Microchip Technology MA300015 Data Sheet
© 2008 Microchip Technology Inc.
DS01208A-page 7
AN1208
FIGURE 5:
STATE FLOW DIAGRAM OF DIGITAL PFC
Update
PWM2 Duty
Cycle
Current PI
Control
Calculate
Reference
Current
Voltage PI
Control
Power-on
delay
Calculate
∑ V
AC
and
Sample
Count 'N'
Calculate
Feed-forward
Compensate
En
d o
f P
ow
er-
on
D
ela
y
S
ta
rt
o
f P
o
w
e
r-
o
n
D
e
la
y
Measured V
AC
Measured V
DC
Calculate
Sample
Count 'N'
A/D Interrupt
Service
Routine
Measured I
AC
Wait for ADC
Interrupt
Measured V
AC
V
AVG
and
I
ACREF
Voltage
PFC Switch
Pressed
Read
I
A
and I
B
∑ V
AC
and