LX1562IDM Microsemi Analog Mixed Signal Group, LX1562IDM Datasheet - Page 21

• Manufacturer Part Number: LX1562IDM
• Description: IC CONTROLLER PFC 13.1V 8SOIC
• Manufacturer: Microsemi Analog Mixed Signal Group

Specifications of LX1562IDM

• Mode: Discontinuous Conduction (DCM)
• Frequency - Switching: 1.7MHz
• Current - Startup: 200µA
• Voltage - Supply: 11 V ~ 25 V
• Operating Temperature: 0°C ~ 100°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Copyright © 1996
Rev. 1.3a
POWER MOSFET SELECTION
The voltage rating of MOSFET and rectifier must be higher than
the maximum value of the output voltage.
The RMS current can be approximated by multiplying the RMS
current at the peak of the line by 0.7.
INPUT RECTIFIER AND CAPACITOR SELECTION
The current through each diode is a half-wave rectified sine wave.
The maximum current happens at minimum line with a peak
value of 1.2A.
V
I
I
IRF730 with R
requirements.
I
choose 1N4004 with 1A rating.
P
T
T
8/30
RMS
RMS
AVE
DISS
J
J
DS
= T
= 80 + (.344)(65) = 102°C
D = 0.39 at V
I
R
P
R
= 0.7 I
=
= (0.7)(2.4)( .39/3) = 0.61A
LP
DS
DC
DS
= (I
1.2 V
A
= 2.4A
I
+ P
PEAK
AVE
allowable power
dissipation.
0.61
LP
I
) (V
D
P
O MAX
RMS
1
DC
x
=
D/3
2
F
DS
) = 0.38 x 0.9 = 0.344W
= 1.6
JA
AC
= 1 and V
1.2
= 100V
= 0.38A
assuming
lead length.
V
D
DS
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
On-time duty cycle
DS
S
282V
E C O N D
= 400V meets the above
JA
I
= 65°C/W for 1/8"
P
RMS
A P P L I C AT I O N I N F O R M A T I O N
-G
R O D U C T I O N
/triangle = I
I
LP
D
E N E R AT I O N
LP
D/3
P
O W E R
D
Assuming
C1 can be calculated using the following equations:
if
OUTPUT CAPACITOR SELECTION
There are mainly two criteria for selecting the output capacitor:
A large enough capacitance to maintain a low ripple voltage, and
a low ESR value in order to prevent high power dissipation due
to RMS currents.
The output capacitance can be approximated from the following
equation:
A T A
F
R
C1
R
C1
choose 1µF, 250V capacitor.
A C T O R
= 3%
C6
I
assuming 5% peak to peak ripple,
C6
choose C6 = 100µF.
EFF
EFF
DC
=
=
=
(.03)(2 )(117)(50000)
S
(.95)(1.2)
2 P
2 (60) (11.5)
2 f
230
2 x 80
2 R
C
is the percentage of allowable input current ripple,
80
H E E T
I
P
O N T R O L L E R
O
2
LINE
I
0.348
1
DC
EFF
= 0.348A
2
f
1
V
SW
= 117
= 81µF
where: I
f
= 0.9µF
SW
LX1562/1563
DV
DC
Switching frequency
of inductor current
at peak input voltage.
DC output current
Output ripple
21