Guerrilla RF Inc. is now sampling the GRF6402, the first of a new family of 0.25 dB step digital step attenuators (DSAs) under development. The devices utilize a state-of-the-art silicon-on-insulator process, which is now being leveraged for many of the company’s new signal chain offerings.
As a 7-bit, 31.75 dB range device, the GRF6402 utilizes a serial peripheral interface (SPI) for serial programming, as well as three externally defined address bits that allow up to eight DSAs to share a common SPI bus. The addressing scheme reduces the number of dedicated latch-enabled pins by a factor of eight times.
In addition to supporting traditional serial programming, the GRF6402 also includes a novel Rapid Fire
selection pin that allows the device to be immediately switched into a secondary pre-defined attenuation state – thus circumventing the delays associated with a typical SPI programming transaction. This feature is an enabler for test-driven development applications since a single DSA can now be used for transmit and receive modes. The Rapid Fire feature can also enable ‘fast attack’ signal chain protection schemes where it becomes imperative to quickly switch in additional attenuation as quickly as possible.
In terms of performance, the GRF6402 can cover the entire 50 MHz to 6 GHz range while maintaining precise and monotonic gain stepping. Glitching has been minimized to less than 2 dB for all steps. The device delivers up to 30.5 dBm of IP0.1dB, 55 dBm of IIP3, and a low IL of less than 1.4 dB at 2 GHz.
The GRF6402 comes in a 3 mm x 3 mm, 16-pin quad-flat no-leads package, and it adheres to a de facto standard footprint followed by many competitive alternatives.
