[AP3603]

015000004-E-02

2015/07

- 2 -

3.

Table of Contents

1.

General Description ........................................................................................................................................... 1

2.

Features.............................................................................................................................................................. 1

3.

Table of Contents............................................................................................................................................... 2

4.

Block Diagram................................................................................................................................................... 3

5.

Ordering Guide .................................................................................................................................................. 3

6.

Pin Configurations and Functions...................................................................................................................... 4

■ Pin Configurations....................................................................................................................................... 4

■ Functions ..................................................................................................................................................... 5

7.

Absolute Maximum Ratings .............................................................................................................................. 6

8.

Recommended Operating Conditions ................................................................................................................ 6

9.

Electrical Characteristics ................................................................................................................................... 7

10. Functional Descriptions ..................................................................................................................................... 8

10.1

Basic Operation ..................................................................................................................................... 8

10.2

Shut Down ............................................................................................................................................. 8

10.3

Power On Sequence............................................................................................................................... 8

10.4

Soft Start ................................................................................................................................................ 8

10.5

Power Down Sequence .......................................................................................................................... 8

10.6

Over Voltage Protection ........................................................................................................................ 8

10.7

Quasi-Foldback Over Current Protection (PWM operation) ................................................................. 8

10.8

CC1 and CC2 Pin Voltage (Error Amplifier output) Clamping Function ............................................. 9

10.9

External Synchronous Operation ........................................................................................................... 9

11. Timing Chart.................................................................................................................................................... 10

12. Application Information .................................................................................................................................. 11

12.1

Output Voltage Setting ........................................................................................................................ 11

12.2

Operational Frequency Setting ............................................................................................................ 11

12.3

Maximum ON Duty Setting................................................................................................................. 11

12.4

Maximum Output Voltage ................................................................................................................... 11

13. Attention of PCB Layout ................................................................................................................................. 12

■ Recommended Layout ............................................................................................................................... 12

■ GND Layout .............................................................................................................................................. 12

■ Switching Node Layout ............................................................................................................................. 12

■ Current Sense Resistor Layout .................................................................................................................. 12

■ Feedback Pin Layout ................................................................................................................................. 12

■ Capacitors for V8, V4 and SS.................................................................................................................... 12

■ Bypass Capacitor ....................................................................................................................................... 12

14. Typical Characteristics .................................................................................................................................... 13

15. Recommended External circuits ...................................................................................................................... 14

■

Recommended External Circuit of Dual Output.................................................................................. 14

■

Parts List .............................................................................................................................................. 14

■

Recommended External Circuit of Dual Phase Single Output ............................................................ 15

■

Parts List .............................................................................................................................................. 15

16. Package............................................................................................................................................................ 16

■ Outline Dimensions ................................................................................................................................... 16

■ Marking ..................................................................................................................................................... 16

17. Revise History ................................................................................................................................................. 17

Add 10.7 Quasi-Foldback Over Current Protection (PWM operation) ........................................................... 17

IMPORTANT NOTICE .......................................................................................................................................... 18