SA9122E Datasheet, PDF (9/12 Pages) Sames – SINGLE PHASE UNIDIRECTIONAL POWER/ENERGY METERING IC WITH SEPERATE 64 SEGMENT LCD DRIVER

SA9122E
The formula for calculating the output frequency is given below:
f = 11.16
*
FOUTX
FOSC
* _3.58MHz
*
I_I .I_V
I²
R
Where FOUTX = Normal rated frequency (4Hz or 1160Hz)
FOSC = Oscillator frequency (2MHz ...... 4MHz)
I_I
= Input current for current sensor input (16µA at rated line current)
I
= Input current for voltage sensor input (14µA at rated line voltage)
V
I_R
= Reference current (typically 50µA)
XTAL is a colour burst TV crystal (f = 3.5795 MHz) for the oscillator. The oscillator
frequency is divided down to 1.7897 MHz on-chip, to supply the digital circuitry and the
A/D converters.
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