Dallas, Texas, USA: Newly developed programmable differential amplifiers (PDAs) combine the best features of fully differential amplifiers (FDAs) and digital variable gain amplifiers (DVGAs), says Texas Instruments. Gain can be modified without adjusting external resistors, replacing amplifiers, or reconfiguring each gain stage. In addition, unlike traditional DVGAs, the PDAs display consistent noise and distortion performance over the entire gain range.
The 2.4-GHz LMH6881 single-channel PDA and 2.4-GHz LMH6882 dual-channel PDA deliver optimised noise, distortion, and bandwidth performance over a 6dB to 26dB gain range. LMH6882’s channel gain matching of 0.2dB and phase matching of 1.5° enhance image rejection for wideband zero IF and I/Q sampling applications.
The devices’ programmable gain control eliminates the need for gain-setting resistors and their associated mismatch errors. Gain control can be implemented via an SPI bus or dedicated pins. There’s also no need for a balun, due to support that’s included for dc-ac coupling and single-ended-to-differential conversion.
Evaluation modules, as well as TINA-TI Spice models and reference designs, are available now.