Texas Instruments ADS1254E/2K5

Overview

ADS1254E/2K5 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 20.8 kHz data rate, 1.8 ppm rms noise, and four differential input channels. It operates with separate analog (5 V) and digital (1.8–3.6 V) supplies and supports external reference voltages from 0.5 V to 5 V, targeting high-precision measurement in portable instrumentation and industrial process control.

For engineers reviewing the ADS1254E/2K5 datasheet, ADS1254E/2K5 pinout, ADS1254E/2K5 application, or ADS1254E/2K5 equivalent, key selection considerations include its 24-bit no-missing-codes performance, 20.8 kHz maximum output rate with Sinc5 digital filtering, low-power 4.3 mW operation at full speed, SSOP-20 package footprint, and support for synchronized multi-converter systems via SCLK hold.

Technical Context

The ADS1254E/2K5 employs a fourth-order delta-sigma modulator with fixed 64× oversampling ratio and a Sinc5 digital filter that requires five conversion cycles (1920 system clock cycles at 8 MHz) to fully settle. Its modulator clock is derived by dividing the system clock (CLK) by six, enabling precise notch placement at integer multiples of the data output rate for targeted 50/60 Hz rejection.

Input channel selection is controlled by CHSEL0/CHSEL1 pins, supporting four differential pairs (CH1–CH4), while the analog front end features fully differential switched-capacitor architecture delivering 102 dB CMR at 60 Hz and 88 dB PSRR. The device supports both DRDY and DOUT modes on a single bidirectional pin, with timing strictly governed by CLK and SCLK edges.

Key Specifications

Pinout & Package

ADS1254E/2K5 is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65 mm pitch, optimized for compact PCB layouts in space-constrained instrumentation. Thermal pad is not present; maximum lead temperature is +300°C for 10 seconds during reflow.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS1255IPW and AD7730BRUZ, the ADS1254E/2K5 uniquely combines 20.8 kHz data rate, four-channel differential mux, SCLK-based synchronization, and external reference flexibility - making it irreplaceable in portable chromatography analyzers and multi-sensor industrial controllers where timing coherence and voltage scalability are mandatory.

Availability

ADS1254E/2K5 is available at Aetrix Electronics and suitable for cardiac diagnostics equipment, portable chromatography systems, and precision industrial process controllers requiring stable component supply and long-term production continuity.

Supply support for ADS1254E/2K5 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 signal chains.

The ADS1254E/2K5 belongs to TI's precision delta-sigma ADC product line, engineered specifically for high-resolution, low-noise measurement in portable and industrial instrumentation where 24-bit integrity, multi-channel flexibility, and power efficiency are critical.

FAQ

What is the maximum data output rate supported by the ADS1254E/2K5?

The ADS1254E/2K5 achieves a maximum data output rate of 20.8 kHz when operated with an 8 MHz system clock (CLK). This rate scales linearly with CLK frequency - for example, a 3.84 MHz CLK yields 10 kHz output. The device maintains 19-bit effective resolution up to this maximum rate, as confirmed by TI SBAS213B Figure 4.

Does the ADS1254E/2K5 support true bipolar input ranges such as ±5 V or ±10 V?

Yes, the ADS1254E/2K5 supports bipolar inputs via external op-amp circuitry. TI Application Note SBAS213B Figure 2 shows validated resistor networks using OPA4350 to interface ±2.5 V, ±5 V, and ±10 V signals. The ADC itself accepts differential inputs up to ±VREF, so a 4.096 V reference enables ±4.096 V differential range - extended to ±10 V with proper level-shifting amplification.

How does the ADS1254E/2K5 achieve 50 Hz and 60 Hz power-line rejection?

The ADS1254E/2K5 uses its Sinc5 digital filter's inherent notch characteristics: setting the data output rate to exactly 50 Hz or 60 Hz places deep nulls at those frequencies and all harmonics. As shown in SBAS213B Figures 5–6, this provides >100 dB rejection at line frequency without analog filtering - achieved by configuring CLK to 19.2 kHz (for 50 Hz) or 23.04 kHz (for 60 Hz).

Can multiple ADS1254E/2K5 devices be synchronized, and how is it implemented?

Yes, the ADS1254E/2K5 supports hardware synchronization: holding the SCLK line HIGH for 4–20 consecutive DOUT/DRDY cycles resets all modulators simultaneously. Valid conversions begin on the falling edge of SCLK, ensuring phase-aligned sampling across multiple devices - essential for coherent multi-channel acquisition in chromatography or motor control systems.

What are the absolute maximum ratings for analog input voltage on the ADS1254E/2K5?

The ADS1254E/2K5 specifies analog input voltage limits relative to AGND: each input (e.g., CH1+) must remain between AGND – 0.3 V and AVDD + 0.3 V. With AVDD = 5 V, this defines a safe operating range of –0.3 V to +5.3 V per pin. Differential input voltage must not exceed ±VREF, and continuous input current must stay below ±10 mA per pin, per SBAS213B Absolute Maximum Ratings table.