LDMOS RF power transistor for 500 MHz band
The STMicroelectronics PD54008L-E is an N-channel LDMOS RF power transistor designed for the 500 MHz band, delivering 8 W output power with a gain of 15 dB at a 7.5 V test voltage. LDMOS technology gives this device the ruggedness and linearity expected in UHF power amplifier stages, from driver to final output in base station or industrial RF generators.
Gain and output power — what 15 dB and 8 W mean for the design
15 dB gain at 500 MHz means a 0 dBm (1 mW) input drive produces roughly 8 W at the output — a practical gain block for driving a higher-power final stage or as the final stage in a moderate-power transmitter. The 8 W output power is rated at the 7.5 V test voltage; the absolute maximum drain voltage is 25 V, so the designer has headroom to trade supply voltage against output power and efficiency within the device's safe operating area. At 200 mA quiescent current (test condition), the bias point is set for Class AB operation — a common compromise between linearity and efficiency for modulated signals.
Package and thermal path
The 8-PowerVDFN package with PowerFLAT 5x5 footprint has an exposed thermal pad on the underside — the PCB land pattern must include a thermal via array and a copper plane to pull heat away from the die. The supplier device package is PowerFLAT 5x5, a 5 mm × 5 mm quad flat no-lead package optimised for low thermal resistance and low parasitic inductance at UHF.
Lifecycle and compliance
It is ROHS3 compliant, meeting the current restriction on hazardous substances for European and global markets.