Texas Instruments ADS1222IPWRG4

Overview

ADS1222IPWRG4 from Texas Instruments is a 2-channel, 24-bit delta-sigma analog-to-digital converter in TSSOP-14 package, delivering 20-bit effective resolution at 240 SPS with ±5V differential input range, 0.0015% max INL, and on-chip temperature sensor - deployed in portable medical equipment and industrial process control systems requiring high-precision, low-power signal acquisition.

For engineers reviewing the ADS1222IPWRG4 datasheet, ADS1222IPWRG4 pinout, ADS1222IPWRG4 application, or ADS1222IPWRG4 equivalent, this page delivers verified technical context, real-world design meaning of specifications, validated pin functions, confirmed alternative parts for similar high-resolution delta-sigma ADC applications, and supply support for volume procurement and BOM continuity.

Technical Context

The ADS1222IPWRG4 implements a delta-sigma (∆Σ) modulator with Sinc3 digital filter, supporting 24-bit no-missing-codes resolution and self-calibration. Its dual-differential-input multiplexer (AINP1/AINN1, AINP2/AINN2) is controlled by MUX and TEMPEN pins, enabling channel selection or on-chip temperature sensor activation.

Input buffering is pin-selectable via BUFEN, providing either 2.7 MΩ (buffer off) or 1.2 GΩ (buffer on) differential input impedance at 2 MHz clock. The 2-wire serial interface uses DRDY/DOUT for data-ready indication and MSB-first data output synchronized to SCLK, with CLK accepting up to 8 MHz external timing.

Key Specifications

Pinout & Package

TSSOP-14 (PW) package with 0.65 mm pitch, 5.0 mm × 4.4 mm footprint, and exposed pad not electrically connected - optimized for compact PCB layouts in space-constrained portable instrumentation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS1222IPWRG4, ADS1220IPWR trades temperature sensing for programmable gain and higher speed, while AD7792BRUZ offers SPI compatibility and extra channel at the cost of increased size and power - making ADS1222IPWRG4 optimal for compact, dual-channel, temperature-aware battery-powered systems.

Availability

ADS1222IPWRG4 is available at Aetrix Electronics and suitable for hand-held instrumentation, portable medical equipment, and industrial process control requiring stable component supply, long-term lifecycle support, and traceable sourcing for production programs.

Supply support for ADS1222IPWRG4 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 low-power design.

The ADS1222IPWRG4 belongs to TI's precision delta-sigma ADC product line, engineered specifically for high-accuracy, low-power measurement in portable and space-constrained industrial and medical systems.

FAQ

What is the maximum clock frequency supported by the ADS1222IPWRG4?

The ADS1222IPWRG4 supports a maximum CLK input frequency of 8 MHz, enabling data rates up to 240 SPS at 4 MHz and scaling linearly - for example, 120 SPS at 2 MHz. Exceeding 8 MHz violates absolute maximum ratings and may cause timing violations or conversion errors. The device's internal modulator sampling frequency is fCLK/32, so 8 MHz yields 250 kHz sampling, which directly determines noise shaping and settling behavior.

How does the BUFEN pin affect input impedance and measurement accuracy on the ADS1222IPWRG4?

When BUFEN is low, the ADS1222IPWRG4 uses switched-capacitor sampling, yielding 2.7 MΩ differential input impedance at 2 MHz CLK; when BUFEN is high, the chopper-stabilized buffer raises impedance to 1.2 GΩ. Higher impedance prevents loading of high-Z sources like thermocouples, reducing gain error match degradation from 100 µV to 20 µV and maintaining 0.0006% INL (typ) versus 0.0003% with buffer off.

Can the ADS1222IPWRG4 perform simultaneous sampling across both differential channels?

No - the ADS1222IPWRG4 uses a single delta-sigma modulator with time-multiplexed inputs; MUX selects either AINP1/AINN1 or AINP2/AINN2, so conversions occur sequentially, not simultaneously. However, channel switching is deterministic and fast: after toggling MUX, DRDY/DOUT remains high for 25.9–26.4 ms (at 2 MHz CLK) until fully settled data is ready, enabling tightly coordinated dual-channel acquisition in systems where inter-channel skew under 27 ms is acceptable.

What is the purpose of the TEMPEN pin on the ADS1222IPWRG4, and how is temperature data extracted?

The TEMPEN pin connects internal 1× and 64× scaled diodes to the input mux, replacing AINP/AINN with temperature-dependent voltage differences. At 25°C, the output is 106 mV with 360 µV/°C coefficient; reading this voltage via the ADC yields temperature with ±0.5°C typical accuracy. To use it, set TEMPEN = high and MUX = 0 or 1 - the device automatically routes the diode pair, and no external components are required beyond standard reference bypassing.

Does the ADS1222IPWRG4 require external voltage reference components?

No - the ADS1222IPWRG4 accepts an external differential reference via VREFP and VREFN pins, but does not include an internal reference. It supports reference voltages from 0.5 V to VDD, with optimal performance at VDD/2 (e.g., 2.5 V for 5 V supply). A 0.1 µF ceramic capacitor must be placed directly across VREFP–VREFN to suppress noise; failure to do so degrades INL and increases RMS noise beyond the specified 0.8 ppm of FSR.