Allegro s6525 Service Manual

STR-S6525

INTERIM DATA SHEET

OFF-LINE SWITCHING REGULATOR

(Subject to change without notice)
August 18, 1994

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

DRAIN

1

FAULT

OSC.

SOURCE

COMMON

SYNC

V

FDBK

SOFT START

FAULT-LATCH

TRIGGER

OVER-CURRENT

PROTECTION

2

3

4

5

IN

6

7

8

9

+

LATCH

RS

FAULT

UVLO

REF.

Dwg. PK-002-1

ABSOLUTE MAXIMUM RATINGS

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

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

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

1 ms Single-Pulse Drain Current,

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

Single-Pulse Avalanche Energy,

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

Feedback Input Current, I
Fault-Latch Trig. Input Current, IFL 1.0 mA

dc ≤ 25%, I

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

FLM

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

Over-Current Protection Voltage,

V

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

OCP

Insulation Voltage,V

NOT FOR NEW DESIGN

WM(RMS)

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

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

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

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

Storage Temperature Range,

T

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

stg

........ 20 mA

FDBK

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

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.

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 over­molded 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
growth and integration.

FEATURES

■ Constant OFF-Time Converter Operating Mode

■ Avalanche-Rated Power MOSFET Switch

■ Pulse-by-Pulse Current Limiting

■ Latched Over-Voltage and Thermal Protection

■ Maximum ON Time and OFF Time Set During Manufacture

■ Internal Under-Voltage Lockout with Hysteresis

■ Over-Molded SIP with Integral Isolated Heat Spreader

■ External Synchronization Capability

Always order by complete part number: STR-S6525 .

Data Sheet

28102.11

STR-S6525

4

3

512

9

6

7

8

OFF-LINE SWITCHING REGULATOR

FUNCTIONAL BLOCK DIAGRAM

V

IN

DRAIN

SOURCE

SOFT

START

2 kΩ

UVLO

REF.

OVER-VOLT.

PROTECT

R

FAULT

LATCH

SQ

TSD

OSC.

TRIGGER

0.01 µF
R

toff

OVER-CURRENT

+

PROTECTION

0.75 V
1000 pF

COMMON

Dwg. FK-002-1

FAULT-LATCH

TRIGGER

1 kΩ

R

ton

0.01 µF

20 kΩ

FDBK

SYNC

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

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

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

W
Copyright © 1994 Allegro MicroSystems, Inc.

STR-S6525

OFF-LINE SWITCHING REGULATOR

600

500

ALLOWABLE AVALANCHE ENERGY

400

300

200

100

ALLOWABLE AVALANCHE ENERGY in mJ

0

SINGLE PULSE
DRAIN CURRENT = 5 A
SUPPLY VOLTAGE = 50 V

20 40 80 120 160

0 60 100

STARTING CHANNEL TEMPERATURE in °C

140

Dwg. GK-009-1

ELECTRICAL CHARACTERISTICS at T

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

A

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.