DISCONTINUED PRODUCT
-- FOR REFERENCE ONL
Y
Data Sheet
28101
These devices are specifically designed to meet the requirements
for increased integration and reliability in off-line flyback (STR-S6401)
and forward (STR-S6401F) converters operating in a fixed-frequency
PWM mode. Each device incorporates the primary control and drive
circuits with an avalanche-rated power MOSFET. Crucial system
parameters such as switching frequency and maximum duty cycle are
fixed during manufacture. The STR-S6401 and STR-S6401F differ only
in their maximum duty cycle. Control circuit decoupling and layout are
optimized within each device.
Cycle-by-cycle and average-current limiting, soft start, under-
voltage lockout with hysteresis, and thermal shutdown protect the
device during all normal and overload conditions. The performance and
reliability of these devices, and their variable-frequency counterparts,
has been proven in substantial volume production.
The requirements of high dielectric isolation and low transient
thermal impedance and steady-state thermal resistance are satisfied in
an over-molded, 9-pin single in-line power package. Similar off-line
switching regulators, with output ratings to 800 V at 5 A, are also
available.
FEATURES
s
PWM Flyback Conversion or Forward Conversion
s
Output Power to 250 W
s
Pulse-by-Pulse Current Limiting
s
Fixed-Frequency 100 kHz PWM
s
Avalanche-Rated Power MOSFET Switch
s
Soft Start
s
Internal Under-Voltage Lockout and Thermal Shutdown
s
Low External Component Count
s
Over-Molded SIP with Isolated Heat Spreader
Always order by complete part number:
STR-S6401 or STR-S6401F .
+
SOURCE
DRAIN
UVLO
SIGNAL
GROUND
V IN
OVER-CURRENT
PROTECTION
Dwg. PK-003
SOFT
START
+
GATE
FDBK
PWM
POWER
GROUND
LATCH
REF.
1
2
3
4
5
6
7
8
9
OSC.
OFF-LINE SWITCHING REGULATORS
WITH POWER MOSFET OUTPUT
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, V
IN
............................ 35 V
Drain-Source Voltage, V
DS
............... 500 V
Drain Current, I
D
continuous ...................................
10 A
single pulse, t
w
1 ms ..................
40 A
Avalanche Energy, E
A
single pulse ............................... 500 mJ
Gate-Source Voltage, V
GS
................
20 V
Gate-Drive Current Range,
I
G
................................. -0.7 A to +1.5 A
Over-Current Protection Voltage Range,
V
OCP
............................. -0.3 V to +4.0 V
Insulation RMS Voltage,
V
WM(RMS)
..................................... 2000 V
Package Power Dissipation,
P
D
........................................ See Graph
FET Channel Temperature, T
J
...... +150
C
Internal Frame Temperature, T
F
... +125
C
Operating Temperature Range,
T
A
............................... -20
C to +125
C
Storage Temperature Range,
T
stg
............................. -30
C to +125
C
TM
STR-S6401
AND
STR-S6401F
STR-S6401
AND
STR-S6401F
OFF-LINE
SWITCHING REGULATORS
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
TM
FUNCTIONAL BLOCK DIAGRAM
ALLOWABLE PACKAGE POWER DISSIPATION
MAXIMUM SAFE OPERATING AREA
OSC.
S
Q
SOURCE
DRAIN
LATCH
1
2
UVLO
SIGNAL
GROUND
4
V
IN
OVER-CURRENT
PROTECTION
Rton
REF.
7
6
8
Dwg. FK-003
SOFT
START
5
0.2 V
+
GATE
3
FDBK
9
PWM
POWER
GROUND
+
Rtoff
R
60
40
20
20
60
100
3.2 W
140
LIMITED BY FRAME
TEMP. = +125
C MAX.
RECOMMENDED MAX.
FRAME TEMP. = +100
C
FREE AIR
62 W
0
TEMPERATURE in
C
ALLOWABLE PACKAGE POWER DISSIPATION in WATTS
MOUNTING SURFACE
TEMPERATURE
Dwg. GK-003
LIMITED
BY r
DS(on)
100
10
1.0
0.1
DRAIN-TO-SOURCE VOLTAGE in VOLTS
DRAIN CURRENT in AMPERES
Dwg. GK-004
0.3
3.0
30
3.0
10
30
100
300
LIMITED BY V max
DS
DC
NO HEAT SINK
NATURAL COOLING
T = +25
C
A
t = 10 ms SINGLE PULSE
w
t = 1 ms SINGLE PULSE
w
W
Copyright 1994, Allegro MicroSystems, Inc.
ALLOWABLE AVALANCHE ENERGY
ELECTRICAL CHARACTERISTICS
at T
A
= +25
C, V
IN
= 17 V, voltage measurements are referenced to
Signal Ground (pin 8) (unless otherwise noted).
Limits
Characteristic
Symbol
Test Conditions
Min.
Typ. Max.
Units
On-State Voltage
V
INT
Turn-on, increasing V
IN
14.4
16
17.6
V
Under-Voltage Lockout
V
INQ
Turn-off, decreasing V
IN
8.4
9.4
10.4
V
FET Leakage Current
I
DSS
V
DS
= 400 V
300
A
FET ON Resistance
r
DS(on)
V
GS
= 10 V, I
D
= 5 A
0.5
0.6
Forward Transconductance
g
fs
V
GS
= 10 V, I
D
= 5 A
9.2
S
FET Input Capacitance
C
iss
V
DS
=10 V, V
GS
=0 V, f=1 MHz
1800
pF
Propagation Delay Time
t
phl
Turn-on, 10% V
GS
to 10% V
DS
60
ns
t
plh
Turn-off, 90% V
GS
to 90% V
DS
140
ns
Oscillator Frequency
f
osc
93
100
107
kHz
Maximum ON Time
t
on
STR-S6401
5.1
5.7
6.5
s
STR-S6401F
3.8
4.5
5.2
s
Over-Current Threshold
V
OCP(th)
160
200
240
mV
OCP Current
I
OCP
-250
-400
-550
A
Feedback Current
I
FDBK
-1.8
mA
Soft Start Threshold Voltage
V
SS(th)
0.4
V
Soft Start Current
I
SS
V
SS
= 0 V
-100
A
Power Ground Current
I
PG
t
w
= 200 ns
-1.0
-1.5
A
Supply Current
I
IN(ON)
Operating
23
mA
I
IN(OFF)
Start up, V
IN
= 12 V
500
A
Insulation RMS Voltage
V
WM(RMS)
All terminals simultaneous reference
2000
V
metal plate against backside
Thermal Resistance
R
JM
FET channel to mounting surface
2.0
C/W
NOTES: Negative current is defined as coming out of (sourcing) the specified device terminal.
Typical Data is for design information only.
600
400
200
0
60
100
140
100
STARTING CHANNEL TEMPERATURE in
C
ALLOWABLE AVALANCHE ENERGY in mJ
Dwg. GK-009
300
500
0
20
40
80
120
160
SINGLE PULSE
DRAIN CURRENT = 10 A
SUPPLY VOLTAGE = 50 V
STR-S6401
AND
STR-S6401F
OFF-LINE
SWITCHING REGULATORS
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