Datasheet LT3574 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | Isolated Flyback Converter Without an Opto-Coupler |
| Pages / Page | 24 / 1 — 3V to 40V Input Voltage Range. 0.65A, 60V Integrated NPN Power Switch. … |
| File Format / Size | PDF / 296 Kb |
| Document Language | English |
3V to 40V Input Voltage Range. 0.65A, 60V Integrated NPN Power Switch. Boundary Mode Operation
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LT3574 Isolated Flyback Converter Without an Opto-Coupler Features Description n
3V to 40V Input Voltage Range
The LT®3574 is a monolithic switching regulator specifi- n
0.65A, 60V Integrated NPN Power Switch
cally designed for the isolated flyback topology. No third n
Boundary Mode Operation
winding or opto-isolator is required for regulation. The n
No Transformer Third Winding or
part senses the isolated output voltage directly from the
Opto-Isolator Required for Regulation
primary side flyback waveform. A 0.65A, 60V NPN power n
Improved Primary-Side Winding Feedback
switch is integrated along with all control logic into a
Load Regulation
16-lead MSOP package. n VOUT Set with Two External Resistors The LT3574 operates with input supply voltages from n BIAS Pin for Internal Bias Supply and Power 3V to 40V, and can deliver output power up to 3W with NPN Driver no external power switch. The LT3574 utilizes boundary n Programmable Soft-Start mode operation to provide a small magnetic solution with n Programmable Power Switch Current Limit improved load regulation. n 16-Lead MSOP Package The output voltage is easily set with two external resistors applications and the transformer turns ratio. Off-the-shelf transformers are available for many applications. n Industrial, Automotive and Medical Isolated Power Supplies 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
5V Isolated Flyback Converter
V
Load Regulation
IN 12V TO 24V B340A V + OUT 10µF 3:1 5V 357k 1.0 0.22µF 2k V 0.35A IN • SHDN/UVLO 50µH 5.6µH 22µF VIN = 24V 51.1k PMEG6010 • 0.5 V – OUT 80.6k V R IN = 12V FB LT3574 R 0 REF TAGE ERROR (%) TC 6.04k RILIM SS –0.5 SW OUTPUT VOL VC GND TEST BIAS 28.7k 10k 59k –1.0 0 100 200 300 400 500 600 700 10nF 1nF 4.7µF IOUT (mA) 3574 TA01b 3574 TA01 3574f Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration order information Electrical Characteristics Typical Performance Characteristics Pin Functions block diagram Operation Applications Information typical Applications Package Description Typical Application Related Parts
3V to 40V Input Voltage Range
The LT®3574 is a monolithic switching regulator specifi- n
0.65A, 60V Integrated NPN Power Switch
cally designed for the isolated flyback topology. No third n
Boundary Mode Operation
winding or opto-isolator is required for regulation. The n
No Transformer Third Winding or
part senses the isolated output voltage directly from the
Opto-Isolator Required for Regulation
primary side flyback waveform. A 0.65A, 60V NPN power n
Improved Primary-Side Winding Feedback
switch is integrated along with all control logic into a
Load Regulation
16-lead MSOP package. n VOUT Set with Two External Resistors The LT3574 operates with input supply voltages from n BIAS Pin for Internal Bias Supply and Power 3V to 40V, and can deliver output power up to 3W with NPN Driver no external power switch. The LT3574 utilizes boundary n Programmable Soft-Start mode operation to provide a small magnetic solution with n Programmable Power Switch Current Limit improved load regulation. n 16-Lead MSOP Package The output voltage is easily set with two external resistors applications and the transformer turns ratio. Off-the-shelf transformers are available for many applications. n Industrial, Automotive and Medical Isolated Power Supplies 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
5V Isolated Flyback Converter
V
Load Regulation
IN 12V TO 24V B340A V + OUT 10µF 3:1 5V 357k 1.0 0.22µF 2k V 0.35A IN • SHDN/UVLO 50µH 5.6µH 22µF VIN = 24V 51.1k PMEG6010 • 0.5 V – OUT 80.6k V R IN = 12V FB LT3574 R 0 REF TAGE ERROR (%) TC 6.04k RILIM SS –0.5 SW OUTPUT VOL VC GND TEST BIAS 28.7k 10k 59k –1.0 0 100 200 300 400 500 600 700 10nF 1nF 4.7µF IOUT (mA) 3574 TA01b 3574 TA01 3574f Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration order information Electrical Characteristics Typical Performance Characteristics Pin Functions block diagram Operation Applications Information typical Applications Package Description Typical Application Related Parts
