STR5A460 Series

STR5A460-DSE Rev.3.5

SANKEN ELECTRIC CO., LTD.

2

Aug. 21, 2018

https://www.sanken-ele.co.jp/en

© SANKEN ELECTRIC CO., LTD. 2013

Contents

Description ------------------------------------------------------------------------------------------------------ 1

Contents --------------------------------------------------------------------------------------------------------- 2

1. Absolute Maximum Ratings----------------------------------------------------------------------------- 3

2. Electrical Characteristics -------------------------------------------------------------------------------- 3

3. Performance Curves -------------------------------------------------------------------------------------- 5

4. Block Diagram --------------------------------------------------------------------------------------------- 6

5. Pin Configuration Definitions--------------------------------------------------------------------------- 6

6. Typical Application --------------------------------------------------------------------------------------- 7

7. Physical Dimensions and Marking Diagrams-------------------------------------------------------- 8

7.1

DIP8---------------------------------------------------------------------------------------------------- 8

7.2

SOIC8-------------------------------------------------------------------------------------------------- 9

8. Operational Description ------------------------------------------------------------------------------- 10

8.1

Startup Operation of IC ------------------------------------------------------------------------- 10

8.2

Undervoltage Lockout (UVLO) ---------------------------------------------------------------- 10

8.3

Power Supply Startup and Soft Start Function --------------------------------------------- 10

8.4

Constant Voltage (CV) Control----------------------------------------------------------------- 11

8.4.1

Buck Converter Operation ---------------------------------------------------------------- 12

8.4.2

Inverting Converter Operation ----------------------------------------------------------- 12

8.5

Leading Edge Blanking Function -------------------------------------------------------------- 13

8.6

Random Switching Function -------------------------------------------------------------------- 13

8.7

Operation Mode ----------------------------------------------------------------------------------- 13

8.8

Overload Protection (OLP)---------------------------------------------------------------------- 14

8.9

Overvoltage Protection (OVP) ------------------------------------------------------------------ 14

8.10 Thermal Shutdown (TSD) ----------------------------------------------------------------------- 14

9. Design Notes ---------------------------------------------------------------------------------------------- 15

9.1

External Components ---------------------------------------------------------------------------- 15

9.1.1

Input and Output Electrolytic Capacitor ----------------------------------------------- 15

9.1.2

Inductor --------------------------------------------------------------------------------------- 15

9.1.3

VCC Pin Peripheral Circuit--------------------------------------------------------------- 15

9.1.4

FB Pin Peripheral Circuit ----------------------------------------------------------------- 15

9.1.5

Freewheeling diode-------------------------------------------------------------------------- 16

9.1.6

Bleeder resistance --------------------------------------------------------------------------- 16

9.2

D/ST Pin--------------------------------------------------------------------------------------------- 16

9.3

Inductance Calculation--------------------------------------------------------------------------- 17

9.3.1

Parameter Definition ----------------------------------------------------------------------- 17

9.3.2

Buck Convertor ------------------------------------------------------------------------------ 18

9.3.3

Inverting Convertor ------------------------------------------------------------------------ 22

9.4

PCB Trace Layout -------------------------------------------------------------------------------- 26

10. Pattern Layout Example ------------------------------------------------------------------------------- 28

10.1 Buck Converter ------------------------------------------------------------------------------------ 28

10.2 Inverting Converter------------------------------------------------------------------------------- 29

11. Reference Design of Power Supply ------------------------------------------------------------------ 30

11.1 Buck Converter ------------------------------------------------------------------------------------ 30

11.2 Inverting Converter------------------------------------------------------------------------------- 31

Important Notes---------------------------------------------------------------------------------------------- 32