SSC3S921

SSC3S921 - DSJ Rev.1.7

SANKEN ELECTRIC CO., LTD.

2

Jan. 17, 2018

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

© SANKEN ELECTRIC CO., LTD. 2015

Contents

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

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

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

2. Electrical Characteristics -------------------------------------------------------------------------------- 4

3. Block Diagram --------------------------------------------------------------------------------------------- 7

4. Pin Configuration Definitions--------------------------------------------------------------------------- 7

5. Typical Application --------------------------------------------------------------------------------------- 8

6. External Dimensions-------------------------------------------------------------------------------------- 9

7. Marking Diagram ----------------------------------------------------------------------------------------- 9

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

8.1

Resonant Circuit Operation --------------------------------------------------------------------- 10

8.2

Startup Operation--------------------------------------------------------------------------------- 13

8.3

Undervoltage Lockout (UVLO) ---------------------------------------------------------------- 14

8.4

Bias Assist Function------------------------------------------------------------------------------- 14

8.5

Soft Start Function -------------------------------------------------------------------------------- 14

8.6

Minimum and Maximum Switching Frequency Setting ----------------------------------- 15

8.7

High-side Driver ----------------------------------------------------------------------------------- 15

8.8

Constant Voltage Control Operation ---------------------------------------------------------- 15

8.9

Standby Function---------------------------------------------------------------------------------- 16

8.9.1

Standby Mode Changed by External Signal ------------------------------------------- 16

8.9.2

Burst Oscillation Operation --------------------------------------------------------------- 17

8.9.3

PFC ON/OFF Function -------------------------------------------------------------------- 17

8.10 Automatic Dead Time Adjustment Function ------------------------------------------------ 17

8.11 Brown-In and Brown-Out Function ----------------------------------------------------------- 18

8.12 Capacitive Mode Detection Function ---------------------------------------------------------- 19

8.13 Input Electrolytic Capacitor Discharge Function------------------------------------------- 20

8.14 Reset Detection Function ------------------------------------------------------------------------ 20

8.15 Overvoltage Protection (OVP) ------------------------------------------------------------------ 22

8.16 REG Overvoltage Protection (REG_OVP)--------------------------------------------------- 22

8.17 Overcurrent Protection (OCP) ----------------------------------------------------------------- 22

8.18 Overload Protection (OLP)---------------------------------------------------------------------- 23

8.19 Thermal Shutdown (TSD) ----------------------------------------------------------------------- 23

9. Design Notes ---------------------------------------------------------------------------------------------- 24

9.1

External Components ---------------------------------------------------------------------------- 24

9.1.1

Input and Output Electrolytic Capacitors---------------------------------------------- 24

9.1.2

Resonant Transformer --------------------------------------------------------------------- 24

9.1.3

Current Detection Resistor, ROCP -------------------------------------------------------- 24

9.1.4

Current Resonant Capacitor, Ci --------------------------------------------------------- 24

9.1.5

Gate Pin Peripheral Circuit --------------------------------------------------------------- 24

9.2

PCB Trace Layout and Component Placement --------------------------------------------- 24

10. Pattern Layout Example ------------------------------------------------------------------------------- 26

Important Notes---------------------------------------------------------------------------------------------- 28