LT8303IS5#TRPBF

Overview

The LT8303IS5#TRPBF is a micro-power, high-voltage isolated flyback converter from Analog Devices. It operates with an input voltage range of 5.5 V to 100 V and delivers up to 5 W of isolated output power. The device integrates a 450 mA, 150 V DMOS power switch within a 5-lead TSOT-23 package. Key electrical parameters include a quiescent current of 70 μA in shutdown mode and 280 μA in active mode. It utilizes boundary conduction mode for heavy loads and low-ripple burst mode for light loads, achieving minimum full output load regulation of less than 0.5% typically.

Feature Summary

• Eliminates the need for optocouplers or transformer auxiliary windings by sampling the isolated output voltage directly from the primary-side flyback waveform.
• Integrates internal compensation and soft-start circuitry to minimize external component count and simplify design implementation.
• Supports programmable output voltage via a single external resistor while maintaining precise enable/UVLO thresholds with hysteresis.

Applications

• Telecommunications power supplies
• Data communication power systems
• Automotive power architectures
• Industrial power equipment
• Medical power devices
• Auxiliary and housekeeping power circuits

Procurement Notes

Verify the specific suffix IS5 against the official datasheet to confirm industrial temperature rating compliance. Ensure the TRPBF designation matches the required reel packaging format for surface-mount assembly processes. Cross-reference the manufacturer part number with authorized distributor catalogs to validate authenticity and traceability before finalizing procurement orders.

Selection Notes

Select this component when designing isolated DC-DC converters requiring high input voltages up to 100 V without using optocouplers. The TSOT-23-5 package suits applications demanding compact footprints and low pin counts. Consider the 450 mA internal switch limit and 5 W power capability when sizing magnetic components for the target application requirements.

Part Context

This part belongs to the LT8303 family of no-opto isolated flyback regulators. It shares functional similarities with the LT8300 and LT8302 series but differs in package type, switch current ratings, and input voltage specifications. The IS5 variant specifically denotes industrial temperature grade performance within the broader product line.

Replacement Considerations

LT8303ES5#TRPBF: Commercial grade equivalent with identical electrical characteristics but different operating temperature range.

FAQ

How does the LT8303 regulate output voltage without an optocoupler?

It regulates the output by directly sampling the isolated output voltage from the primary-side flyback waveform during the off-time, eliminating the need for an optocoupler or auxiliary transformer winding.

What is the maximum output power capability of this device?

The LT8303 provides up to 5 W of isolated output power, supported by an integrated 450 mA, 150 V DMOS power switch.