24-Bit Over-Sampling ADC with Configurable Flat Passband Digital Filter

The LTC2512-24 is a low noise, low power, high-performance 24-bit ADC with an integrated configurable digital filter. Operating from a single 2.5V supply, the LTC2512-24 features a fully differential input range up to ±VREF, with VREF ranging from 2.5V to 5.1V. The LTC2512-24 supports a wide common mode range from 0V to VREF simplifying analog signal conditioning requirements.

The LTC2512-24 simultaneously provides two output codes: (1) a 24-bit digitally filtered high precision low noise code, and (2) a 22-bit no latency composite code. The configurable digital filter reduces measurement noise by lowpass filtering and down-sampling the stream of data from the SAR ADC core, giving the 24-bit filtered output code. The 22-bit composite code consists of a 14-bit code representing the differential voltage and an 8-bit code representing the common mode voltage. The 22-bit composite code is available each conversion cycle, with no cycle of latency.

The digital filter can be easily configured for 4 different down-sampling factors by pin strapping. The configurations provide a dynamic range of 108dB at 400ksps and 117dB at 50ksps. The digital lowpass filter relaxes the requirements for analog anti-aliasing. Multiple LTC2512-24 devices can be easily synchronized using the SYNC pin.

Applications

* Seismology

* Energy Exploration

* Automated Test Equipment (ATE)

* High-Accuracy Instrumentation

* ±1ppm INL (Typ)* 117dB Dynamic Range (Typ) at 50ksps* 108dB Dynamic Range (Typ) at 400ksps* Guaranteed 24-Bits No Missing Codes* Configurable Digital Filter with Synchronization

* Relaxed Anti-Aliasing Filter Requirements

* Dual Output 24-Bit SAR ADC

* 24-Bit Digitally Filtered Low Noise Output* 14-Bit Differential + 8-Bit Common Mode No Latency Output

* Wide Input Common-Mode Range* Guaranteed Operation to 85°C* 1.8V to 5V SPI-Compatible Serial I/O* Low Power: 30mW at 1.6Msps* 24-Lead 7mm × 4mm DFN Package