STR-W6753 Datasheet, PDF (1/8 Pages) Allegro MicroSystems – Universal-Input/58 W Off-Line Quasi-Resonant Flyback Switching Regulator

STR-W6753
Quasi-Resonant Topology
Primary Switching Regulators
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 / 1.70 Ω
▪ Various protections  Improved system-level reliability
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Package: 6-pin TO-220
Not to scale
Description
The STR-W6753 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 58 W with universal input or 120 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
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Typical Application Diagram
P
S1
+B
ErrAmp A
D
1
VCC
4
STR-W6753
Controller
(MIC)
6
FB
3
7
S/GND OCP/BD
5
RX
SS /OLP
CX
ROCP
D
S2
B SI
GND
Standby
ON/OFF
LowB
Standby
Out
GND
A For ErrAmp, Sanken SE series device recommended
B For SI, Sanken linear regulator IC recommended
28103.31
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp/en/