LT3574 반도체 회로 부품 판매점
Isolated Flyback Converter Without an Opto-Coupler
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 Linear Technology |
Features
n 3V to 40V Input Voltage Range
n 0.65A, 60V Integrated NPN Power Switch
n Boundary Mode Operation
n No Transformer Third Winding or
Opto-Isolator Required for Regulation
n Improved Primary-Side Winding Feedback
Load Regulation
n VOUT Set with Two External Resistors
n BIAS Pin for Internal Bias Supply and Power
NPN Driver
n Programmable Soft-Start
n Programmable Power Switch Current Limit
n 16-Lead MSOP Package
Applications
n Industrial, Automotive and Medical Isolated
Power Supplies
LT3574www.DataSheet4U.com
Isolated Flyback Converter
Without an Opto-Coupler
Description
The LT®3574 is a monolithic switching regulator specifi-
cally designed for the isolated flyback topology. No third
winding or opto-isolator is required for regulation. The
part senses the isolated output voltage directly from the
primary side flyback waveform. A 0.65A, 60V NPN power
switch is integrated along with all control logic into a
16‑lead MSOP package.
The LT3574 operates with input supply voltages from
3V to 40V, and can deliver output power up to 3W with
no external power switch. The LT3574 utilizes boundary
mode operation to provide a small magnetic solution with
improved load regulation.
The output voltage is easily set with two external resistors
and the transformer turns ratio. Off-the-shelf transformers
are available for many applications.
L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks
and No RSENSE and ThinSOT are trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
Typical Application
VIN
12V TO 24V
5V Isolated Flyback Converter
10µF
357k
51.1k
VIN
SHDN/UVLO
0.22µF
PMEG6010
B340A
2k
3:1
•
50µH
5.6µH
•
TC
RILIM
SS
VC
LT3574
RFB
RREF
SW
GND TEST BIAS
80.6k
6.04k
28.7k 10k
59k
10nF 1nF
4.7µF
3574 TA01
VOUT+
5V
0.35A
22µF
VOUT–
Load Regulation
1.0
0.5 VIN = 24V
VIN = 12V
0
–0.5
–1.0
0
100 200 300 400 500 600 700
IOUT (mA)
3574 TA01b
3574f
LT3574
Absolute Maximum Ratings
SW.............................................................................60V
VIN, SHDN/UVLO, RFB, BIAS......................................40V
SS, VC, TC, RREF, RILIM...............................................5V
Maximum Junction Temperature........................... 125°C
Operating Junction Temperature Range
(Note 2).................................................. –40°C to 125°C
Storage Temperature Range................... –65°C to 150°C
www.DataSheet4U.com
Pin Configuration
GND 1
TEST 2
GND 3
SW 4
BIVAISN
5
6
SHDN/UVLO 7
GND 8
TOP VIEW
16 GND
15 TC
14
13
12
RRVCRFBEF
11
10
RSSILIM
9 GND
MS PACKAGE
16-LEAD PLASTIC MSOP
TJMAX = 125°C, θJA = 120°C/W, θJC = 21°C/W
order information
LEAD FREE FINISH
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LT3574EMS#PBF
LT3574EMS#TRPBF
3574
16-Lead Plastic MSOP
–40°C to 125°C
LT3574IMS#PBF
LT3574IMS#TRPBF
3574
16-Lead Plastic MSOP
–40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
E lectrical Characteristics The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VIN = 12V, unless otherwise noted.
PARAMETER
CONDITIONS
MIN TYP MAX
Input Voltage Range
l3
40
Quiescent Current
Soft-Start Current
SS = 0V
VSHDN/UVLO = 0V
SS = 0.4V
3.5
01
7
SHDN/UVLO Pin Threshold
UVLO Pin Voltage Rising
l 1.15 1.22 1.29
SHDN/UVLO Pin Hysteresis Current
Soft-Start Threshold
VUVLO = 1V
2 2.5 3
0.7
Maximum Switching Frequency
1000
Switch Current Limit
Minimum Current Limit
Switch VCESAT
RREF Voltage
RILIM = 10k
VC = 0V
ISW = 0.5A
VIN = 3V
0.65 0.9
1.1
100
150 250
1.21 1.23 1.25
l 1.20
1.25
RREF Voltage Line Regulation
RREF Pin Bias Current
IREF Reference Current
Error Amplifier Voltage Gain
3V < VIN < 40V
(Note 3)
Measured at RFB Pin with RREF = 6.49k
VIN = 3V
0.01 0.03
l 100 600
190
150
UNITS
V
mA
µA
µA
V
µA
V
kHz
A
mA
mV
V
%/V
nA
µA
V/V
3574f
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PDF 파일 내의 페이지 : 총 24 페이지
제조업체: Linear Technology
( linear )
LT3574 converter
데이터시트 다운로드 :
[ LT3574.PDF ]
[ LT3574 다른 제조사 검색 ]
국내 전력반도체 판매점
상호 : 아이지 인터내셔날
전화번호 : 051-319-2877
[ 홈페이지 ]
IGBT, TR 모듈, SCR, 다이오드모듈, 각종 전력 휴즈
( IYXS, Powerex, Toshiba, Fuji, Bussmann, Eaton )
전력반도체 문의 : 010-3582-2743
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