Rev. C 07/16

2

LYT7503-7504

www.power.com

Pin Functional Description

BYPASS (BP) Pin:

5.25 V supply rail.

MULTIFUNCTION (M) Pin:

Mode 1: MOSFET OFF

•

Detection of inductor de-magnetization (ZCD) to ensure CrM

•

Output OVP sensing (120 % of V

OUT nominal)

•

Steady-state operation voltage range is 1 V – 2.4 V

Mode 2: MOSFET ON

•

Line OVP

FEEDBACK (FB) Pin:

•

MOSFET current sensing using external current sense resistor

•

Normal operating range is V

FB(REF) to 0 V

DRAIN (D) Pin:

High-voltage internal MOSFET.

SOURCE (S) Pin:

Power and signal ground.

Figure 4. Pin Configuration.

Figure 3. Block Diagram.

PI-7907-071316

SOURCE

(S)

TON

STATE

MACHINE

UP/DN

COUNTER

BYPASS

(BP)

DRAIN

(D)

MULTI-

FUNCTION

(M)

FEEDBACK

(FB)

REGULATOR

5.25 V

IVALLEY

0.7 × VFB(REF)

4.5 V

0 V

IPK

R2

R1

IOVP

Line_Comp

OOVP

OTP

VOUT_SS

AC_Valley

AC_High

INPUT

LINE

SENSE

FAULT

HANDLING

ZERO

CURRENT

DETECTION

VOUT

SENSE

ILIMIT

SOA

THERMAL

SHUTDOWN

SYSTEM

CLOCK

S Q

R Q

FAULT

UV

CONTROL

LOGIC

PI-7908-032216

D Package (SO-8)

BP

M

FB

D

1

2

3

4

8

7

6

5

S

S

S

S