MCP3909EV-MCU16 Microchip Technology, MCP3909EV-MCU16 Datasheet - Page 96

• Manufacturer Part Number: MCP3909EV-MCU16
• Description: EVALUATION BOARD FOR MCP3909
• Manufacturer: Microchip Technology

Specifications of MCP3909EV-MCU16

• Number Of Adc's: 2
• Number Of Bits: 16
• Sampling Rate (per Second): 15k
• Data Interface: Serial
• Inputs Per Adc: 1 Differential
• Input Range: ±1 V
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: MCP3909
• Silicon Manufacturer: Microchip
• Application Sub Type: ADC
• Kit Application Type: Data Converter
• Silicon Core Number: MCP3909
• Kit Contents: Board
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

MCP3909 / dsPIC33F 3-Phase Energy Meter Reference Design
C.14 RELATIONSHIP BETWEEN ERROR AND CURRENT
DS51723A-page 96
For a given load and frequency, the absolute ratio error and angle error increase when
the primary current decreases from the rated value for un-compensated current trans-
former. The reason is that with the decrease of the secondary current, the magnetic
permeability µ of the iron core varies non-linearly, resulting in less reduction in the field
ampere turns.
Figure C-8 is a typical curve for load current and the phase lag of a CT. Generally,
phase lag of the output signal is great when the load current is small, and also
increases at a fast rate.
FIGURE C-8:
Current Load Versus CT Phase Lag.
Phase Lag
Current Load
© 2009 Microchip Technology Inc.