TLV431A, TLV431B, SCV431B

http://onsemi.com

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Figure 31. Isolated Output Line Powered Switching Power Supply

The above circuit shows the TLV431A/B 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

Controller

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

ALYWWG

G

PIN CONNECTIONS AND DEVICE MARKING

(Top View)

12 3

Cathode

Anode

2

3

(Top View)

XXX

= Specific Device Code

A

= Assembly Location

Y

= Year

L

= Wafer Lot

WW, 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)