Datasheet LT8304, LT8304-1 (Analog Devices)

LT8304/LT8304-1 100VIN Micropower No-Opto Isolated Flyback Converter with 150V/2A Switch
FEATURES DESCRIPTION
n
3V to 100V Input Voltage Range
The LT®8304/LT8304-1 are monolithic micropower iso- n
2A, 150V Internal DMOS Power Switch
lated flyback converters. By sampling the isolated output n
Low Quiescent Current:
voltage directly from the primary-side flyback waveform, n
116µA in Sleep Mode
the parts require no third winding or opto-isolator for n
390µA in Active Mode
regulation. The output voltage is programmed with two n
Quasi-Resonant Boundary Mode Operation at
external resistors and a third optional temperature com-
Heavy Load
pensation resistor. Boundary mode operation provides a n
Low Ripple Burst Mode® Operation at Light Load
small magnetic solution with excellent load regulation. Low n
Minimum Load < 0.5% (Typ) of Full Output
ripple Burst Mode operation maintains high efficiency at n No Transformer Third Winding or Opto-Isolator light load while minimizing the output voltage ripple. A 2A, 150V DMOS power switch is integrated along with all the Required for Output Voltage Regulation n high voltage circuitry and control logic into a thermally Accurate EN/UVLO Threshold and Hysteresis n enhanced 8-lead SO package. Internal Compensation and Soft-Start n Temperature Compensation for Output Diode The LT8304/LT8304-1 operate from an input voltage range n Output Short-Circuit Protection of 3V to 100V and deliver up to 24W of isolated output n Thermally Enhanced 8-Lead SO Package power. The high level of integration and the use of boundary and low ripple Burst Mode operation result in a simple to
APPLICATIONS
use, low component count, and high efficiency applica- tion solution for isolated power delivery. The LT8304-1 is n Isolated Automotive, Industrial, Medical, Telecom specially optimized for high step-up output applications. Power Supplies L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks n Isolated Auxiliary/Housekeeping Power Supplies of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5438499, 7463497, 7471522.
TYPICAL APPLICATION 4V to 80VIN/5VOUT Isolated Flyback Converter Efficiency vs Load Current
100 VIN V + OUT 4V TO 80V 6:1 5V 220pF • 90 40µH 1.1µH 100µF VIN 100Ω ×3 10µF • 80 EN/UVLO SW V – OUT LT8304 309k 70 GND RFB 20mA TO 2.4A (VIN = 24V) 20mA TO 3.6A (V INTV R IN = 48V) CC REF 20mA TO 4.2A (V EFFICIENCY (%) IN = 72V) 60 1µF 100k 10k TC 50 VIN = 24V 8304 TA01a VIN = 48V VIN = 72V 40 0 0.6 1.2 1.8 2.4 3.0 3.6 4.2 LOAD CURRENT (A) 8304 TA01b 8304fa For more information www.linear.com/LT8304 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 Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Revision History Typical Application Related Parts