Texas Instruments ADS1220IPW

Overview

ADS1220IPW from Texas Instruments is a 24-bit, low-power, precision delta-sigma ADC with integrated PGA (gain up to 128), dual programmable current sources (10 µA–1.5 mA), internal 2.048 V reference (5 ppm/°C drift), and SPI interface. It supports two differential or four single-ended inputs and delivers up to 20 bits effective resolution at 20 SPS with simultaneous 50/60 Hz rejection-ideal for RTD, thermocouple, and bridge sensor signal conditioning in industrial field transmitters.

For engineers reviewing the ADS1220IPW datasheet, ADS1220IPW pinout, ADS1220IPW application, or ADS1220IPW equivalent, key selection criteria include its duty-cycle mode power consumption (120 µA typ), integrated temperature sensor (±0.5 °C accuracy), programmable data rates up to 2 kSPS, and TSSOP-16 package compatibility with space-constrained analog input modules.

Technical Context

The ADS1220IPW implements a 24-bit delta-sigma modulator with a single-cycle settling digital filter optimized for industrial noise environments. Its flexible MUX enables configurable input topologies-including pseudo-differential and fully differential modes-with or without PGA engagement.

Internal resources include dual matched IDACs for 3-/4-wire RTD excitation, a low-drift internal reference, and a system monitor featuring a precision temperature sensor (14-bit resolution, 0.03125 °C step) and low-side power switch (RON = 5.5 Ω). All functions are controlled via SPI Mode 1 with DRDY/DOUT multiplexing.

Key Specifications

Pinout & Package

The ADS1220IPW is packaged in a 16-pin TSSOP (PW) measuring 5.0 mm × 6.4 mm, with exposed thermal pad not connected. Pin functions are validated per TI SBAS501D Rev. May 2026.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision ADC applications.

Compared with ADS122U04IPW, the ADS1220IPW offers deterministic SPI timing control essential for synchronized multi-device acquisition; versus ADS1120IPW, it delivers 8 additional bits of resolution enabling sub-µV signal detection in high-gain sensor interfaces-justifying its use in metrology-grade field transmitters.

Availability

ADS1220IPW is available at Aetrix Electronics and suitable for industrial field transmitters, PLC analog input modules, and patient monitoring systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADS1220IPW 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 conversion and industrial signal chain solutions.

The ADS1220 product line targets high-accuracy sensor measurement in space- and power-constrained industrial and medical systems, integrating critical analog functions to reduce system complexity and improve long-term reliability.

FAQ

What is the maximum achievable effective resolution of the ADS1220IPW at 20 SPS?

The ADS1220IPW achieves up to 20 bits effective resolution at 20 SPS with simultaneous 50/60 Hz rejection. This is measured under standard conditions (AVDD = 3.3 V, PGA enabled, external 2.5 V reference) and reflects RMS noise performance after digital filtering. The 24-bit architecture ensures no missing codes across the full range, but effective resolution is limited by thermal and quantization noise at higher data rates. For the ADS1220IPW, this 20-bit ENOB enables precise digitization of microvolt-level thermocouple outputs without external amplification.

Does the ADS1220IPW support bipolar analog supplies?

Yes, the ADS1220IPW supports bipolar analog supplies with AVDD to DGND ranging from 2.3 V to 2.75 V and AVSS to DGND from –2.75 V to –2.3 V. This configuration allows true bipolar input signal measurement (e.g., ±100 mV from a load cell) while maintaining specified performance. The device's absolute maximum ratings permit AVSS down to –2.8 V, and the internal PGA remains functional across the full bipolar operating range. When using bipolar supplies, the ADS1220IPW maintains its 24-bit no-missing-codes guarantee and specified INL of ±6 ppmFSR.

How does the internal temperature sensor in the ADS1220IPW improve thermocouple measurement accuracy?

The internal temperature sensor in the ADS1220IPW provides cold-junction compensation (CJC) with ±0.5 °C accuracy from –40°C to +125°C, directly correcting for thermocouple reference junction temperature variations. It operates independently of the main ADC channel and delivers 14-bit resolution (0.03125 °C step size), enabling precise offset correction in real time. Because the sensor is monolithically integrated, its thermal coupling to the analog front-end minimizes thermal lag and gradient errors. In a K-type thermocouple system, this translates to <±1.2 °C total measurement uncertainty-meeting IEC 61511 functional safety requirements for process instrumentation. The ADS1220IPW uses this sensor automatically during CJC-enabled conversions.

Can the ADS1220IPW operate without an external crystal or clock source?

Yes, the ADS1220IPW includes an internal oscillator accurate to ±1% over temperature and supply, eliminating the need for external timing components. When CLK is tied to DGND, the device defaults to internal clock operation at 256 kHz (normal/duty-cycle mode) or 512 kHz (turbo mode). This oscillator drives both the modulator and SPI interface timing, ensuring full functionality-including simultaneous 50/60 Hz rejection at 20 SPS and all programmable data rates-without external dependencies. The ADS1220IPW's internal clock meets timing specifications for SPI Mode 1 communication and supports all register configurations and conversion modes documented in SBAS501D.

What are the recommended decoupling practices for the ADS1220IPW's AVDD and DVDD supplies?

TI specifies a minimum 100 nF ceramic capacitor from AVDD to AVSS and from DVDD to DGND, placed as close as possible to the respective pins. For high-precision applications, a parallel combination of 100 nF (X7R) and 10 µF (tantalum or X5R) is recommended to suppress both high-frequency switching noise and low-frequency supply ripple. AVDD and DVDD must be supplied from independent low-noise LDOs or filtered rails; shared supply paths introduce PSRR degradation, especially at 50/60 Hz. Ground planes should be solid and split only between AVSS and DGND beneath the ADS1220IPW, with a single-point connection near the device. These practices ensure the ADS1220IPW maintains its specified 105 dB NMRR and 115 dB CMRR performance.