Texas Instruments ADS1254EG4

Overview

ADS1254EG4 from Texas Instruments is a 24-bit delta-sigma analog-to-digital converter (ADC) with no missing codes, 19-bit effective resolution at 20.8 kHz data rate, 1.8 ppm rms noise, four differential input channels, and external reference support from 0.5 V to 5 V. It operates with AVDD = 5 V and DVDD = 1.8–3.6 V, delivering 4.3–6.5 mW power consumption in active mode for high-precision measurement in portable instrumentation and industrial process control.

For engineers reviewing the ADS1254EG4 datasheet, ADS1254EG4 pinout, ADS1254EG4 application, or ADS1254EG4 equivalent, this page provides verified technical context, SSOP-20 package mapping, real-world use-value analysis for cardiac diagnostics and chromatography, and two validated alternative ADCs with documented functional and parametric differences.

Technical Context

The ADS1254EG4 employs a fourth-order delta-sigma modulator with fixed 64× oversampling ratio and a Sinc5 digital filter that requires five full conversions (1920 system clock cycles) to settle. Its modulator clock is derived by dividing the 8 MHz system clock by 6, yielding a 1.333 MHz modulator frequency and 20.8 kHz data output rate.

It supports synchronous two-wire serial interface with independent SCLK (up to 8 MHz) and system CLK (8 MHz), DOUT/DRDY dual-mode pin operation, channel selection via CHSEL0/CHSEL1, and flexible bipolar input configuration using external op-amp circuitry. Common-mode rejection reaches 102 dB at 60 Hz, and input impedance scales inversely with CLK frequency (e.g., 125 kΩ at 8 MHz).

Key Specifications

Pinout & Package

ADS1254EG4 is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65 mm pitch, 7.2 mm × 5.3 mm body size, and exposed thermal pad (not electrically connected). The package supports surface-mount reflow and meets JEDEC MS-013AC standards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS1254EG4, ADS1255IPWR offers improved linearity in a pin-compatible package but sacrifices two differential inputs, while AD7739BRUZ adds integrated gain and SPI compatibility at the cost of lower max data rate and non-interchangeable packaging - selection depends on input topology, gain needs, and interface constraints.

Availability

ADS1254EG4 is available at Aetrix Electronics and suitable for cardiac diagnostics equipment, liquid/gas chromatography analyzers, and precision industrial process controllers requiring stable component supply, long-lifecycle assurance, and traceable sourcing.

Supply support for ADS1254EG4 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 over 50 years of innovation in precision data converters and industrial signal chains.

The ADS1254EG4 belongs to TI's precision delta-sigma ADC product line, engineered specifically for high-dynamic-range, low-noise measurement in medical, analytical, and industrial instrumentation where 24-bit integrity and 20 kHz bandwidth are mandatory.

FAQ

What is the maximum data rate supported by the ADS1254EG4?

The ADS1254EG4 achieves a maximum data output rate of 20.8 kHz when operated with an 8 MHz system clock. This rate scales linearly with CLK frequency - for example, a 3.84 MHz clock yields 10 kHz output. The –3 dB bandwidth is 0.2035× the data rate, so at 20.8 kHz it is 4.24 kHz, making ADS1254EG4 suitable for anti-aliasing-limited wideband sensing without external filters.

Does the ADS1254EG4 support bipolar input signals?

Yes, the ADS1254EG4 supports true bipolar input ranges (e.g., ±2.5 V, ±5 V, ±10 V) when configured with an external three-op-amp level-shifting circuit as shown in Figure 2 of the datasheet. The internal architecture is fully differential and referenced to VREF, so bipolar operation requires external circuitry to translate ground-referenced signals into the ADS1254EG4's differential input range.

How does the Sinc5 digital filter in the ADS1254EG4 enable 50/60 Hz rejection?

The ADS1254EG4's Sinc5 filter places deep notches at integer multiples of the data output rate. By setting the data rate to exactly 50 Hz or 60 Hz - achieved by configuring CLK to 19.2 kHz or 23.04 kHz respectively - the first notch aligns with mains frequency, providing >100 dB rejection. At 10 Hz data rate, both 50 Hz and 60 Hz fall into deep stopband regions, enabling simultaneous rejection.

What is the purpose of the DOUT/DRDY pin's dual-mode operation in the ADS1254EG4?

The DOUT/DRDY pin serves two time-multiplexed functions: it pulses LOW (DRDY mode) to signal availability of new 24-bit conversion data, then shifts that data MSB-first (DOUT mode) on the falling edge of SCLK. This dual-mode design minimizes pin count while maintaining deterministic timing - the ADS1254EG4 requires the host to read all 24 bits before the next DRDY pulse to avoid data loss.

Can the ADS1254EG4 operate with different analog and digital supply voltages?

Yes, the ADS1254EG4 features independent analog (AVDD = 4.75–5.25 V) and digital (DVDD = 1.8–3.6 V) supplies. This separation allows direct interfacing with 1.8 V or 3.3 V microcontrollers while maintaining optimal analog performance at 5 V, reducing need for level shifters and improving noise immunity between domains - a key advantage in mixed-signal industrial designs.