Microsemi Corp. RF Amplifiers LX5509LQ

The LX5509 is a power amplifier designed for 802.11ac/a/n applications, operating within the 5.15-5.85 GHz frequency range. It features a three-stage power amplifier architecture, active biasing, input/output matching, and an integrated harmonic filter. The device is built using an InGaP/GaAs Heterojunction Bipolar Transistor (HBT) process and requires a single positive voltage supply of 3.3V. This amplifier provides a power gain of approximately 28dB, with output power levels of 19-20 dBm at 1.8% dynamic EVM and 19.5-20.5 dBm at 3% dynamic EVM. The second and third harmonics are suppressed to below -45 dBm/MHz across the operating frequency range, thanks to the built-in harmonic filter. Additionally, the LX5509 includes an on-chip power detector, which aids in reducing bill of materials (BOM) costs and PCB space for power control applications. The product is packaged in a compact 20-pin quad flat no-lead (QFN) package measuring 4mm x 4mm, with a low profile of 0.9mm, making it suitable for space-constrained designs. The LX5509 is also RoHS compliant, ensuring it meets environmental standards for lead-free applications.