NE5562D Philipss, NE5562D Datasheet - Page 24

• Manufacturer Part Number: NE5562D
• Description: Switched-mode power supply control circuit
• Manufacturer: Philipss

Philips Semiconductors
1994 Aug 31
Switched-mode power supply control circuit
NOTE:
The P
1
Figure 42. Forward Converter Design Formulas
+
–
clamp winding prevents collector voltage from exceeding 2X V
To Prevent Core Saturation Due to
Flux Staircasing
max
Maximum Voltage Across Transistor
+
–
V
V
Figure 43. Isolated Secondary
CEmax
I
1
Demagnetization of Core
C
m
n
m
P
m
V
imax
n if m = n
Q
X
1
1
m
m
max
+
–
V
n
IN
D
C
1
< .5
O
(V)
C
P
V
O
+
–
Figure 41. Forward Converter
IN
P
2
during off time.
D
SL00430
SL00429
3
n
Q
1
P
1
n
24
S
1
Flyback Converter Design
Flyback Converter
Advantages:
Disadvantages:
Design Parameters for Flyback Inductor
Input
Output
Simple circuit. Only one inductive component even with line isola-
tion.
Economic. Low component count, low cost.
Work over large input voltage variations.
Can accommodate multiple outputs.
Large output ripple current due to discontinuous energy transfer.
Large output capacitor; has to supply part of the load current.
Low leakage inductance required to prevent high voltage spikes at
the switching transistors.
Relatively large core volume for the output power. Core driven in
one direction only.
Minimum input voltage
Maximum input voltage
Output voltage or voltages
Output current or currents
Output load
D
2
L
O
C
O
V
O
+
–
NE/SE5562
Product specification
SL00428