The HMC539LP3 from Analog Devices is a RF Variable Attenuator with Frequency 0 to 4 GHz, Attenuation Range 0.25 to 7.75 dB, Attenuation Step 7.75 dB, Power 0.79 W, P1dB 28 dBm. Tags: IC, Programmable, Digital. More details for HMC539LP3 can be seen below.