MCP3909RD-3PH3 Microchip Technology, MCP3909RD-3PH3 Datasheet - Page 20

• Manufacturer Part Number: MCP3909RD-3PH3
• Description: REF DESIGN FOR MCP3909 W/18F2520
• Manufacturer: Microchip Technology

Specifications of MCP3909RD-3PH3

• Main Purpose: Power Management, Energy/Power Meter
• Utilized Ic / Part: MCP3909, PIC18F2520, PIC18F4550
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

MCP3909 / dsPIC33F 3-Phase Energy Meter Reference Design
2.3
FIGURE 2-3:
DS51723A-page 20
SDO DR
ANALOG-TO-DIGITAL CONVERSION
Phase A,B,C I & V Data
3.3768 MHz (50 Hz Version)
This meter design uses Microchip's MCP3909 energy meter ICs. Small-signal current
inputs can be amplified by the programmable gain amplifier inside the MCP3909
device. The programmable range for the MCP3909's PGA is 16:1 V/V. The MCP3909
PGA gain can be configured by G0 and G1 (Pin 15 and 16 of the dsPIC33F).
The MCP3909 device's clock is provided by a 3.3768 MHz active crystal (for 50 Hz
system, see Appendix D. “50/60 Hz Meter Operation” for 60 Hz line frequency
information). The MCP3909 device's output data rate is 12.8 ksps. The clock lines and
MCLR lines of all 3 MCP3909 devices are connected together, which ensures that the
3 phases are strictly synchronous.
Clock Generation, Sampling Times and Calculation Frequencies.
x 6 ADCs
16 bits
t
MCP3909
LINE_CYC
f
f
f
SAMPLE3
SAMPLE1
SAMPLE2
t
SAMPLE
= 3.2 ksps (Harmonic Analysis, Distortion)
= 12.8 ksps (Active Power)
= 6.4 ksps (Reactive Power, RMS Current / Voltage)
X100
MCP3909
MCLK input
DR
MCP3909
DR Pulse
© 2009 Microchip Technology Inc.
(Input Capture)
To dsPIC33F
IRQ IC1