Allegro STRS6401F, STRS6401 Datasheet

DISCONTINUED PRODUCT

— FOR REFERENCE ONLY

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, under­voltage 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

■ PWM Flyback Conversion or Forward Conversion

■ Output Power to 250 W

■ Pulse-by-Pulse Current Limiting

■ Fixed-Frequency 100 kHz PWM

■ Avalanche-Rated Power MOSFET Switch

■ Soft Start

■ Internal Under-Voltage Lockout and Thermal Shutdown

■ Low External Component Count

■ 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.

123456789

OSC.

OFF-LINE SWITCHING REGULATORS

– WITH POWER MOSFET OUTPUT

ABSOLUTE MAXIMUM RATINGS

Supply Voltage, VIN............................ 35 V

Drain-Source Voltage, VDS............... 500 V

Drain Current, I

D

continuous ................................... ±10 A

single pulse, tw ≤1 ms .................. ±40 A

Avalanche Energy, E

A

single pulse............................... 500 mJ

Gate-Source Voltage, VGS................ ±20 V

Gate-Drive Current Range,

IG................................. -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,

PD........................................ See Graph

FET Channel Temperature, TJ...... +150°C

Internal Frame Temperature, TF... +125°C
Operating Temperature Range,

TA............................... -20°C to +125°C

Storage Temperature Range,

T

stg

............................. -30°C to +125°C

™

STR-S6401

AND

STR-S6401F

STR-S6401

AND

STR-S6401F

OFF-LINE
SWITCHING REGULATORS

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]

™

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

R

ton

REF.

7

6

8

Dwg. FK-003

SOFT

START

5

0.2 V

+

GATE

3

FDBK

9

PWM

POWER

GROUND

+

R

toff

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 TA = +25°C, VIN = 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

VDS = 400 V – – 300 µA

FET ON Resistance r

DS(on)

VGS = 10 V, ID = 5 A – 0.5 0.6 Ω

Forward Transconductance g

fs

VGS = 10 V, ID = 5 A – 9.2 – S

FET Input Capacitance C

iss

VDS=10 V, VGS=0 V, f=1 MHz – 1800 – pF

Propagation Delay Time t

phl

Turn-on, 10% VGS to 10% V

DS

–60– ns

t

plh

Turn-off, 90% VGS 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 µs
STR-S6401F 3.8 4.5 5.2 µs

Over-Current Threshold V

OCP(th)

160 200 240 mV

OCP Current I

OCP

-250 -400 -550 µA

Feedback Current I

FDBK

– -1.8 – mA

Soft Start Threshold Voltage V

SS(th)

– – 0.4 V

Soft Start Current I

SS

VSS = 0 V – -100 – µA

Power Ground Current I

PG

tw = 200 ns – -1.0 -1.5 A

Supply Current I

IN(ON)

Operating – 23 – mA

I

IN(OFF)

Start up, VIN = 12 V – – 500 µA

Insulation RMS Voltage V

WM(RMS)

All terminals simultaneous reference 2000 – – V
metal plate against backside

Thermal Resistance R

θJM

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