MCP3909-I/SS Microchip Technology, MCP3909-I/SS Datasheet - Page 36

• 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

MCP3909 / dsPIC33F 3-Phase Energy Meter Reference Design
DS51723A-page 36
3.5.1
The task of this module is to enable the MCP3909 device to enter the "Channel Output"
mode. This design uses the "Channel Output" mode of the MCP3909 device. In this mode,
the current and voltage data channels measured by the ADC is sent through the
MCP3909 device's SPI port. To enable the MCP3909 device to enter the Channel
Output mode, certain instructions must be sent to the device via the SPI interface within
a specified time (32CLK) after resetting the MCP3909 device.
• Enable all MCP3909 devices: enable ADCS1, ADCS2 and ADCS3, and configure
• Reset the MCP3909 device through the RESET pin. The pin must be pulled low
• After the RESET pin is pulled high, wait for 4 clock cycles for the MCP3909 device
• Send Instruction 0x94 to the MCP3909 device through the SPI Interface
• Configure the SPI interface to 16-bit mode and strobe the MCP3909 device for
FIGURE 3-6:
MCU's SPI to 8-bit mode
for no less than 1 clock cycle of the MCP3909 device
pin functions to reset
Phase A
Initialize and Configure MCP3909 Operation Mode
Initializing the MCP3909 Device Flow Chart.
Set SPI to 16-bit mode
the MCP3909 device
Wait for 4 CLK cycles
Send instruction 0xac
Strobe phase A of
MCP3909 devices
MCP3909 devices
Initialize MCP3909
Strobe all
Reset the
End
© 2009 Microchip Technology Inc.