Datasheet LT3748 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | 100V Isolated Flyback Controller |
| Pages / Page | 34 / 1 — Features. Description. 5V to 100V Input Voltage Range. 1.9A Average Gate … |
| File Format / Size | PDF / 542 Kb |
| Document Language | English |
Features. Description. 5V to 100V Input Voltage Range. 1.9A Average Gate Drive Source and Sink Current. Boundary Mode Operation
Model Line for this Datasheet
Text Version of Document
LT3748 100V Isolated Flyback Controller
Features Description
n
5V to 100V Input Voltage Range
The LT®3748 is a switching regulator controller specifically n
1.9A Average Gate Drive Source and Sink Current
designed for the isolated flyback topology and capable of n
Boundary Mode Operation
high power. It drives a low side external N-channel power n
No Transformer Third Winding or Opto-Isolator
MOSFET from an internally regulated 7V supply. No third
Required for Regulation
winding or opto-isolator is required for regulation as the n
Primary-Side Winding Feedback Load Regulation
part senses the isolated output voltage directly from the n V primary-side flyback waveform. OUT Set with Two External Resistors n INTVCC Pin for Control of Gate Driver Voltage The LT3748 utilizes boundary mode to provide a small n Programmable Soft Start magnetic solution without compromising load regulation. n Programmable Undervoltage Lockout Operating frequency is set by load current and transformer n Available in MSOP Package magnetizing inductance. The gate drive of the LT3748 combined with a suitable external MOSFET allow it to
applications
deliver load power up to several tens of watts from input voltages as high as 100V. n Isolated Telecom Converters n The LT3748 is available in a high voltage 16-lead MSOP High Power Automotive Supplies n package with four leads removed. Isolated Industrial Power Supplies n Military and High Temperature Applications L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5438499 and 7471522.
typical application 25W, 12V Output, Isolated Telecom Supply Output Load and Line Regulation
V + V OUT IN 4:1 12V 12.6 36V TO 72V 2A 10µF 412k 12.4 V 60.8µH 3.8µH 100µF EN/UVLO IN 243k 15.4k R – FB VOUT 12.2 RREF (V) 12.0 LT3748 6.04k V OUT 11.8 TC GATE V SS SENSE 11.6 IN = 72V VIN = 48V VC GND INTVCC 0.033Ω VIN = 36V 11.4 56.2k 2nF 10k 0 0.5 1.0 1.5 2.0 3748 TA01a LOAD CURRENT (A) 4700pF 4.7µF 3748 TA01b 3748fb For more information www.linear.com/LT3748 1 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 Package Description Typical Application Related Parts
Features Description
n
5V to 100V Input Voltage Range
The LT®3748 is a switching regulator controller specifically n
1.9A Average Gate Drive Source and Sink Current
designed for the isolated flyback topology and capable of n
Boundary Mode Operation
high power. It drives a low side external N-channel power n
No Transformer Third Winding or Opto-Isolator
MOSFET from an internally regulated 7V supply. No third
Required for Regulation
winding or opto-isolator is required for regulation as the n
Primary-Side Winding Feedback Load Regulation
part senses the isolated output voltage directly from the n V primary-side flyback waveform. OUT Set with Two External Resistors n INTVCC Pin for Control of Gate Driver Voltage The LT3748 utilizes boundary mode to provide a small n Programmable Soft Start magnetic solution without compromising load regulation. n Programmable Undervoltage Lockout Operating frequency is set by load current and transformer n Available in MSOP Package magnetizing inductance. The gate drive of the LT3748 combined with a suitable external MOSFET allow it to
applications
deliver load power up to several tens of watts from input voltages as high as 100V. n Isolated Telecom Converters n The LT3748 is available in a high voltage 16-lead MSOP High Power Automotive Supplies n package with four leads removed. Isolated Industrial Power Supplies n Military and High Temperature Applications L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5438499 and 7471522.
typical application 25W, 12V Output, Isolated Telecom Supply Output Load and Line Regulation
V + V OUT IN 4:1 12V 12.6 36V TO 72V 2A 10µF 412k 12.4 V 60.8µH 3.8µH 100µF EN/UVLO IN 243k 15.4k R – FB VOUT 12.2 RREF (V) 12.0 LT3748 6.04k V OUT 11.8 TC GATE V SS SENSE 11.6 IN = 72V VIN = 48V VC GND INTVCC 0.033Ω VIN = 36V 11.4 56.2k 2nF 10k 0 0.5 1.0 1.5 2.0 3748 TA01a LOAD CURRENT (A) 4700pF 4.7µF 3748 TA01b 3748fb For more information www.linear.com/LT3748 1 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 Package Description Typical Application Related Parts
