Latest GaAs Digital Step Attenuators are Offered in Die and QFN Package Versions

Press Release Summary:

The GaAs Digital Step Attenuators include 2 bit (CMD281, CMD282, CMD281C3 and CMD282C3) and 5 bit models (CMD279, CMD280, CMD279C3 and CMD280C3) with step control of 2, 4 and 0.5 dB. The units offer a gain control of 50 dB and ease the design of high dynamic range receivers and instrumentation. The attenuators feature a control voltage of 0/ -5 V and input IP3 of 42 dBm.

Original Press Release:

Custom MMIC Launches New Digital Attenuator Product Line Covering DC-40 GHz

Chelmsford, MA – August 27, 2018 – Custom MMIC, a leading developer of performance driven monolithic microwave integrated circuits (MMICs), has launched a new product line of GaAs Digital Step Attenuators (DSA).

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

Table 1 summarizes the eight new products are now available covering up to 40GHz, with 0.5, 2 and 4dB step size options. Die and 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 CMD279CMD280, CMD279C3 and CMD280C3 are the more traditional 0.5dB step control devices with 15.5dB range (5 bit). All devices are single control line per bit.


Digital Step          Frequency       Number of      Insert. Loss           Attn. Range       Step Size           Input                  Control              Package
Attenuator             (GHz)                  Bits                 (dB)                         (dB)                    (dB)             IP3 (dBm)          Voltage (V)
Part Number 

CMD282                 DC - 40                 2                      1.5                         12                          4                   42                          0 / -5                    DIE

CMD281                 DC - 40                 2                      1.2                           6                          2                   42                          0 / -5                    DIE

CMD280                 DC - 30                 5                        3                          15.5                      0.5                  42                         0 / -5                    DIE

CMD281C3            DC - 22                 2                      1.5                           6                           2                   42                          0 / -5               3x3 mm QFN

CMD282C3            DC - 22                 2                      1.9                          12                          4                   42                          0 / -5               3x3 mm QFN

CMD280C3            DC – 18                5                       3                           15.5                       0.5                 42                           0 / -5               3x3 mm QFN

CMD279C3             2 - 18                   5                      3.5                         15.5                       0.5                  42                          0 / +5               3x3 mm QFN

CMD279                  2 - 30                  5                       3.5                         15.5                       0.5                  42                          0 / +5                   DIE

Visit for more information and to download full datasheets and S-parameter data.

About Custom MMIC

Custom MMIC is a leading developer of performance driven monolithic microwave integrated circuits (MMICs). Embracing their customers’ challenges, the company offers both a growing family of high-performance MMIC standard products and innovative custom-design services. Their engineering team is highly experienced in a broad range of III-V processes (e.g. GaAs, GaN, InP, InGaP) and has longstanding relationships with the leading foundries. Custom MMIC specializes in RF through millimeter-wave circuits serving diverse markets including wireless and wired communications, satellite, radar systems, cellular infrastructure and instrumentation. The company was founded in 2006 and is based in Chelmsford, MA. For more information, visit

Company Contact: 
John Greichen

Custom MMIC 


Agency Contact: 

Leah Giunta

Strand Marketing


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