Texas Instruments ADS1252U

Overview

ADS1252U from Texas Instruments is a 24-bit delta-sigma analog-to-digital converter (ADC) with no missing codes, 19-bit effective resolution at up to 40kHz data rate, ±0.0015% INL, 2.5ppm rms noise, and differential input architecture. It operates from a single +5V supply and targets high-precision measurement in cardiac diagnostics, chromatography, and industrial process control.

For engineers reviewing the ADS1252U datasheet, ADS1252U pinout, ADS1252U application, or ADS1252U equivalent, this page delivers verified technical context, SO-8 package mapping, real-world timing and noise behavior, and two validated alternative ADCs for precision 24-bit sampling at ≤40kHz.

Technical Context

The ADS1252U employs a 4th-order delta-sigma modulator with fixed 64× oversampling ratio and a Sinc5 digital filter, delivering notch rejection at integer multiples of the data output rate - enabling precise 50Hz/60Hz power-line interference suppression. Its modulator clock is derived as CLK ÷ 6, so a 16MHz system clock yields 2.667MHz modulator frequency and 41.667kHz data rate.

It uses fully differential switched-capacitor input topology with 100dB common-mode rejection at DC and supports external reference voltages from 0.5V to 5V. The device features synchronous serial interface (SCLK/DOUT-DRDY), power-down mode (1µA quiescent), and SYNC capability for multi-converter synchronization without external logic.

Key Specifications

Pinout & Package

ADS1252U is housed in an SO-8 surface-mount package (D package), 4.9 mm × 3.9 mm, 1.75 mm height, with standard JEDEC MS-012AC footprint and gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-resolution delta-sigma ADC applications.

Compared with ADS1256IPW and AD7730BRUZ, the ADS1252U offers the highest data rate (41.7 kSPS) in a minimal SO-8 footprint with lowest pin count and simplest 2-wire interface - ideal for space-constrained, single-sensor, high-speed precision systems.

Availability

ADS1252U is available at Aetrix Electronics and suitable for cardiac diagnostics equipment, chromatography detectors, and industrial process transmitters requiring stable component supply and long-term manufacturability.

Supply support for ADS1252U includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in precision data converters and industrial-grade ICs.

The ADS1252U belongs to TI's precision delta-sigma ADC product line, engineered for high-dynamic-range measurement in medical, analytical, and process control instrumentation where 24-bit integrity and deterministic timing are non-negotiable.

FAQ

What is the maximum data rate achievable with the ADS1252U?

The ADS1252U achieves a maximum data rate of 41.667 kHz when operated with a 16 MHz system clock (CLK). This value is derived from the fixed 64× oversampling ratio and Sinc5 filter architecture. Data rate scales linearly with CLK frequency - e.g., 15.36 MHz CLK yields exactly 40 kHz - enabling precise tuning for anti-aliasing and notch placement.

Does the ADS1252U support bipolar input signals?

Yes, the ADS1252U supports true bipolar differential input signals. With VREF = 4.096 V, it accepts a ±4.096 V differential range referenced to –VIN. For ground-referenced bipolar inputs (e.g., ±2.5 V), a simple op-amp level-shift circuit using OPA2350 and four resistors (per Figure 1 in SBAS127D) is recommended to maintain linearity and CMRR.

How does the ADS1252U handle power-line interference rejection?

The ADS1252U leverages its Sinc5 digital filter to place deep notches at integer multiples of the data output rate. Setting the data rate to 50 Hz (via 19.2 kHz CLK) or 60 Hz (via 20.04 kHz CLK) provides >100 dB rejection at those frequencies. A 10 Hz data rate rejects both simultaneously with >135 dB attenuation - all without external analog filters.

What is the purpose of the DOUT/DRDY pin on the ADS1252U?

The DOUT/DRDY pin on the ADS1252U serves dual functions: it asserts LOW to indicate valid data is ready (DRDY mode), then shifts out the 24-bit conversion result MSB-first on the falling edge of SCLK (DOUT mode). This dual-role design minimizes pin count while supporting simple microcontroller interfacing with no additional handshaking lines.

Can the ADS1252U operate with a reference voltage lower than 4.096 V?

Yes, the ADS1252U accepts external reference voltages from 0.5 V to 5 V. Lower VREF (e.g., 2.5 V) reduces full-scale range and degrades effective resolution due to fixed internal noise floor - e.g., 2.5 ppm rms noise becomes 4 ppm of FSR at 2.5 V. For best noise performance, TI recommends VREF = 4.096 V with REF3140 buffer (Figure 2, SBAS127D).