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
The company's Web site address is www.analog.com.
[Reprinted with kind permission from Linear Technology - Release Date: 9th February, 2017]