CS1601

14

DS931PP6

5.15 Summary of Equations

Eq. #

Equation

Variables/Recommended Values

1

Output Power (page 10)

Rated output power of the system.



Efficiency of the boost converter (estimated as

100% by the PFC algorithm).

measured after the rectifier and EMI filter.

Nominal PFC output voltage must be 400V.

Maximum switching frequency is 70kHz.

Boost inductor specified by rated power

requirement.



Margin factor to guarantee rated output power

Value of the IAC pin sense resistor(s).

Value of the IFB pin sense resistor(s).

Value of the fixed, internal reference current.

Value of the output capacitor in microfarads.

IC Supply Voltage.

OVP threshold.

Current into the IFB pin.

2

Output Power w/ recommended values (page 10)

3

Boost Inductor (page 10)

4

Output IFB Sense Resistor (page 11)

5

Input IAC Sense Resistor (page 11)

6

Auxiliary Winding Cut-off Frequency (page 12)

7

Maximum Response Time for Brownout: (page 12)

8

Overvoltage Protection

(page 12)

9

Boost Inductor Peak Current

10

Boost Inductor RMS Current

11









2





2





–







---------------------------------------------------------



=



90Vrms





2



400V

90Vrms

2





–

270kHz







-------------------------------------------------------------



=



90Vrms





2



400V

90Vrms

2





–

400V







-------------------------------------------------------------



=

–

-----------------------------

–

129

A

-------------------------------

==

=

12

 R3 R4



C

p





=

8ms

8ms

5V



–

 56 ms

++

=



+

=





 V



in min



2



--------------------------------------------

=









------------------------------

=

V

link rip



2

 f

line min









------------------------------------------------------------------------

=