LX1562IDM Microsemi Analog Mixed Signal Group, LX1562IDM Datasheet - Page 19

• 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
INDUCTOR DESIGN
Step 2: Choose a core with higher K
Step 3: Determine number of turns.
Step 4: Calculate air gap.
CURRENT SENSE RESISTOR
Current sense resistor, R6 is selected using the minimum multi-
plier output clamp voltage and the maximum inductor peak
current such that:
Power dissipation is approximated by:
Select THREE 1.3 , ¼W carbon comp resistors in parallel.
8/30
R6 =
P
P
R
R
Step 1.
K
where: k
K
K
N =
N =
A
choose #22 AWG with r = 0.0165 /feet resistance.
R
R
l
l
g
q
V
W
W
g
g
g
WIRE
/core = k
=
1
6
CLAMP(MIN)
1
6
=
I
factor for TDK PQ2625:
= 0.4
= N * l
L (MAX)
= 0.185
= k
B A
µ
4
I
(2.4)
L I
0.15 * 118 * 10
2 (MAX)
450 * 10
O
LP
*
N
A
A
l
A
A
l
(47.7) (118)
E
L
W
W
w
10
A
2
2
W
E
W
E
N
2
(continued)
=
W
* r
A
-7
(1 - 0.61) = 0.374
(1 - D'
= 47.7mm
= 118mm
= 56.2mm
A
56.2
E
450
*
-6
W
= 0.4
(61)
1.1
2.4
l
Winding coefficient (typ. k=0.4)
Bobbin window area
Effective core area
Mean length per turn
W
A
* 2.4
*
E
2
2
10
MIN
-6
*
2
= 0.45
47.7
118
-6
),
61
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
2
(mm)
2
= 61 turns
S
*
E C O N D
where D'
10
g
= 0.31mm
= 480mil
5
than the one calculated in
-6
= 4.7 * 10
P
A P P L I C AT I O N I N F O R M A T I O N
= 0.122cm = 48 mil
-G
R O D U C T I O N
MIN
2
E N E R AT I O N
2
= 1 -
-12
m
5
2 V
V
BOOST
AC(MIN)
P
O W E R
D
MULTIPLIER COMPONENT SELECTION
Calculate R1 & R2 resistor values such that under low line AC input
the multiplier output is lower than the minimum clamp voltage.
For K = 0.65 & V
Assuming R1 is selected to be:
* For high input applications such as 277V, R1 must be divided
into two resistors in series to meet the maximum rated voltage of
the resistors.
be connected from the supply voltage to this pin to allow an
increase in the switch on-time at the zero crossing by adding an
effective offset at the multiplier output.
ERROR AMPLIFIER COMPONENT SELECTION
Boost voltage is programmed with R7 & R8 resistor dividers using
the following equation:
assuming that the product of R7 and the E.A. input bias current
does not cause significant error in the output voltage setting.
Calculating R8:
Worst case output tolerance is the total of ±3.75% which is the sum
of ±1.5% (Ref), ±2% (resistor dividers), and ±0.25% (E.A. input
bias current).
A T A
F
To improve THD further (typ. 2-3%), a high value resistor can
A C T O R
* R1 = 2.2M (1%)
R2 =
Assuming R7 = 1M
R8 =
R1 + R2
R1
R2
R7
R8
V
ERROR
R2
where: K
S
> 83
2.2M
=
two resistors may be added in series to meet the voltage
requirement of the resistor.)
V
83
(10
C
V
BOOST
H E E T
REF
O N T R O L L E R
V
R7
* 2 V
6
V
BOOST
) (0.5 * 10
CLAMP (MIN)
REF
V
= 26.4k (1%)
- 1
EA)(MAX)
AC (MIN)
-1,
= 11k (1%)
= 1.1V, the ratio of R1/R2 is:
-6
(for output voltage of higher than 250V,
* K * (V
) = 0.5V,
Mult. Gain
Maximum error amp output where
multiplier is still in linear range.
This voltage is
LX1562/1563
EA0 (MAX)
select R
which is < 0.25% of the
output voltage.
- V
2
REF
3.5V.
= 26.7k (1%)
) < V
CLAMP (MIN)
19