Datenblatt-pdf.com

STR-F6600 Schematic ( PDF Datasheet ) - Allegro Micro Systems

Teilenummer STR-F6600
Beschreibung Off-line Quasi-resonant Flyback Switching Regulators
Hersteller Allegro Micro Systems
Logo Allegro Micro Systems Logo 



Gesamt 16 Seiten
		
STR-F6600 Datasheet, Funktion
Series STR-F6600
www.DataSheet4U.com
INTERIM DATA SHEET
OFF-LINE QUASI-RESONANT
(Subject to change without notice)
February 22, 2000
FLYBACK SWITCHING REGULATORS
The Series STR-F6600 is specifically designed to satisfy the require-
ments for increased integration and reliability in off-line quasi-resonant
flyback converters. The series incorporates a primary control and drive
circuit with discrete avalanche-rated power MOSFETs.
FDBK
OSC.
LATCH
Covering the power range from below 25 watts up to 300 watts for
100/115/230 VAC inputs, and up to 150 watts for 85 to 265 VAC
universal input, these devices can be used in a range of applications,
from battery chargers and set top boxes, to televisions, monitors, and
UVLO industrial power supply units.
OVP
TSD
Cycle-by-cycle current limiting, under-voltage lockout with hyster-
esis, over-voltage protection, and thermal shutdown protects the power
supply during the normal overload and fault conditions. Over-voltage
protection and thermal shutdown are latched after a short delay. The
latch may be reset by cycling the input supply. Low-current startup and
a low-power standby mode selected from the secondary circuit completes
a comprehensive suite of features. The series is provided in a five-pin
Dwg. PK-011-1
overmolded TO-3P style package, affording dielectric isolation without
compromising thermal characteristics.
ABSOLUTE MAXIMUM RATINGS
at TA = +25°C
Control Supply Voltage, VIN . . . . . . . . 35 V
Drain-Source Voltage, VDS
Series STR-F6620 . . . . . . . . . . . . 450 V
Series STR-F6630 . . . . . . . . . . . . 500 V
Series STR-F6650 . . . . . . . . . . . . 650 V
Series STR-F6670 . . . . . . . . . . . . 900 V
Drain Switching Current, ID . . .
Peak Drain Current, IDM . . . . . .
Avalanche Energy, EAS . . . . . . .
OCP/FB Voltage Range,
See Table
See Table
See Table
VOCP . . . . . . . . . . . . . . . -0.3 V to +6 V
Package Power Dissipation, PD
control (VIN x IIN(ON)) . . . . . . . . . 0.8 W
total . . . . . . . . . . . . . . . . . . . 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,
TS . . . . . . . . . . . . . . . . -40°C to +125°C
FEATURES
s Flyback Operation with Quasi-Resonant Soft Switching
for Low Power Dissipation and EMI
s Rugged Avalanche-Rated MOSFET
s Choice of MOSFET Voltage and rDS(on)
s Full Over-Current Protection (no blanking)
s Under-Voltage Lockout with Hysteresis
s Over-Voltage Protection
s Direct Voltage Feedback
s Low Start-up Current (<400 µA)
s Low-Frequency, Low-Power Standby Operation
s Overmolded 5-Pin Package
Always order by complete part number, e.g., STR-F6652 .
TM






STR-F6600 Datasheet, Funktion
Series STR-F6600
OFF-LINE
QUASI-RESONANT FLYBACK
SWwIwTw.DCatHaShIeNet4GU.coRm EGULATORS
Functional Description and Operation (cont’d)
The drive winding voltage is set such that in normal
operation the C2 voltage is above the specified maximum
shutdown voltage (11 V) and below the specified mini-
mum over-voltage threshold (20.5 V).
In applications where there is a significant variation in
load current, the VIN terminal voltage may vary, as shown
in figure 4. This is due to peak charging of C2. In this
case, adding a resistor in the range of a few ohms to tens of
ohms in series with the rectifier diode D2 will bring the
voltage variation within limits.
VIN
comparator output pre-terminates the oscillator, which
turns off the MOSFET drive signal.
The MOSFET is turned on again when either cSS
discharges or a quasi-resonance signal is detected on pin 1.
Fixed 50 µs Off-Time: Soft-Start Mode
This is the mode of operation in the absence of a quasi-
resonance signal on pin 1 (see figure 5), and occurs at
IOUT
Figure 4 – Output Current IOUT – Terminal Voltage VIN
Soft Start, Quasi Resonant and Voltage Regulation
Refer to the Functional Block Diagram and the Typical
Application Diagram (figure 6). The internal oscillator
uses the charge/discharge of an internal 4700 pF capacitor
(cSS) to generate the MOSFET drive signals.
The regulator has two modes of operation:
1. fixed 50 µs off time (soft start) and
2. demagnetization sensing quasi-resonant mode —
normal operation.
In both cases, voltage regulation is achieved by taking
the composite optocoupled voltage error and superimposed
drain current ramp (current-mode control) and comparing
this to an internal 0.73 V reference. The FBK/OCP
Figure 5 – Soft-Start Operation
startup and in overload. It also can be commanded exter-
nally to provide low-power standby operation.
In the absence of a feedback signal (such as at startup,
or a short circuit) the drain current ramp, sensed across R5
and noise filtered by R4/C5 appears on pin 1. When the
ramp voltage on C5 exceeds the 0.73 V reference signal,
the FBK/OCP comparator changes state, shutting down the
oscillator and turning off the MOSFET. Thus the voltage
on cSS is held high (6.5 V) by the comparator. When the
comparator changes state, cSS discharges via rSS; the
voltage on cSS ramps down until it reaches 3.7 V. The
oscillator turns on the MOSFET. This ramp-down time is
internally trimmed to 50 µs. The comparator changes state
again and the cycle repeats. Thus in the absence of
feedback, the current-sense resistor R5 accurately controls
the MOSFET maximum current.
6
115 Northeast Cutoff, Box 15036
TM
Worcester, Massachusetts 01615-0036 (508) 853-5000

6 Page







STR-F6600 pdf, datenblatt
Series STR-F6600
OFF-LINE
QUASI-RESONANT FLYBACK
SWwIwTw.DCatHaShIeNet4GU.coRm EGULATORS
MOSFET Safe Operating Areas (cont)
(single pulse at TA = +25°C)
STR-F6672
50
STR-F6676
50
15
5
1.5
0.5
0.15
LIMITED
BY rDS(on)
TA = +25°C
tw
=
1
ms
tw = 0.1 ms SINGLE
SINGLE PULSE
PULSE
0.05
3.0
10 30 100 300
DRAIN-SOURCE VOLTAGE in VOLTS
Dwg. GK
15
5
LIMITED
BY rDS(on)
1.5
tw
=
1
ms
tw = 0.1 ms SINGLE
SINGLE PULSE
PULSE
0.5
TA = +25°C
0.15
0.05
3.0
10 30 100 300
DRAIN-SOURCE VOLTAGE in VOLTS
Dwg. GK
S.O.A. Derating
1.0
0.8
0.6
0.4
0.2
Drain Switching Current (ID) Derating
20
TA = -20°C to +125°C
16
STR-F6656
12
STR-F6654
8.0
STR-F6652 & STR-F6672
STR-F6653
4.0 STR-F6672
0
25
50 75 100
FRAME TEMPERATURE in °C
125
Dwg. G
0
0.8
0.9 1.0
1.1
SOURCE-TO-GROUND VOLTAGE (V2-V5) in VOLTS
Dwg
12
115 Northeast Cutoff, Box 15036
TM
Worcester, Massachusetts 01615-0036 (508) 853-5000

12 Page


SeitenGesamt 16 Seiten
PDF Download[ STR-F6600.PDF ]

Link teilen




Besondere Datenblatt

TeilenummerBeschreibungHersteller
STR-F6600Off-line Quasi-resonant Flyback Switching RegulatorsAllegro Micro Systems
Allegro Micro Systems

TeilenummerBeschreibungHersteller
CD40175BC

Hex D-Type Flip-Flop / Quad D-Type Flip-Flop.

Fairchild Semiconductor
Fairchild Semiconductor
KTD1146

EPITAXIAL PLANAR NPN TRANSISTOR.

KEC
KEC


www.Datenblatt-PDF.com    |   2020   |  Kontakt  |   Suche