Document Number: 002-08449 Rev *A

Page 2 of 46

MB39C502/503/504

Contents

1.

Typical Application ................................................................................................................................ 3

2.

Pin Configuration................................................................................................................................... 4

3.

Pin Configuration................................................................................................................................... 6

4.

Block Diagram........................................................................................................................................ 8

5.

Absolute Maximum Rating.................................................................................................................. 10

6.

Recommended Operating Conditions.................................................................................................11

7.

Electrical Characteristics .................................................................................................................... 13

8.

Protections and Power Good function............................................................................................... 22

8.1

Description......................................................................................................................................... 22

8.2

Timing Chart ...................................................................................................................................... 23

9.

Enhanced LPM Description ................................................................................................................ 27

9.1

Ultra Low Quiescent Current.............................................................................................................. 28

9.2

Extended On Time ............................................................................................................................. 28

9.3

Timing Chart of Enhanced LPM ......................................................................................................... 29

10.

Over Current Alerting Description.................................................................................................. 30

11.

Application Note .............................................................................................................................. 31

11.1

Setting Operating Conditions ............................................................................................................. 31

11.1.1

Setting Output Voltage ................................................................................................................... 31

11.1.2

Setting Over Current Limitation and Over Current Alerting ............................................................ 31

11.2

Selection Parts................................................................................................................................... 32

11.2.1

Selection of Smoothing Inductor .................................................................................................... 32

11.2.2

Selection of Switching FET ............................................................................................................ 33

11.2.3

Selection of Fly Back Diode ........................................................................................................... 35

11.2.4

Selection of Boost Diode................................................................................................................ 35

11.2.5

Selection of Input Capacitor ........................................................................................................... 36

11.2.6

Selection of Output Capacitor ........................................................................................................ 37

11.2.7

Selection of Boost Capacitor.......................................................................................................... 38

11.2.8

Selection of VDD Capacitor ........................................................................................................... 39

11.2.9

Selection of VCC Capacitor and Resistor ...................................................................................... 39

11.3

Layout ................................................................................................................................................ 40

12.

Ordering Information ....................................................................................................................... 43

13.

Package Dimensions ....................................................................................................................... 44

14.

Major Changes ................................................................................................................................. 45