Sanken STR-W6756 User manual

SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp/en/
+B
GND
S1
P
D
DV
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 (VDS 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 VDS 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 VDSS 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
Continued on the next page…
Continued on the next page…
28103.33

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SANKEN ELECTRIC CO., LTD.
28103.33
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6756
diodes during the start-up sequence. Various protections such as
overvoltage, overload, overcurrent, maximum on-time protections
and avalanche-energy-guaranteed MOSFET secure good system-
level reliability.
Applications include the following:
▪Set Top Box
▪LCD PC monitor, LCD TV
▪Printer, Scanner
▪SMPS power supplies
Selection Guide
Part Number Package
STR-W6756 TO-220
Features and Benefits (continued) Description (continued)
All performance characteristics given are typical values for circuit or
system baseline design only and are at the nominal operating voltage and
an ambient temperature, TA, of 25°C, unless otherwise stated.
▫Pulse-by-pulse drain overcurrent limiting
▫Overvoltage protection (bias winding voltage sensing),
with latch
▫Overload protection with latch
▫Maximum on-time limit
Absolute Maximum Ratings at TA= 25°C
Parameter Symbol Conditions Rating Unit
Drain Current1IDpeak Single pulse 15 A
Maximum Switching Current2IDmax TA= –20°C to 125°C 15 A
Single Pulse Avalanche Energy3EAS Single pulse, VDD = 99 V, L = 20 mH, ILpeak = 6.05 A 400 mJ
Input Voltage for Controller (MIC) VCC 35 V
SS/OLP Terminal Voltage VSSOLP –0.5 to 6.0 V
FB Terminal Inflow Current IFB 10 mA
FB Terminal Voltage VFB IFB within the limits of IFB –0.5 to 9.0 V
OCP/BD Terminal Voltage VOCPBD –1.5 to 5.0 V
MOSFET Power Dissipation4PD1
With infinite heatsink 29 W
Without heatsink 1.3 W
Controller (MIC) Power Dissipation PD2 VCC × ICC 0.8 W
Operating Internal Leadframe Temperature TFRecommended operation temperature, see cautions –20 to 115 °C
Operating Ambient Temperature TOP –20 to 115 °C
Storage Temperature Tstg –40 to 125 °C
Channel Temperature Tch 150 °C
1Refer to figure 2
2IDMAX is the drain current determined by the drive voltage of the IC and the threshold voltage, Vth, of the MOSFET
3Refer to figure 3
4Refer to figure 5

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SANKEN ELECTRIC CO., LTD.
28103.33
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6756
D
S/GND
OCP/BD
V
CC
FB
R
S
Q
Reg and
I
const
OVP
Drive Control IC
Reg
Protection
Latch
S
RQ
FB
OCP
BSD
BD
Bottom Select
Counter
SS/OLP
OLP
Delay
S
R
Q
OSC
Max On
Soft Start
Burst
Control
Start
Stop
Burst
Control
4
+
-
+
-
+
-
+
-
+
-
+
-
1
3
6
7
5
Temperature, T
F
(°C)
Safe Operating Area
Temperature Derating Coefficient (%)
0
20
40
60
80
100
0 20 40 60 10080 120
Drain-to-Source Voltage, VDS (V)
Drain Current, ID(A)
10.00
1.00
0.10
100.00
100 100010
1 ms
0.1 ms
Current limit
due to R
DS(on)
Refer to figure 1 for MOSFET SOA
temperature derating coefficient
Figure 1 – MOSFET Safe OperatingArea
Derating Curve Figure 2 – MOSFET Safe OperatingArea
Drain Current versus Voltage
at TA= 25°C, Single Pulse
Terminal List Table
Number Name Description Functions
1 D Drain MOSFET drain
2 NC Clipped No connection
3 S/GND Source/ground terminal MOSFET source and ground
4 VCC Power supply terminal Input of power supply for control circuit
5 SS/OLP Soft Start/Overload Protection terminal Input to set delay for Overload protection and Soft Start operation
6 FB Feedback terminal Input for Constant Voltage Control and Burst (intermittent) Mode
oscillation control signals
7 OCP/BD Overcurrent Protection/Bottom Detection Input for overcurrent detection and bottom detection signals

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SANKEN ELECTRIC CO., LTD.
28103.33
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6756
Channel Junction Temperature, T
J
(°C)
E
AS
Temperature Derating Coefficient (%)
0
20
40
60
80
100
25 50 75 100 125 150
Time, t (s)
Transient Thermal Resistance, RQJC (°C/W)
0.001
0.010
0.100
1.000
10.000
100μ10μ10m1m 100m1μ
Ambient Temperature, TA(°C)
Power Dissipation, PD1 (W)
0
5
10
15
20
25
30
0 20 40 60 80 100 120 140 160
P
D1
= 1.3 W at T
A
≤25°C
Without heatsink
With infinite heatsink
P
D1
= 29 W at T
A
≤25°C
Figure 3 – MOSFETAvalanche Energy Derating Curve
VDD = 99 V, L = 20 mH, IL= 3.6 A Figure 4 – Transient Thermal Resistance
Figure 5 – MOSFET Power Dissipation versus Temperature

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SANKEN ELECTRIC CO., LTD.
28103.33
Quasi-Resonant Topology
Primary Switching Regulators
STR-W6756
ELECTRICAL CHARACTERISTICS
Characteristic Symbol Test Conditions Min. Typ. Max. Units
ELECTRICAL CHARACTERISTICS for Controller (MIC)1, valid at TA= 25°C, VCC = 20 V, unless otherwise specified
Power Supply Start-up Operation
Operation Start Voltage VCC(ON) VCC = 0→20 V 16.3 18.2 19.9 V
Operation Stop Voltage VCC(OFF) VCC = 20→8.8 V 8.8 9.7 10.6 V
Circuit Current In Operation ICC(ON) ––6mA
Circuit Current In Non-Operation ICC(OFF) VCC = 15 V – – 100 μA
Oscillation Frequency fosc 19 22 25 kHz
Soft Start Operation Stop Voltage VSSOLP(SS) VSS/OLP increasing 1.1 1.2 1.4 V
Soft Start Operation Charging Current ISSOLP(SS) VSS/OLP = 0 V –710 –550 –390 μA
Normal Operation
Bottom-Skip Operation Threshold Voltage 1 VOCPBD(BS1) –0.720 –0.665 –0.605 V
Bottom-Skip Operation Threshold Voltage 2 VOCPBD(BS2) –0.485 –0.435 –0.385 V
Overcurrent Detection Threshold Voltage VOCPBD(LIM) VOCP/BD falling –0.995 –0.940 –0.895 V
OCP/BD Terminal Outflow Current IOCPBD VOCP/BD = –0.95 V –250 –100 –40 μA
Quasi-Resonant Operation Threshold Voltage 1 VOCPBD(TH1) VOCP/BD falling 0.28 0.40 0.52 V
Quasi-Resonant Operation Threshold Voltage 2 VOCPBD(TH2) VOCP/BD rising 0.67 0.80 0.93 V
FB Terminal Threshold Voltage VFB(OFF) VFB rising 1.32 1.45 1.58 V
FB Terminal Inflow Current (Normal Operation) IFB(ON) VFB = 1.6 V 600 1000 1400 μA
Standby Operation
Standby Operation Start Voltage VCC(S) VCC = 0→15 V, VFB = 1.6 V 10.3 11.1 12.1 V
Standby Operation Start Voltage Interval VCC(SK) VCC(SK) = VCC(S) – VCC(OFF) 1.10 1.35 1.65 V
Standby Non-Operation Circuit Current ICC(S) VCC = 10.2 V, VFB = 1.6 V –2056μA
FB Terminal Inflow Current, Standby Operation IFB(S) VCC = 10.2 V, VFB = 1.6 V –414μA
FB Terminal Threshold Voltage, Standby Operation VFB(S) VCC = 15 V, VFB rising 0.55 1.10 1.50 V
Minimum On Time tON(MIN) 0.65 1.00 1.35 μs
Protection Operation
Maximum On Time tON(MAX) 27.5 32.5 39.0 μs
Overload Protection Operation Threshold Voltage VSSOLP(OLP) 4.0 4.9 5.8 V
Overload Protection Operation Charging Current ISSOLP(OLP) VSS/OLP = 2.5 V –16 –11 –6 μA
Overvoltage Protection Operation Voltage VCC(OVP) VCC = 0→30 V 25.5 27.7 29.9 V
Latch Circuit Holding Current2ICC(H) VCC(OFF)
– 0.3 V – 45 140 μA
Latch Circuit Release Voltage2VCC(La.OFF) VCC = 30→6 V, OVP operating 6.0 7.2 8.5 V
ELECTRICAL CHARACTERISTICS for MOSFET, valid at TA= 25°C, unless otherwise specified
Drain-to-Source Breakdown Voltage VDSS ID= 300 μA 650 – – V
Drain Leakage Current IDSS VDS = 650 V – – 300 μA
On Resistance RDS(on) ID= 2.2 A – – 0.73 Ω
Switching Time tf– – 400 ns
Thermal Resistance Rθch-F Channel to internal frame – – 1.5 °C/W
1Current polarity with respect to the IC: positive current indicates current sink at the terminal named, negative current indicates source at the
terminal named.
2The latch circuit means a circuit operated OVP and OLP.