0.1 Hz
• Harmonic Component Measurement of Voltage Input: 2
• Harmonic Component Measurement of Current Input: 2
• Creeping: Anti-creeping Design (<0.0008 I
• Two Pulse Outputs: Total Phase Active Power, Total Phase Reactive Power
• Pulse Constant: 3200 Imp/kWh
(firmware option, see Appendix D. “50/60 Hz Meter Operation”)
- 3 x 220/380V
- 3 x 57.7/100V (3-Phase, 4-Wire)
Chapter 1. Meter Overview
ENERGY METER REFERENCE DESIGN
MCP3909 / DSPIC33F 3-PHASE
B
B
)
ND
ND
-31
-31
ST
ST
Harmonic
Harmonic
DS51723A-page 11