TLV431, NCV431, SCV431
www.onsemi.com
13
Figure 31. Isolated Output Line Powered Switching Power Supply
The above circuit shows the TLV431A/B/C as a compensated amplifier controlling the feedback loop of an isolated output line
powered switching regulator. The output voltage is programmed to 3.3 V by the resistors values selected for R1 and R2. The
minimum output voltage that can be programmed with this circuit is 2.64 V, and is limited by the sum of the reference voltage
(1.24 V) and the forward drop of the optocoupler light emitting diode (1.4 V). Capacitor C1 provides loop compensation.
Gate Drive
V
CC
Controller
V
FB
GND
Current
Sense
DC Output
3.3 V
R1
3.0 k
R2
1.8 k
100
AC Input
C1
0.1 mF
Anode
Reference
NC
NC
Cathode
5
4
1
2
3
TLV43
1XXX
ALYWG
G
PIN CONNECTIONS AND DEVICE MARKING
(Top View)
123
Cathode
Anode
Reference
1
2
3
(Top View)
XXX = Specific Device Code
A = Assembly Location
Y = Year
L = Wafer Lot
W = Work Week
G = Pb−Free Package
(Note: Microdot may be in either location)
1. Reference
2. Anode
3. Cathode
TO−92 TSOP−5 SOT−23−3
XXX = Specific Device Code
M = Date Code
G = Pb−Free Package
(Note: Microdot may be in either location)
XXXMG
G
XXXAYWG
G
