SSC1S311A 查看數據表（PDF） - Sanken Electric co.,ltd.
零件编号
产品描述 (功能)
比赛名单
SSC1S311A Datasheet PDF : 28 Pages
| |||
SSC1S311A
Core Bobbin
Barrier tape
Core Bobbin
Barrier tape
P1 S1 P2 S2 D
P1 S1 D S2 S1 P2
Barrier tape
Barrier tape
Pin side
Pin side
Winding Structure Example (a)
Winding Structure Example (B)
P1, P2: Primary winding
S1: Secondary winding of which the output voltage is controlled constant
S2: Secondary winding
D: Auxiliary winding for VCC
Figure 8-6. Winding Structure Example
8.1.5. Soft-Start Function
Figure 8-7 shows the behavior of VCC pin voltage and
the drain current during the startup period.
The IC activates the soft-start function during the
startup period.
The soft-start operation period, tSS, is internally set to
6.05 ms, and the overcurrent protection (OCP) threshold
voltage steps up in four steps during this period. This
reduces the voltage and current stress on the power
MOSFET and on the secondary-side rectifier.
During the soft-start operation period, the operation is
in PWM operation with PWM operation frequency of
fOSC = 21.0 kHz.
In addition, because the soft-start operation period is
fixed internally, it is necessary to confirm and adjust the
VCC pin voltage and the overload protection (OLP) delay
time during startup, based on actual operation in the
application.
8.1.6. Operational Mode at Startup
As shown in Figure 8-8 because the auxiliary winding
voltage is low at startup, there is a certain period when
the quasi-resonant signal has not yet reached a regulated
level (Quasi-Resonant Operation Threshold Voltage 1,
VBD(TH1), is 0.24V or more, and the effective pulse width
for the quasi-resonant signal is 1.0μs or more). During
this period, the operation is in PWM operation with
PWM operation frequency of fOSC = 21.0 kHz. Then,
when the output voltage rises, the auxiliary winding
voltage will rise, and when a quasi-resonant signal
reaches the regulated level, quasi-resonant operation will
begin.
In addition, during the soft-start operation period, tSS,
the operation is in PWM operation, even if the quasi-
resonant signal reaches the regulated level.
Figure 8-7. Operational Mode in Startup
SSC1S311A-DSE Rev.1.3
SANKEN ELECTRIC CO., LTD.
11
Dec. 22, 2017
http://www.sanken-ele.co.jp/en
© SANKEN ELECTRIC CO., LTD. 2012
Share Link: 