BL0921

BL0921

BL0921

BL0921

http://www.belling.com.cn

- 5 -

3/15/2007

Total 13 Pages

Single Phase Energy Meter IC

Single Phase Energy Meter IC

Single Phase Energy Meter IC

Single Phase Energy Meter IC

with Integrated Oscillator

with Integrated Oscillator

with Integrated Oscillator

with Integrated Oscillator

TIMING CHARACTERISTIC

(VDD=5V, GND=0V, On-Chip Reference, Integrated Oscillator, Temperature range: -20~+70

°C)

Parameter

Value

Comments

t1

144ms

F1 and F2 pulse-width (Logic Low). When the power is low,

the t1 is equal to 144ms; when the power is high, and the

output period falls below 550ms, t1 equals to half of the

output period.

t2

F1 or F2 output pulse period.

t3

½ t2

Time between F1 falling edge and F2 falling edge.

t4

CF Pulse Period. See Transfer Function section.

t5

71ms

CF pulse-width (Logic high). When the power is low, the t5

is equal to 71ms; when the power is high, and the output

period falls below 180ms, t5 equals to half of the output

period.

t6

CLKIN/4

Minimum Time Between F1 and F2.

Notes:

1) CF is not synchronous to F1 or F2 frequency outputs.

2) Sample tested during initial release and after any redesign or process change that may affect this

parameter.

THEORY OF OPERATION

Principle of Energy Measure

In energy measure, the power information varying with time is calculated by a direct

multiplication of the voltage signal and the current signal. Assume that the current signal and the

voltage signal are cosine functions; V and I are the peak values of the voltage signal and the

current signal; ωis the angle frequency of the input signals; the phase difference between the

current signal and the voltage signal is expressed asФ. Then the power is given as follows:

)

cos(

)

cos(

)

(

Φ

+

×

=

wt

I

wt

V

t

p