AN-32
+
+
VO
-
VAC
470 Ω (VO = 12 V)
100 Ω (VO = 5 V)
CIRCUIT PERFORMANCE
Circuit Tolerance ±1%
Load Regulation ±0.2%
Line Regulation ±0.2%
CIN
UTV817A
TOPSwitch-GX
1 kΩ
D
S
L
CONTROL
C
VO - 2.5
R =
X10 kΩ
100 nF
2.5
3.3 kΩ
X
F
TL431
10 kΩ
Feedback Circuit
PI-3329-112202
Figure 6. Opto/TL431 Feedback Circuit.
Step 3. Determine minimum and maximum DC input
voltagesVMIN,VMAX andinputstoragecapacitanceCIN based
on AC input voltage and PO (Figure 7)
P/N
CTR(%) BVCEO Manufacturer
4 Pin DIP
PC123Y6
PC817X1
SFH615A-2
SFH617A-2
SFH618A-2
ISP817A
LTV817A
LTV816A
LTV123A
K1010A
6 Pin DIP
LTV702FB
LTV703FB
LTV713FA
K2010
80-160 70 V Sharp
80-160 70 V Sharp
• Choose input storage capacitor, CIN per Table 4.
63-125 70 V Vishay, Isocom
63-125 70 V Vishay, Isocom
63-125 55 V Vishay, Isocom
80-160 35 V Vishay, Isocom
80-160 35 V Liteon
80-160 80 V Liteon
80-160 70 V Liteon
60-160 60 V Cosmo
Input (VAC)
Universal
CIN (µF/Watt of PO) VMIN (V)
2 ~ 3
1
≥ 90
230 or 115 with doubler
Table 4
≥ 240
63-125 70 V Liteon
63-125 70 V Liteon
80-160 35 V Liteon
60-160 60 V Cosmo
• Set bridge rectifier conduction time, tC = 3 ms.
• Derive minimum DC input voltage VMIN
PC702V2NSZX 63-125 70 V Sharp
PC703V2NSZX 63-125 70 V Sharp
PC713V1NSZX 80-160 35 V Sharp
PC714V1NSZX 80-160 35 V Sharp
1
2 × P ×
− t
C
O
2 × f
VMIN = (2 × VA2CMIN ) −
L
η × CIN
MOC8102
MOC8103
MOC8105
CNY17F-2
73-117 30 V Vishay, Isocom
where units are volts, watts, Hz, seconds and farads
108-173 30 V Vishay, Isocom
63-133 30 V Vishay, Isocom
63-125 70 V Vishay, Isocom,
Liteon
• Calculate maximum DC input voltage VMAX
:
VMAX = 2 × VACMAX
Table 3. Optocoupler
B
12/02
7
ETC [ ETC ]
