Wideband IF receiver chip provides highest dynamic range

November 14, 2014 // By Graham Prophet
The AD6676 “IF subsystem-on-a-chip” uses bandpass sigma delta A/D converter technology to digitise IF signals between 70 and 450 MHz with bandwidth up to 160 MHz.

Analog Devices' single chip wideband IF receiver subsystem allows designers of high-performance communications and instrumentation equipment to reduce the complexity of their receiver designs while simultaneously achieving frequency planning flexibility and previously unattainable instantaneous dynamic range.

The enabling technology behind the performance of the AD6676 is a highly programmable continuous-time bandpass sigma delta A/D converter (CTBPSD) topology which combines highly programmable analogue filtering functionality with high dynamic range conversion. The implementation in deep sub-micron CMOS allows the advantages of oversampling by providing digitised bandwidth of up to 160 MHz. This provides a combination of features that enables “reconfigurable radio” architectures for high-performance heterodyne systems:

  1. Dynamic Range: can be configured to achieve a noise figure of 13 dB, IIP3=36 dBM, noise spectral density (NSD) as low as -160 dBFS/Hz.
  2. Flexibility: can be configured for IF frequencies from 70 MHz up to 450 MHz, IF bandwidths from 20 MHz up to 160 MHz and input full scales from -14 dBm to +10 dBm. A profile feature allows the AD6676 to switch between up to four different IF and bandwidth configurations within 1 microsecond.
  3. Integration: CTBPSD architecture removes the need for IF SAW filters and gain blocks, significantly simplifying the interface to an RF mixer. The input provides a programmable digital attenuator, allowing gain control functionality with an easy-to-drive resistive interface. The AD6676 also includes a fully integrated clock synthesiser, digital down converter, and JESD204B serial interface. The net result is a receiver solution offering up to 70% board space savings.

Analog Devices is also providing a set of tools to ease adoption of this advanced technology. In addition to datasheets, evaluation boards and online technical support, ADI has created a live remote hardware drive capability that allows designers to run experiments on the AD6676, over an internet connection to an ADI lab, in real time.

A video is here; www.analog.com/AD6676video
Analog Devices; www.analog.com/AD6676