Linear Technology’s New 100V 5W Flyback Regualator
The LT8303 does not require a opto-isolator or third winding for regulation
Linear Technology has released the H-grade version of the LT8303, a monolithic flyback regulator
with guaranteed operation for junction temperatures as high as 150°C. By sampling the isolated output voltage directly
from the primary-side flyback waveform, the part requires no opto-isolator or third winding for regulation.
The LT8303 operates over a 5.5V to 100V input voltage range, has a 0.45A/150V integrated DMOS power switch and delivers up to 5 watts of output power, making it well suited for a wide range of telecom, datacom, automotive, industrial, medical and military applications.
The output voltage is set with only one external resistor and the transformer turns ratio. Several off-the-shelf transformers, identified in the data sheet, can be used for numerous applications. The LT8303 operates in boundary mode, which is a variable frequency current mode control switching scheme, typically resulting in ±1% output voltage load and line regulation. Boundary mode enables the use of a smaller transformer compared to equivalent continuous conduction mode designs. The high level of integration and the use of low ripple Burst Mode® operation result in a simple to use, low component count and high efficiency application solution for isolated power delivery.
Additional features include output overload and short-circuit protection, 70µA no load operating quiescent current, internal loop compensation along with an accurate enable and undervoltage lockout with hysteresis.
Features of the LT8303 include:
- VIN Range from 5.5V to 100V
- Up to 5 Watts of Output Power
- Onboard 0.45A, 150V Integrated DMOS Power Switch
- Off-the-Shelf Power Transformers
- No Opto-Isolator, LT1431 or Third Winding Required for Voltage Feedback
- 70µA Quiescent Current
- Boundary Mode Operation
- VOUT Set with One External Resistor
- Internal Loop Compensation
- Accurate Input Enable & Undervoltage Lockout with Hysteresis
For more information on the LT8303 Monolithic Flyback Regulator, visit the Analog Devices Website at
Linear Technology LT8303 product page
The company's Web site address is www.analog.com.
[Reprinted with kind permission from Linear Technology - Release Date: 9th February, 2017]