Specifying A/D converters: considerations for IF-sampling applications.(LEADING inside: A series of engineering insights by Analog Devices.)(Advertisement)

EDN, September, 2005 by Mistler, Joanne

Choosing the ADC with the highest resolution or sampling speed is often not enough to satisfy the performance demands presented by IF-sampling architectures. ADCs for IF-sampling applications must support high input frequencies while also maintaining adequate SNR, SFDR, and SINAD performance. These features enable designers to eliminate one or more mixing stages and simplify filtering, thereby reducing cost and helping to meet end-system objectives.

Wideband signals having complex modulation--such as those used in many wireless communications, instrumentation, and radar systems--can exhibit time-varying bursts and transients. Furthermore, the data carried by these signals is often spread over multiple channels.

The ADC for these types of...