MCP3909-I/SS Microchip Technology, MCP3909-I/SS Datasheet - Page 81

• 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

© 2009 Microchip Technology Inc.
Where:
EQUATION C-10:
Equation C-10 is called the quasi-synchronous window function. After determining the
sampling points, the number of iterations and numerical quadrature method, the
coefficients of quasi-synchronous window function will become definite, and a
quasi-synchronous window function arrays may be established in advance.
Using the quasi-synchronous window function to carry out the weighted process of the
original data is equivalent to carrying out data synchronization one time, and the
algorithm realization is also very simple that only a multiplication of the original data and
quasi-synchronous window function arrays is required. After processing, the new
periodic signal will have the same period and frequency components as the original
signal, and the synchronization error of the new signal becomes smaller.
Figure C-3 is a schematic of the quasi-synchronous window function characteristics in
the time domain and data processing. In Figure C-3, the red curve is the characteristic
of the window function, and the blue curve is input signal, and the green curve is the
output signal.
FIGURE C-3:
Processing.
Window function
Raw data
Data processed
Quasi-Synchronous Window Function Characteristics Curve and Data
Sampling point (1-193) Time 3.2 ksps
R
i
=
----- -
N
1
n
Power Calculation Theory
⋅
η
i
（
i = 0 ~ n x N
）
DS51723A-page 81