18-bit, 2.5Msps SAR ADC achieves no latency
Steve Taranovich, Senior Technical Editor - April 13, 2012
Linear Technology Corp has announced the LTC2389-18, 18-bit no-cycle-latency SAR ADC. Offered as the industry's fastest such device, the part achieves 99.8dB SNR and -116dB THD at sample rates up to 2.5Msps. It operates from a single 5V supply and supports three pin-configurable analog input ranges for interfacing to multiple signal chains with a single device.
For the highest SNR performance, the ADC can be configured for fully differential (±4.096V) inputs. The pseudo-differential unipolar (0V to 4.096V) and bipolar (±2.048V) analog input ranges enable lower power single-ended drive and thus allow reduction of unwanted signals common to both inputs. This allows the designer to use it for demanding designs that require maximum signal swings at low power levels in noisy industrial environments.
Power dissipation is 162.5mW at 2.5Msps and 75µW in shutdown mode when not converting. The true no latency operation enables accurate one shot measurements even after lengthy idle periods with no minimum sample rate requirement. There is a flexible digital interface supporting 2.5Msps throughput.
Specifications are guaranteed over the -40°C to 125°C temperature range and the device is available in 48-pin 7×7-mm LQFP and QFN packages. Pricing is $33.90 each (1000). The DC1826A demonstration board is available to evaluate the LTC2389-18.