LTC2500 32-Bit Over-Sampling ADC with Configurable Digital Filter Linear Technology presents a 32-bit SAR ADC with 0.5 ppm linearity, providing 148 dB dynamic range

The LTC23500-32 are low noise, low power, high performance 32-bit ADCs from Linear Technology with an integrated configurable digital filter. Operating from a single 2.5 V supply, they feature a fully differential input range up to ±V REF , with V REF ranging from 2.5 V to 5.1 V. Supporting a wide common mode range from 0 V to V REF simplifying analog signal conditioning requirements.

The LTC23500-32 simultaneously provides two output codes: (1) a 32-bit digitally filtered high precision low noise code, and (2) a 32-bit no latency composite code. The configurable digital filter reduces measurement noise by low pass filtering and down-sampling the stream of data from the SAR ADC core, giving the 32-bit filtered output code. The 32-bit composite code consists of an overrange detection bit, a 24-bit code representing the differential input voltage and a 7-bit code representing the common mode input voltage. The 32-bit composite code is available each conversion cycle, with no cycle of latency.

The digital filter is highly configurable through the SPI compatible interface and features many distinct filter types that suit a variety of applications. The digital low pass filter relaxes the requirements for analog anti-aliasing. Multiple LTC2500 devices can be easily synchronized using the SYNC pin.

Features ±0.5 ppm INL (typ.)

104 dB SNR (typ.) at 1 Msps

148 dB dynamic range (typ.) at 61 sps

Guaranteed 32-bits no missing codes

Configurable digital filter with synchronization Relaxed anti-aliasing filter requirements

24-lead 7 mm x 4 mm DFN packages

Guaranteed operation to 85°C Dual output 32-bit SAR ADC 32-bit digitally filtered low noise output 24-bit differential + 7-bit common mode 1 Msps output with overrange detection

Wide input common-mode range

1.8 V to 5 V SPI-compatible serial I/O

Low power: 24 mW at 1 Msps Applications Seismology

Energy exploration Automatic test equipment

High accuracy instrumentation

Video: 32-Bit Over-Sampling ADC with Configurable Digital Filter