SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp/en/
+B
GND
S1
P
D
D
V
CC
S2
LowB
GND
For ErrAmp, Sanken SE series device recommended
For SI, Sanken linear regulator IC recommended
11
33
77
66
44
FB
ROCP
ErrAmp
55
Standby
ON/OFF
Standby
Out
CX
RX
SI
A
B
B
A
STR-W6756
Controller
(MIC)
S/GND
OCP/BD
SS/OLP
STR-W6756
Description
The STR-W6756 is a quasi-resonant topology IC designed for
SMPS applications. It shows lower EMI noise characteristics
than conventional PWM solutions, especially at greater than
2 MHz. It also provides a soft-switching mode to turn on the
internal MOSFET at close to zero voltage (V
DS
bottom point)
by use of the resonant characteristic of primary inductance
and a resonant capacitor.
The package is a fully molded TO-220, which contains the
controller chip (MIC) and MOSFET, enabling output power up
to 140 W with universal input or 240 W with a 230 VAC input.
The bottom-skip mode skips the first bottom of V
DS
and turns
on the MOSFET at the second bottom point, to minimize an
increase of operating frequency at light output load, improving
system-level efficiency over the entire load range.
There are two standby modes available to reduce the input power
under very light load conditions. The first is Auto-Standby
mode, which is internally triggered by periodic sensing, and
the other is a manual standby mode, which is executed by
clamping the secondary output. In general applications, the
manual standby mode reduces the input power further compared
to Auto-Standby mode.
The soft-start mode minimizes surge voltage and reduces
power stress to the MOSFET and to the secondary rectifying
Features and Benefits
▪
Quasi-resonant topology IC
Low EMI noise and soft
switching
▪
Bottom-skip mode
Improved system efficiency over
the entire output load by avoiding increase of switching
frequency
▪
Auto-Standby mode
Lowers input power at very light
output load condition
▪
Avalanche-guaranteed MOSFET
Improves system-level
reliability and does not require V
DSS
derating
▪
650 V / 0.73
Ω
▪
Various protections
Improved system-level reliability
Quasi-Resonant Topology
Primary Switching Regulators
Typical Application Diagram
Package: 6-pin TO-220
Not to scale
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