DSPIC33FJ128GP706A-E/MR Microchip Technology, DSPIC33FJ128GP706A-E/MR Datasheet - Page 96

• Manufacturer Part Number: DSPIC33FJ128GP706A-E/MR
• Description: 16 Bit MCU/DSP 40MIPS 128KB FLASH 64 QFN 9x9x0.9mm TUBE
• Manufacturer: Microchip Technology
• Series: dsPIC™ 33Fr

Specifications of DSPIC33FJ128GP706A-E/MR

• Core Processor: dsPIC
• Core Size: 16-Bit
• Speed: 40 MIPs
• Connectivity: CAN, I²C, IrDA, LIN, SPI, UART/USART
• Peripherals: AC'97, Brown-out Detect/Reset, DMA, I²S, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 18x10b/12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 64-VFQFN, Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• 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
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