STR-W6735 Datasheet, PDF (3/13 Pages) Allegro MicroSystems – Quasi-Resonant Topology Primary Switching Regulators

STR-W6735
Quasi-Resonant Topology
Primary Switching Regulators
4
VCC
+
Reg&
-
Iconst
OVP
Start
Stop
Burst
Burst
Control
Protection
latch
R
Q
S
DRIVE
Reg
Delay
RQ
S
+
-
OLP
OSC
MaxON
S
Q
R
BSD ^-
+
Bottom Selector
Soft Start
Counter
+
FB ^-
-
+
OCP
BD ₊
-
D₁
3
S/GND
FB ⁶
OCP/BD ₇
SS/OLP
5
Terminal List Table
Number
Name
1
D
2
NC
3
S/GND
4
VCC
5
SS/OLP
6
FB
7
OCP/BD
Description
Drain
Clipped
Source/ground terminal
Power supply terminal
Soft Start/Overload Protection terminal
Feedback terminal
Overcurrent Protection/Bottom Detection
Functions
MOSFET drain
No connection
MOSFET source and ground
Input of power supply for control circuit
Input to set delay for Overload protection and Soft Start operation
Input for Constant Voltage Control and Burst (intermittent) Mode
oscillation control signals
Input for overcurrent detection and bottom detection signals
Figure 1 – MOSFET Safe Operating Area
Derating Curve
100
Figure 2 – MOSFET Safe Operating Area
Drain Current versus Voltage
at T_A = 25°C, Single Pulse
100.00
80
60
40
20
0
0
25
50
75 100 125 150
Temperature, T_F (°C)
20.00
10.00
CduureretontRlim^DSit(on)
1.00
0.1 _ms
0.10
0.01
1
Refer to figure 1 for MOSFET SOA
temperature derating coefficient
10
100
Drain-to-Source Voltage, V_DS (V)
1000
28103.30-5
3
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