|
|
PDF LX1571 Data sheet ( Hoja de datos )
| Número de pieza | LX1571 | |
| Descripción | PHASE MODULATED AC SYNCHRONOUS SECONDARY-SIDE CONTROLLER | |
| Fabricantes | Microsemi Corporation | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LX1571 (archivo pdf) en la parte inferior de esta página. Total 12 Páginas | ||
|
No Preview Available !
T H E I N F I N I T E P O W E R O F I N N O VAT I O N
P ATENT PENDING
L I N D O C #: 1570
LX1570/1571
PHASE MODULATED AC SYNCHRONOUS SECONDARY-SIDE CONTROLLER
PR E L I M I N A RY D ATA S H E E T
DESCRIPTION
The LX1570/71 series of controller ICs are
designed to provide all control functions in
a secondary-side regulator for isolated auxil-
iary or secondary power supplies. Auxiliary
or secondary-side controllers are used in a
variety of applications including multiple
output off-line power supplies, commonly
found in desktop computers, as well as tele-
communications applications. Although they
can be used in all secondary output applica-
tions requiring precision regulation, they are
mainly optimized for outputs delivering more
than 3A current where standard three-termi-
nal regulators lack the desired efficiency. For
these applications, the Mag Amp regulators
have traditionally been used. However, Mag
Amps have several disadvantages. First, be-
cause they have to withstand the maximum
input voltage during a short-circuit condition,
they are "over designed", typically by 2 times,
increasing the cost and size of the power
supply. Second, Mag Amps are inherently
leading edge modulators, so they can only
approach a certain maximum duty cycle, lim-
ited by the minimum delay and the mag-
netic BH loop characteristic of the Mag Amp
core. This forces an increase in the size of
the main transformer as well as the output
inductor, resulting in higher overall system
cost. The LX1570/71 eliminates all the
disadvantages of the Mag Amp approach
as well as improving system perfor-
mance and reducing overall system cost.
The LX1570/71 is a current mode control-
ler IC that controls the duty cycle of a switch
in series with the secondary AC output of
the power transformer in buck-derived ap-
plications, such as forward or bridge topolo-
gies. It offers features such as 100% duty
cycle operation for maximum energy trans-
fer, pulse-by-pulse and hiccup current limit-
ing with long off-time between the cycles
for reduced power dissipation, high-fre-
quency operation for smaller magnetics, soft-
start, and current mode control for excel-
lent dynamic response.
PRODUCT HIGHLIGHT
Aux Output
12V/8A
OUT
DRV
VCC
C.S.
VFB
LX1571
COMP
CT S.S.
GND
KEY FEATURES
p REPLACES COSTLY MAG-AMP CORES WITH
A LOW ON-RESISTANCE MOSFET
p LOOK-AHEAD SWITCHINGTM ENSURES
SWITCH TURN ON BEFORE THE AC INPUT
TO ACHIEVE 100% ENERGY TRANSFER
p LOWER OVERALL SYSTEM COST
p LOWER PEAK CURRENT STRESS ON THE
PRIMARY SWITCH
p ALLOWS HIGHER OPERATING FREQUENCY
AND SMALLER OUTPUT INDUCTOR
p EASY SHORT-CIRCUIT PROTECTION
p CURRENT MODE APPROACH ACHIEVES
EXCELLENT DYNAMIC RESPONSE
A P P L I C AT I O N S
s SECONDARY-SIDE REGULATOR IN OFF-LINE
POWER SUPPLIES
s COMPUTER POWER SUPPLIES, 3.3V OUTPUT
FOR NEW LOW-VOLTAGE PROCESSORS
AND MEMORIES
s TELECOMMUNICATION AND MILITARY
DC/DC CONVERTERS
A VA I L A B L E OP T I O N S P E R P A R T #
Part #
C.L.
Threshold
C.S.
Option
Application
LX1570 -0.2V
Resistive
Sensing
Output
Currents
< 4A
Current Output
LX1571 1V Transformer Currents
Sensing > 4A
Copyright © 1997
Rev. 0.9.3 1/97
TA (°C)
0 to 70
-40 to 85
-55 to 125
PACKAGE ORDER INFORMATION
M
Plastic DIP
8-pin
DM
Plastic
8-pin
SOIC
Y
Ceramic DIP
8-pin
LX157xCM
LX157xCDM
—
LX157xIM
LX157xIDM
—
— — LX157xMY
Note: All surface-mount packages are available in Tape & Reel.
Append the letter "T" to part number. (i.e. LX157xCDMT)
FOR FURTHER INFORMATION CALL (714) 898-8121
11861 WESTERN AVENUE, GARDEN GROVE, CA. 92841
1
1 page  
PRODUCT DATABOOK 1996/1997
PHASE MODULATED AC SYNCHRONOUS SECONDARY-SIDE CONTROLLER
PR E L I M I N A RY D ATA S H E E T
LX1570/1571
APPLICATION INFORMATION
100kHz - 150kHz
20V-30V
R2
300, 2W
AC(+)
D8
1N4937
20-30V, 100-150kHz
Secondary Transformer
Q1
IRLZ44
AC(-)
C1
0.1µF, 50V
T2
See Note 1
D1 1/2
L1
10µH (PE53700)
See Note 2
VOUT (+)
MBR2545CT
R5
0.02, 5W
D1 2/2
MBR2545CT
C9
1500µF
C10
1500µF
C12
1500µF
C11
1500µF
3.3V / 7A
VOUT (-)
D4
1N4148
C2
0.1µF
VIN (17 to 20V)
R6
324, 1%
R7
1k, 1%
R15
1M
R10
5k
1%
R11 R4
1.1k 47
U1
LX1570
1 S.S.
CT 8
2 VFB
VCC 7
3 COMP OUT DRV 6
4 C.S.
GND 5
C8
1000pF
C5
1µF
C4
0.047µF
Note 1. T2 Core = RM4Z
Np = 25T #28AWG
Ns = 25T #28AWG
2. For further information on PE53700 and PE64978,
contact Pulse Engineering at (619) 674-8100.
FIGURE 1 — THE LX1570 IN A TYPICAL 3.3V / 7A SECONDARY-SIDE POWER SUPPLY APPLICATION
Copyright © 1997
Rev. 0.9.3 1/97
5
5 Page 
PRODUCT DATABOOK 1996/1997
PHASE MODULATED AC SYNCHRONOUS SECONDARY-SIDE CONTROLLER
PR E L I M I N A RY D ATA S H E E T
LX1570/1571
12V/8A SCHEMATIC
80V
f = 100 to 150kHz
(+)
Secondary
Transformer
Voltage
R2, 2W
4.7k
C1, 0.1µF
250V
D8, 1N4937
Q1
IRF530
1 NS 3
6
NP
T2
4
(-)
D2
1N4935
R3
2.7k
1/2W
D4
1N4148
D3
1N4001
C2 0.1
R4 47W
1/2 D1
MUR1620
L1
140µH
Note: Linfinity provides a complete and
tested evaluation board. For further
information contact factory.
VOUT (+)
1/2 D1
MUR1620
43
12
T1
PE64978
(Note 1)
R5
475W
1%
C9
820µF
16V
C10
820µF
16V
12V/8A
VOUT (-)
VIN
C3
220µF
25V
C4
0.047µF
R12
1MW
Note 2
C6
0.56µF
Core =
T2
N
P
=
NS =
RM4Z
20T #32AWG
60T #32AWG
C5
1µF
D6
1N5819
8765
CT VCC OUT GND
DRV
U1, LX1571
S.S. VFB COMP C.S.
1234
C13
D5
1N5819
Pwr
Gnd
Signal Gnd
R8
SHORT
100W
R11
C8
D7
1N4148
R9
4.99W
1%
C7 1000pF
R6
3.83kW
1%
R7
1kW
1%
FIGURE 8 — THE LX1571 IN A 12V/8A SECONDARY-SIDE POWER SUPPLY APPLICATION
Unless otherwise noted all resistors are 1/4W, 5%.
Note 1: For further information on PE64978 contact Pulse Engineering at 619-674-8100.
Note 2: A high value resistor must be coupled back to "COMP" pin to insure proper operation under light load conditions.
Copyright © 1997
Rev. 0.9.3 1/97
11
11 Page | ||
| Páginas | Total 12 Páginas | |
| PDF Descargar | [ Datasheet LX1571.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LX1570 | PHASE MODULATED AC SYNCHRONOUS SECONDARY-SIDE CONTROLLER | Microsemi Corporation |
| LX1571 | PHASE MODULATED AC SYNCHRONOUS SECONDARY-SIDE CONTROLLER | Microsemi Corporation |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |