BLF888DSU

Overview

The BLF888DSU is a 600 W LDMOS RF power transistor designed for broadcast Doherty transmitter applications. It operates in the UHF band from 470 MHz to 860 MHz with a drain-source voltage of 50 V and quiescent current of 1.3 A. The device delivers an average output power of 250 W at 860 MHz with 21 dB gain and 45% efficiency under two-tone CW conditions. In pulsed operation, it achieves 580 W output power at 3 dB gain compression. The component features integrated ESD protection and internal input matching, housed in an earless flanged balanced ceramic SOT539B package.

Feature Summary

• High ruggedness capable of withstanding VSWR >= 40:1 through all phases
• One Doherty design covers the full bandwidth from 470 MHz to 860 MHz
• Internal input matching for ease of use
• Integrated ESD protection

Applications

• Broadcast transmitter applications in the UHF band
• Digital broadcasting

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm the exact package variant and compliance status. Ensure that the procurement channel provides valid traceability for this RF power component. Confirm RoHS compliance requirements match the project specifications before finalizing the purchase order.

Selection Notes

Select the BLF888DSU when designing ultra-wideband Doherty amplifiers requiring high efficiency and ruggedness across the 470 MHz to 860 MHz range. The device is optimized for digital and analog transmitter applications where excellent thermal stability and high power gain are critical performance factors.

Part Context

The BLF888DSU belongs to the BLF888D/BLF888DS family of UHF power LDMOS transistors manufactured by Ampleon. This series is engineered specifically for broadcast transmitter applications, offering a balance of high power output and reliability in demanding RF environments.

Replacement Considerations

The BLF888D (SOT539A) is the flanged counterpart within the same product family. Verify pinout compatibility and mechanical mounting differences between the earless SOT539B and flanged SOT539A packages before substitution.

FAQ

What is the maximum load mismatch the BLF888DSU can withstand?

The device is capable of withstanding a load mismatch corresponding to VSWR >= 40:1 through all phases at 810 MHz under rated load power conditions.

Does the BLF888DSU require external input matching networks?

No, the device features internal input matching designed to provide high gain and optimum broadband operation, simplifying circuit design.

What is the typical drain efficiency in a Doherty application?

In an ultra-wide Doherty application using a DVB-T signal, the drain efficiency typically ranges from 40% to 48% across the 470 MHz to 860 MHz frequency band.