6-bit 0.5 dB Glitch-Free Wideband Digital Step Attenuator
Created: Aug 02, 2015
No description available.
In RF circuits, an RF attenuator is a device used to reduce the magnitude of a signal without appreciably distorting its waveform. This attenuation is required for protection to circuits that cannot handle high-magnitude signals. An attenuator also provides good impedance matching between two circuit stages and can also be used in a variety of areas where signal levels need to be controlled. The important characteristics of an RF attenuator are high-accuracy, low SWR (Standing Wave Ratio), flat frequency response and repeatability.
Featured in the above design is the F1912 digital step attenuator. The device is a 6-bit step attenuator optimized for demanding applications such as receivers and transmitters. The device is designed to have a very low insertion loss and low distortion (> +60 dBm IIP3) that makes it extremely accurate. The F1912 also includes a glitch-free technology, which results in low overshoot and ringing during MSB (Most Significant Bit) transitions. The device is also programmable through serial and 6 bit parallel interface. The serial control mode can be selected by floating VMODE (pin 13) or pulling it to a voltage that is greater than Logic Input High (VIH). In using the parallel control mode, the user has the option to run on direct parallel mode or latched parallel mode. The direct parallel mode is selected when VMODE (pin 13) is less than Logic Input Low (VIL) and LE (pin 5) is greater than VIH. The latched parallel mode is selected when VMODE is less than VIL and LE (pin 5) is toggled from less than VIL to greater than VIH. With this, attenuation can be selected up to 31.5 dB control range to fit different designs of RF applications.
The F1912 digital step attenuator is specifically used in applications such as base station 2G, 3G, 4G, TDD radio cards, repeaters, E911 systems, digital pre-distortion, point to point infrastructure, public safety infrastructure, WIMAX receivers and transmitters, military systems, JTRS radios, RFID handheld, portable readers and cable infrastructure.