High-speed DSA targets BTS and test applications

June 25, 2012 // By Jean-Pierre Joosting
TriQuint Semiconductor has released a 7-bit digital step attenuator (DSA) that delivers the low insertion loss, high speed, linearity and and advanced, fine-grain resolution required by designers of base station transceivers, test equipment and many other similar applications. The TQP4M9083 provides up to 31.75 dB of attenuation in 0.25-dB steps and operates from 400 MHz to 3.5 GHz.

The TQP4M9083 uses a TTL / CMOS-compatible serial peripheral interface (SPI) controller for changing attenuation states; this maintains high attenuation accuracy over frequency and temperature. Switching speed is 118 n/s, input third-order intercept (IIP3) is +55 dBm, and insertion loss is 1.5 dB at 2 GHz.

The attenuator provides upgraded resolution with a 0.25 dB step size, which is a finer gradation compared to other standard 6-bit DSAs; these products typically offer 0.5 dB steps, including the company’s own TQP4M9072. Seeking constant improvement, the TQP4M9083 solution is offered with finer step gradation in the same 24-pin, 4 x 4 mm QFN package and pin-out as the TQP4M9072. This provides more choices for system gain control. The TQP4M9083 is designed to be robust, meeting stringent Class 1C HBM (up to 2 kV) electrostatic discharge (ESD) requirements.