LTC2500-32 SAR ADC is a new approach for precision measurement
A successive approximation register (SAR) analogue to digital converter (ADC) from Analog Devices, has 0.5ppm linearity to provide a 148dB dynamic range. The LTC2500-32 is a high precision SAR ADC provides a new and enabling approach for precision measurement applications, blending the high accuracy and speed of Linear Technology’s proprietary SAR ADC architecture with flexible integrated digital filters to optimise system signal bandwidth and ease analogue anti-aliasing filter requirements.
The LTC2500-32 simultaneously provides two outputs. The first is a 32bit low noise, digitally filtered output that achieves up to 148dB of dynamic range. The second is a 32bit 1Msample/s no latency output comprising an over-range detection bit, a 24bit representation of the input voltage difference, and a 7bit representation of the common mode input voltage. The no-latency output is matched to the digitally filtered output, avoiding the mismatch and drift that typically occur in applications requiring an additional faster ADC to monitor signal integrity in parallel with a precision ADC, says Analog Devices. The wide input common mode range and high common mode rejection ratio (CMRR) enable the LTC2500-32 to interface signals with varying common mode. This simplifies the analogue signal chain. Each of the two outputs provides a highly accurate representation of the voltage difference applied between the two input terminals.
The low noise density of LTC2500-32 produces 148dB of dynamic range at 61sample/s and 104dB at 1Msample/s. It also offers what is claimed to be unrivalled linearity of 0.5ppm typical and 2ppm guaranteed maximum INL value, and low gain and offset drift over wide temperature ranges. Combined, these features enable high precision measurements in noisy environments, such as in industrial automation applications. The integrated configurable digital filter offers seven filter types and 13 downsampling factors, providing trade-off combinations for bandwidth, filter response and noise performance for each application.
The LTC2500-32 is is available now in commercial and industrial (-40 to +85 degree C) temperature grades. The DC2222A evaluation board for the LTC2500 SAR ADC family is also available.