HITTITE Microwave, represented in Australia by ASD Technology has released two GaAs MMIC digital attenuators with TTL/CMOS control. They are suitable for wireless infrastructure, test equipment and microwave radio applications.
The HMC470LP3 is a five-bit digital attenuator with a typical insertion loss of 1.4dB. It will provide any attenuation state from 1dB LSB to 31dB with a typical step error of ±0.2dB. The HMC472LP4 is a six-bit digital attenuator with a typical insertion loss of 1.5dB and will provide any attenuation state from 0.5dB LSB to 31.5dB with a typical step error of ±0.3dB.
The digital attenuators offer low insertion loss, fast switching speed and operation down to near dc without the need for an internally generated or externally supplied negative voltage. Both attenuators are matched to 50Ω at all attenuation levels, deliver minimal phase shift per bit and are TTL/CMOS compatible, requiring only a single control line per bit.
These low cost, low loss digital attenuators are housed in industry-standard QFN leadless surface mount packages.