LLC Current-Resonant Off-Line Switching Controller
SSC3S921
Data Sheet
Description
Package
The SSC3S921 is a controller with SMZ* method for
LLC current resonant switching power supplies,
incorporating a floating drive circuit for a high-side
power MOSFET. The IC includes useful functions such
as Standby Function, Automatic Dead Time Adjustment,
and Capacitive Mode Detection.
SOP18
The IC achieves high efficiency, low noise and high
cost-performance power supply systems with few
external components.
*SMZ: Soft-switched Multi-resonant Zero Current
switch, achieved soft switching operation during all
switching periods.
Not to scale
Features
● Standby Mode Change Function
▫ Output Power at Light Load: PO = 125 mW
(PIN = 0.27 W, as a reference with discharge resistor
of 1MΩ for across the line capacitor)
▫ Burst operation in standby mode
▫ Soft-on/Soft-off function: reduces audible noise
● PFC IC ON/OFF Function: In standby operation, the IC
turns off PFC IC.
Applications
Switching power supplies for electronic devices such as:
● Digital appliances: LCD television and so forth
● Office automation (OA) equipment: server, multi-
function printer, and so forth
● Soft-start Function
● Capacitive Mode Detection Function
● Reset Detection Function
● Industrial apparatus
● Communication facilities
● Automatic Dead Time Adjustment Function
● Input Electrolytic Capacitor Discharge Function
● Protections
▫ Brown-In and Brown-Out Function:
▫ High-side Driver UVLO: Auto-restart: Auto-restart
▫ Overcurrent Protection (OCP): Auto-restart, peak
drain current detection, 2-step detection
▫ Overload Protection (OLP): Auto-restart
▫ Overvoltage Protection (OVP): Auto-restart
▫ REG Overvoltage Protection (REG_OVP): Latched
shutdown
▫ Thermal Shutdown (TSD): Auto-restart
Typical Application
VOUT1(+)
PFC OUT
U1
VSEN
VCC
FB
ST
1
2
3
4
5
6
7
8
9
18
17
16
15
14
13
12
11
10
GND
VGH
VS
ADJ
CSS
CL
VOUT(-)
VB
RC
REG
VGL
GND
VOUT2(+)
PL
SB
PFC IC
(SSC2016S)
VCC
TC_SSC3S921_1_R4
SSC3S921 - DSJ Rev.1.92
Oct. 03, 2023
SANKEN ELECTRIC CO., LTD.
https://www.sanken-ele.co.jp/en/
1
© SANKEN ELECTRIC CO., LTD. 2015