Allegro STRS6525 Datasheet

DRAIN

SOURCE

COMMON

SYNC

V

Data Sheet

28102.11

STR-S6525

OFF-LINE SWITCHING REGULATOR

– WITH POWER MOSFET OUTPUT

The STR-S6525 is specifically designed to meet the requirement

for increased integration and reliability in off-line flyback converters

1

FAULT

OSC.

2

3

4

5

IN

LATCH

RS

FAULT

UVLO

operating in a constant OFF-time mode. The device incorporates the
primary control and drive circuit with a discrete avalanche-rated high­voltage power MOSFET.

Crucial system parameters such as maximum ON time and OFF
time are fixed during manufacture. Local control circuit decoupling and
layout are optimized within the device.

FDBK

SOFT START

FAULT-LATCH

TRIGGER

OVER-CURRENT

PROTECTION

6

7

8

9

+

REF.

Cycle-by-cycle current limiting, soft start, under-voltage lock-out
with hysteresis, over-voltage protection, and thermal shutdown protect
the device during all normal and overload conditions. Over-voltage
protection, thermal shutdown, or an external fault signal be latched.
The dual requirements of dielectric isolation and low transient thermal
impedance and steady-state thermal resistance are satisfied in an over-

Dwg. PK-002-1

ABSOLUTE MAXIMUM RATINGS

molded single-in-line power package.

Proven in substantial volumes, this device and its fixed-frequency
counterparts represents a significant advance in off-line SMPS reliability

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

growth and integration.

Drain-Source Voltage, VDS.............. 600 V

Continuous Drain Current, ID............ 6.0 A

1 ms Single-Pulse Drain Current,

IDM................................................. 24 A

FEATURES

Single-Pulse Avalanche Energy,

EA.............................................. 400 mJ

Feedback Input Current, I

........ 20 mA

FDBK

Fault-Latch Trig. Input Current, IFL 1.0 mA

dc ≤ 25%, I

........................... -50 mA

FLM

■ Constant OFF-Time Converter Operating Mode

■ Avalanche-Rated Power MOSFET Switch

■ Pulse-by-Pulse Current Limiting

Soft-Start Output Current, ISS....... -3.0 mA

Over-Current Protection Voltage,

V

............................................. 3.5 V

OCP

Insulation Voltage,V

Package Power Diss., PD........ See Graph

DISCONTINUED PRODUCT

WM(RMS)

........... 2000 V

■ Latched Over-Voltage and Thermal Protection

■ Maximum ON Time and OFF Time Set During Manufacture

■ Internal Under-Voltage Lockout with Hysteresis

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

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

— FOR REFERENCE ONLY

Operating Temperature Range,

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

■ Over-Molded SIP with Integral Isolated Heat Spreader

■ External Synchronization Capability

Storage Temperature Range,

T

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

stg

Always order by complete part number: STR-S6525 .

™

STR-S6525

4

3

512

9

6

7

8

OFF-LINE
SWITCHING REGULATOR

FUNCTIONAL BLOCK DIAGRAM

V

IN

DRAIN

SOURCE

OVER-CURRENT
PROTECTION

COMMON

Dwg. FK-002-1

SOFT

START

FAULT-LATCH

TRIGGER

2 kΩ

UVLO

REF.

TSD

TRIGGER

1 kΩ

20 kΩ

R

ton

OVER-VOLT.

PROTECT

FDBK

R

SQ

0.01 µF

0.01 µF

FAULT

LATCH

SYNC

OSC.

R

toff

+

0.75 V
1000 pF

ALLOWABLE PACKAGE POWER DISSIPATION MAXIMUM SAFE OPERATING AREA

60

54 W

40

20

3.2 W

ALLOWABLE PACKAGE POWER DISSIPATION in WATTS

0

20 60 100

MOUNTING SURFACE
TEMPERATURE

FREE AIR

RECOMMENDED MAX.
FRAME TEMP. = +100°C

TEMPERATURE in °C

LIMITED BY FRAME
TEMP. = +125°C MAX.

140

Dwg. GK-003-2

115 Northeast Cutoff, Box 15036

100

30

10

3.0

1.0

DRAIN CURRENT in AMPERES

0.3

0.1

3.0

LIMITED
BY r

DS(on)

NO HEAT SINK
NATURAL COOLING
T = +25°C

A

10 30 100 300

t = 0.1 ms SINGLE PULSE

w

t = 1 ms SINGLE PULSE

w

INFINITE HEAT SINK

DRAIN-TO-SOURCE VOLTAGE in VOLTS

DS

LIMITED BY V max

1000

Dwg. GK-004-4

™

Worcester, Massachusetts 01615-0036 [phone]
Copyright © 1994 Allegro MicroSystems, Inc.

STR-S6525

OFF-LINE
SWITCHING REGULATOR

ALLOWABLE AVALANCHE ENERGY

600

500

SINGLE PULSE

400

300

200

100

ALLOWABLE AVALANCHE ENERGY in mJ

0

20 40 80 120 160

0 60 100

STARTING CHANNEL TEMPERATURE in °C

DRAIN CURRENT = 5 A
SUPPLY VOLTAGE = 50 V

140

Dwg. GK-009-1

ELECTRICAL CHARACTERISTICS

at TA = +25°C, VIN = 18 V, voltage measurements are referenced to

Common (pin 3) (unless otherwise noted).

Limits

Characteristic Symbol Test Conditions Min. Typ. Max. Units

On-State Voltage V
Under-Voltage Lockout V
Over-Voltage Threshold V

OVP(th)

FET Leakage Current I
FET ON Resistance r

DS(on)

Output Fall Time t
Maximum ON Time t
Minimum OFF Time t
Over-Current Threshold V
Feedback Threshold V

OCP(th)

FDBK(th)

Soft-Start Voltage V
Sync. Trigger Threshold Volt. V

SYNC(th)

Fault-Latch Trig. Threshold V
Fault-Latch Holding Current I
Fault-Latch Reset Voltage V
Insulation RMS Voltage V

WM(RMS)

INT
INQ

DSS

f
on
off

SS

FL(th)
INH

INQ

Turn-on, increasing V
Turn-off, decreasing V

IN

IN

14.4 – 17.6 V

9.0 – 11 V
26 – 31 V

VDS = 600 V – – 300 µA
VGS = 10 V, ID = 3 A – 1.0 1.25 Ω
VDD = 200 V, ID = 5 A, 10% to 90% V
I

= 0 27 – 33 µs

FDBK

DS

– – 250 ns

50 – 62 µs

700 – 800 mV

– 750 – mV

8.7 – 9.7 V

– 3.0 – V

680 – 880 mV
VIN reduced from 31 V to 8.5 V – 340 400 µA
IIN ≤ 20 µA, VIN reduced from 31 V 6.5 – 8.5 V
All terminals simultaneous reference 2000 – – V

metal plate against backside

Supply Current I

IN(ON)

I

IN(OFF)

Thermal Shutdown T
Thermal Resistance R

J

θJM

Operating 9.0 – 15 mA
Start up, VIN =14 V – – 200 µA

125 150 – °C
FET junction 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.