Texas Instruments ADS1258IRTCR

Overview

ADS1258IRTCR from Texas Instruments is a 16-channel, 24-bit delta-sigma analog-to-digital converter with single-cycle settled data, fixed-channel scan rate up to 125 kSPS and auto-scan rate up to 23.7 kSPS per channel, low noise (2.8 µV_RMS at 1.8 kSPS), ±2.5 V bipolar or +5 V unipolar operation, and integrated system monitoring for temperature, supply, reference, gain, and offset - used in high-precision multi-channel instrumentation systems.

For engineers reviewing the ADS1258IRTCR datasheet, ADS1258IRTCR pinout, ADS1258IRTCR application, or ADS1258IRTCR equivalent, key selection considerations include its QFN-48 package, SPI interface timing compliance, on-chip 32.768 kHz crystal oscillator, 8 GPIOs, programmable sensor bias current sources, and differential MUX output for external signal conditioning prior to ADC input.

Technical Context

The ADS1258IRTCR integrates a fourth-order delta-sigma modulator followed by a fifth-order sinc digital filter optimized for low-noise performance, delivering no missing codes across its 24-bit resolution. Its flexible 16-input multiplexer supports 16 single-ended or 8 differential configurations with break-before-make switching in Auto-Scan mode.

Onboard PLL generates 15.729 MHz system clock from 32.768 kHz crystal (or accepts external clock via CLKIO), with buffered clock output for synchronizing microcontrollers or additional converters. Internal system monitor registers provide real-time readback of temperature, AVDD/AVSS, VREF, offset, and gain - all accessible via SPI commands without external sensors.

Key Specifications

Pinout & Package

ADS1258IRTCR is housed in a 48-pin QFN package (7 mm × 7 mm, 0.5 mm pitch) with exposed thermal pad connected internally to AVSS. Pin assignments are fully defined per TI SBAS297G datasheet Rev. March 2011.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS1256IPWR and AD7768-1ACPZ, the ADS1258IRTCR uniquely combines 16-channel count, 23.7 kSPS auto-scan, integrated crystal oscillator, 8 GPIOs, and full system monitoring - making it optimal for compact, self-contained, high-channel-count data loggers requiring minimal external support components.

Availability

ADS1258IRTCR is available at Aetrix Electronics and suitable for medical diagnostic instrumentation, industrial process monitoring, avionics sensor hubs, and high-speed test equipment requiring stable component supply and long-term production continuity.

Supply support for ADS1258IRTCR 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 company specializing in analog and embedded processing technologies, with leadership in precision data converters and industrial-grade ICs.

The ADS1258IRTCR belongs to TI's high-precision delta-sigma ADC product line, designed specifically for fast-scan, multi-channel measurement systems in medical, avionics, and industrial automation where accuracy, integration, and reliability are critical.

FAQ

What is the maximum channel scan rate supported by the ADS1258IRTCR in Auto-Scan mode?

The ADS1258IRTCR supports a maximum Auto-Scan data rate of 23.7 kSPS per channel, completing a full 16-channel acquisition in under 698 µs. This performance is achieved using its internal fifth-order sinc digital filter and fourth-order delta-sigma modulator, with single-cycle settling guaranteed across all configured channels. The ADS1258IRTCR maintains 24-bit resolution and no missing codes at this rate.

Does the ADS1258IRTCR require an external crystal, or can it operate with an external clock source?

The ADS1258IRTCR supports both clocking options: it can drive a 32.768 kHz crystal connected to XTAL1/XTAL2 (with 22 nF PLLCAP to AVSS), or accept an external clock signal up to 16 MHz applied to CLKIO. The CLKSEL pin selects between modes - low enables the internal oscillator, high disables it and enables external clock input. The ADS1258IRTCR outputs a buffered 15.729 MHz clock on CLKIO when using the crystal.

How does the ADS1258IRTCR handle open-sensor detection?

The ADS1258IRTCR implements open-sensor detection using two programmable current sources (1.5 µA or 24 µA) routed through selected analog inputs. By measuring the resulting voltage drop across the sensor, the device detects open circuits - a feature documented in the "Open-Sensor Detection" section of the ADS1258IRTCR datasheet. This eliminates need for external comparators or discrete bias circuitry.

What is the purpose of the MUXOUTP and MUXOUTN pins on the ADS1258IRTCR?

The MUXOUTP and MUXOUTN pins provide access to the differential output of the internal 16-channel analog multiplexer, before the signal reaches the ADC core. This allows external signal conditioning - such as filtering, amplification, or galvanic isolation - to be inserted between the multiplexer and ADC input (ADCINP/ADCINN). The ADS1258IRTCR's architecture explicitly supports this configuration to improve noise immunity and dynamic range in harsh environments.

Can the ADS1258IRTCR operate with a unipolar analog supply, and what are the valid voltage ranges?

Yes, the ADS1258IRTCR supports unipolar operation with AVSS = 0 V and AVDD = +5 V, enabling compatibility with single-supply sensor interfaces. Valid analog supply ranges are AVSS = –2.6 V to 0 V and AVDD = AVSS + 4.75 V to AVSS + 5.25 V. For bipolar operation, AVSS = –2.5 V and AVDD = +2.5 V yields a ±2.5 V input range. The ADS1258IRTCR's absolute maximum ratings specify AVDD to AVSS ≤ +5.5 V and AVSS to DGND ≥ –2.8 V.