MCP3909RD-3PH1 Microchip Technology, MCP3909RD-3PH1 Datasheet - Page 32

• Manufacturer Part Number: MCP3909RD-3PH1
• Description: REF DESIGN MCP3909 3PH ENGY MTR
• Manufacturer: Microchip Technology

Specifications of MCP3909RD-3PH1

• Main Purpose: Power Management, Energy/Power Meter
• Embedded: No
• Utilized Ic / Part: MCP3909, PIC18F2520, PIC18F4550
• Primary Attributes: 3-Ph, 220 VAC, In Case, LCD, USB, GUI
• Secondary Attributes: Opto-Isolated Interface for Safety
• Operating Voltage: 220 V
• Operating Current: 5 A
• Description/function: Energy Meter
• For Use With/related Products: MCP3909
• Lead Free Status / RoHS Status: Not applicable / Not applicable

MCP3909 3-Phase Energy Meter Reference Design
3.4.18
3.4.19
DS51643B-page 28
PHy_VAR (NOT IMPLEMENTED)
PERIOD
REGISTER 3-18:
This is the value for phase y reactive power. The goal is to get this value to equal X
VAR/LSB. This is done with the PHy_VAR_GLSB registers. When displaying the
reactive power for phase y, simply display the value in these registers with the decimal
point one digit in from the right, in milli-volt-amperes-reactive. (Note this decimal point
location, or LSB resolution of 0.1 mVAR, is specific for the 5(10)A, 220V rating that this
meter is designed for). This register is overwritten every LINE_CYC line cycles (written
only once if calibration is enabled).
NOT IMPLEMENTED IN THIS FIRMWARE/SOFTWARE RELEASE.
REGISTER 3-19:
This 32-bit register represents the total number of clock ticks that elapsed over the most
recent LINE_CYC line cycles. Each LSB represents 1.6 us with a 40 MHz clock on the
microcontroller. This register is overwritten every LINE_CYC line cycles (written only
once if calibration is enabled).
PERIOD
Name
PHA_VAR
PHB_VAR
PHC_VAR
Name
Bits
PHY_VAR REGISTERS
PERIOD REGISTER
32
Bits
32
32
32
Address
Address
0x0C0
0x0BA
0x0B2
0x0B6
Cof
Cof
R
R
R
R
© 2008 Microchip Technology Inc.