Rev. A 06/10

2

LNK454/456-458/460

www.powerint.com

This document contains information on a new product. Specifications and information herein

are subject to change without notice.

PRELIMINARY

Figure 3.

Pin Configuration (Top View).

Figure 2.

Functional Block Diagram.

Pin Functional Description

DRAIN (D) Pin:

High-voltage power MOSFET drain connection. The internal

start-up bias current is drawn from this pin through a switched

high-voltage current source. Drain current sensing and

associated controller functions are also performed using this pin.

SOURCE (S) Pin:

Power MOSFET source connection. Ground reference for

BYPASS and FEEDBACK pins.

BYPASS (BP) Pin:

Connection point for the external bypass capacitor for the

internally generated 5.85 V supply.

FEEDBACK (FB) Pin:

LED current sensing pin. During normal operation the 290 mV

threshold determines the average value of the current flowing

through the load sense resistor.

A second higher threshold clamps excessive output current ripple.

An additional higher threshold is used to protect against output

short-circuit and overvoltage conditions.

PI-5893-060210

DRAIN (D)

SOURCE (S)

BYPASS (BP)

FEEDBACK (FB)

Zero Crossing

4.9 V

UV

SOA

UV

Update

CLK

S

Q

R

Q

S

Q

R

Q

ON-TIME

EXTENSION

AUTO-RESTART

VARIABLE FREQUENCY/

DUTY CONTROLLER

DIGITAL

INTEGRATOR

INC/DEC

FILTER

PHASE

MEASUREMENT

REGULATOR

5.85 V

SET

CLR

SET

CLR

+

+

+

+

+

CURRENT LIMIT

SOA

STATE MACHINE

1

µA

PI-5836a-0526–10

Exposed Pad Internally

Connected to SOURCE Pin

1 NC

2 FB

3 BP

4 NC

5 NC

6 D

S 12

S 11

S 10

S 9

S 8

S 7

V Package (eDIP-12)

D Package (SO-8C)

FB

BP

D

1

2

4

8

7

6

5

S

S

S

S