Texas Instruments ADS1284IRHFT

Overview

ADS1284IRHFT from Texas Instruments is a 31-bit, delta-sigma analog-to-digital converter (ADC) with integrated PGA, 2-channel multiplexer, and programmable digital filter. It delivers up to 130 dB SNR at 250 SPS in High-Resolution Mode, supports ±2.5 V analog supplies, operates from –40°C to +85°C, and targets seismic monitoring and high-accuracy instrumentation systems requiring ultra-low-noise signal acquisition.

For engineers reviewing the ADS1284IRHFT datasheet, ADS1284IRHFT pinout, ADS1284IRHFT application, or ADS1284IRHFT equivalent, key selection considerations include its 24-pin VQFN package, dual-input MUX architecture, selectable Low-Power/High-Resolution operating modes, on-chip offset/gain calibration, and support for linear/minimum-phase FIR filtering with programmable high-pass corner from 0.1 Hz to 10 Hz.

Technical Context

The ADS1284IRHFT employs a fourth-order, inherently stable delta-sigma modulator with PGA chop mode control and fast overrange detection. Its digital filter chain combines sinc, FIR, and IIR stages-configurable for linear or minimum-phase response-and includes a programmable high-pass filter with corner frequencies from 0.1 Hz to 10 Hz.

It features two differential analog inputs (AINP1/AINN1, AINP2/AINN2), independent reference inputs (VREFP/VREFN), dual supply domains (AVDD/AVSS, DVDD), and synchronous serial interface (DOUT/DIN/SCLK/CS) with DRDY and SYNC for precise timing control across multi-device systems.

Key Specifications

Pinout & Package

The ADS1284IRHFT is housed in a 24-pin, 5.0 mm × 4.0 mm VQFN package with exposed thermal pad (not electrically connected). Pin functions are validated per TI SBAS943A datasheet Rev. A.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS1283IRHFT and AD7768-1ACPZ, the ADS1284IRHFT uniquely combines 31-bit resolution, dual-input MUX, on-chip calibration, and sub-10 µV offset drift-making it the only option qualified for demanding geophysical instrumentation where sensor-level accuracy and long-term stability are non-negotiable.

Availability

ADS1284IRHFT is available at Aetrix Electronics and suitable for energy exploration, seismic monitoring, and high-accuracy instrumentation requiring stable component supply, long-lifecycle assurance, and traceable sourcing for field-deployed systems.

Supply support for ADS1284IRHFT 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 chain solutions.

The ADS1284IRHFT belongs to TI's high-resolution delta-sigma ADC product line, engineered specifically for geophysical sensing, seismic data acquisition, and ultra-low-noise instrumentation where DC accuracy, noise performance, and long-term stability are mission-critical.

FAQ

What is the maximum data rate supported by the ADS1284IRHFT in FIR filter mode?

The ADS1284IRHFT supports a maximum data rate of 4000 SPS in FIR filter mode. This rate balances resolution and speed for low-frequency geophysical signals, while maintaining 115 dB SNR at PGA = 1. Higher rates (up to 128 kSPS) are available in sinc-only mode but with reduced noise performance and no FIR filtering capability. The ADS1284IRHFT's FIR architecture is optimized for anti-aliasing and high-pass shaping-not high-speed streaming.

Does the ADS1284IRHFT support true differential reference inputs?

Yes, the ADS1284IRHFT accepts true differential reference inputs via VREFP and VREFN pins. The reference voltage range is 1 V to (AVDD – AVSS + 0.2 V), supporting standard 2.5 V or 5 V references. Input-referred full-scale range is calculated as ±VREF/(2 × PGA), and the device specifies 170 kΩ reference input impedance in Low-Power Mode-ensuring stable reference drive without external buffers in most configurations. This differential reference architecture enhances PSR and noise immunity in the ADS1284IRHFT.

How does the PGA chop mode affect noise performance and sensor compatibility in the ADS1284IRHFT?

The PGA chop mode in the ADS1284IRHFT reduces 1/f noise and improves DC stability, achieving <0.03 µV/°C offset drift. However, it increases input bias current-potentially incompatible with high-impedance hydrophones sensitive to current injection. When chop is disabled, input bias drops but 1/f noise rises, reducing SNR by ~2–3 dB at low frequencies. The ADS1284IRHFT allows register-controlled on-the-fly switching, enabling adaptive operation based on sensor type and measurement phase.

Can the ADS1284IRHFT be used with a single 3.3-V digital supply and split ±2.5-V analog supplies?

Yes, the ADS1284IRHFT is explicitly designed for mixed-supply operation: DVDD may be 1.65 V to 3.6 V (e.g., 3.3 V), while AVDD and AVSS support ±2.5 V (i.e., AVDD = +2.5 V, AVSS = –2.5 V relative to DGND). The datasheet confirms this configuration under Recommended Operating Conditions, and the device maintains full 130 dB SNR and 110 dB CMRR performance. Proper grounding-separating DGND and AGND planes tied at a single point-is essential for optimal ADS1284IRHFT performance.

What is the purpose of the MFLAG pin on the ADS1284IRHFT, and how is it used in system design?

The MFLAG pin on the ADS1284IRHFT is a dedicated modulator overrange indicator that asserts high immediately upon internal modulator saturation-faster than DRDY-based status polling. It enables real-time protection against clipping in seismic burst-mode acquisition, allowing host processors to discard corrupted samples or adjust PGA gain before the next conversion. Unlike software-flagged overrange detection, MFLAG provides cycle-accurate event timing, making it indispensable for high-fidelity waveform capture in the ADS1284IRHFT.