ADS1251U

Overview

The ADS1251U is a single-channel, 24-bit ResolutionPLUS™ analog-to-digital converter (ADC) manufactured by Texas Instruments. It utilizes a Delta-Sigma architecture to provide true 24-bit no missing codes performance with a maximum data rate of 20 kSPS. The device operates on a single +5V supply, drawing a typical power consumption of 8 mW at full speed and 5 mW at 10 kSPS. It features a flexible two-wire synchronous serial interface compatible with SPI and I2C protocols. The input stage supports differential or single-ended signals, while the reference voltage is externally supplied within a range of 0.5 V to 5 V. Key linearity specifications include an integral nonlinearity (INL) of +/- 0.0015% FSR and a differential nonlinearity (DNL) of +/- 1 LSB.

Feature Summary

• Provides high-precision 24-bit resolution with wide dynamic range suitable for low-level signal measurement
• Features a flexible two-wire synchronous serial interface designed to facilitate low-cost isolation applications
• Supports multiple operating modes including synchronization mode for multi-device sampling and low-power shutdown mode

Applications

• Cardiac diagnostics and electrocardiogram (ECG) systems
• Industrial process control and monitoring
• Chromatography analysis equipment

Procurement Notes

Verify the specific ordering suffix when purchasing. The base part number ADS1251U typically indicates tube packaging, whereas suffixes such as /2K5 denote tape and reel quantities. Confirm moisture sensitivity levels and RoHS compliance status directly from the manufacturer's datasheet prior to procurement to ensure compatibility with assembly processes.

Selection Notes

Select the ADS1251U for applications requiring high accuracy at moderate speeds. It serves as a pin-compatible alternative to higher-speed variants like the ADS1252, though with reduced throughput. Ensure the design accommodates an external voltage reference, as the device does not include an internal one. Verify that the system clock requirements align with the desired output data rate.

Part Context

The ADS1251U belongs to the ADS1251 family of high-performance ADCs from Texas Instruments. This series is engineered for precision measurement tasks where noise performance and linearity are critical. The component shares architectural similarities with other members of the family but is distinct in its specific 20 kSPS sampling limit and single-channel configuration.

Replacement Considerations

The ADS1252U is a confirmed substitute offering identical pinout and functionality with an increased maximum data rate of 41 kSPS.