MCP3909-I/SS Microchip Technology, MCP3909-I/SS Datasheet - Page 33

• 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

6.0
The following application figures represent meter
designs using the MCP3909 device. Some of these
applications ideas are available as fully function meter
reference designs and demo boards. For complete
schematic and for fully function meter designs, visit
Microchip’s web page for demo board and reference
design availability.
.
FIGURE 6-1:
are used on MCP3909 Energy Meter Reference Design.
© 2009 Microchip Technology Inc.
CURRENT
VOLTAGE
MCP3909
ADC
ADC
APPLICATIONS INFORMATION
PIC Microcontroller
Power Calculations from Waveform sampling using PIC MCU. Register names shown
X2
X
F
PHA_V_RMS_OFF:16
X2
PHA_DELAY:8
S
PHA_I_RMS_OFF:16
PHA_W_OFF:32
S
S
6.1
Figure 6-1
waveform data based on a PIC MCU and MCP3909
device. The PIC MCU accomplishes the following
energy meter calculation outputs per phase, per line
cycle:
Output registers for the power quantities and
calibration registers for phase, offset, gain, and LSB
adjustment are available through a serial interface to
the PIC microcontroller. See Microchip’s web page for
firmware solution and demo board.
The example signal flow here shows 4 output power
quantities and 6 calibration registers. For a 60 Hz
design that is using 128 samples per line cycle for the
power calculation the MCP3909 would have a new
data
communication to gather 16-bits x 2 channels at
10 MHz is approximately 3.2 µs, leaving ~125 µs for
the power calculations before the next sample is ready.
PHA_W_GAIN:16
- RMS Current
- RMS Voltage
- Active Power
- Apparent Power
ready
X
Performing RMS, Apparent Power,
and Active Power using MCP3909
Waveform data
represents
pulse
X
PHA_VA_GAIN:16
every
power
MCP3909
X
130 µs.
calculations
DS22025B-page 33
RMS Current
Apparent Power
Active Power
RMS Voltage
The
from
SPI