Custom MMIC has launched a new product line of eight GaAs digital step attenuators (DSA) covering various bands from DC to 40 GHz.

The DSA family is intended to ease the design of high dynamic range receivers and instrumentation. These applications often must accomplish gain control of 50 dB or more. Fine step DSAs, with a least significant bit (LSB) of 0.5 dB for example, are often used for these applications. However, when a large attenuation change is needed, it is more efficient to use a coarse, i.e., lower bit count DSA of 2, 4 or even 8 dB LSB, as these offer lower insertion loss and fewer control lines for easier design implementation.

The table summarizes the eight new products now available, which cover up to 40 GHz with 0.5, 2 and 4 dB step size options. Both die and 3 mm x 3 mm QFN packaged versions are available.

The CMD281, CMD282, CMD281C3 and CMD282C3 represent initial offerings for coarse control: 2-bit DSAs with 2 and 4 dB step control. The CMD279, CMD280, CMD279C3 and CMD280C3 are the more traditional 0.5 dB step control devices with 15.5 dB range (i.e., 5-bit). All devices use a single control line per bit.

Click to expand the table.