SAR ADC provides 20dB SNR improvement over pipelined ADCs

Linear Technology Corporation introduces the LTC2387-18, an ultrafast 15Msps, 18-bit successive approximation register (SAR) analogue-to-digital converter (ADC) with no cycle latency and no pipeline delay. The LTC2387-18 digitises wideband analogue signals up to the Nyquist frequency with very low distortion. Applications ranging from communications, high-speed imaging and instrumentation that traditionally utilise fast throughput pipelined ADCs can now achieve 20dB signal-to-noise ratio (SNR) improvement compared to pipelined ADC architectures.

The LTC2387-18 achieves an SNR of 95.7dB and realises −101dB total harmonic distortion (THD) while digitising a 1MHz analogue input signal. The high SNR and low distortion performance, combined with fast digitising throughput, enable the ADC to measure very low signal levels with greater precision and accuracy, thus improving image contrast and definition in high-end imaging applications. In addition, the no latency operation enables use in data acquisition systems that require fast control loops. To limit noise introduced from the digital outputs, the sampled data of this ADC is communicated via single- or dual-lane serial LVDS outputs to the host processor, providing good noise immunity for noise-sensitive applications.

The LTC2387-18 is the lead product in a pin-compatible family of 18- and 16-bit SAR ADCs with sampling rates ranging from 5Msps to 15Msps, releasing through 2015. The LTC2387-18 is now available in a 32-lead 5 × 5mm plastic QFN package, specified over the commercial and industrial temperature ranges, priced starting at US$38.95 in 1,000-piece quantities.