Texas Instruments ADS1224IPWR

Overview

ADS1224IPWR from Texas Instruments is a 24-bit, delta-sigma analog-to-digital converter with four differential input channels, ±5V differential input range, 0.0015% max INL, 120 SPS data rate at 2 MHz clock, and integrated temperature sensor. It operates from 2.7V to 5.5V analog/digital supplies and delivers 300 µA typical current consumption in normal mode - ideal for high-precision portable instrumentation requiring low power and space-constrained PCB layouts.

For engineers reviewing the ADS1224IPWR datasheet, ADS1224IPWR pinout, ADS1224IPWR application, or ADS1224IPWR equivalent, this page provides verified technical context, TSSOP-20 package mapping, real-world use scenarios in weigh scales and medical devices, and two validated alternative parts with documented functional and application-level differences.

Technical Context

The ADS1224IPWR implements a Sinc3 digital filter following a delta-sigma modulator, delivering 24-bit no-missing-codes resolution with 0.8 ppm rms noise. Its 4-channel input multiplexer (controlled by MUX0/MUX1) supports selectable differential inputs and on-chip temperature sensing via TEMPEN activation.

Pin-selectable chopper-stabilized input buffer enables 1.2 GΩ differential input impedance (at 2 MHz clock), while buffer-off operation yields 2.7 MΩ. The 2-wire serial interface uses DRDY/DOUT for data-ready signaling and MSB-first data output synchronized to SCLK, with self-calibration triggered by extra SCLK pulses after data read.

Key Specifications

Pinout & Package

TSSOP-20 package (PW designation), 0.65 mm pitch, 6.5 mm × 4.4 mm body size, exposed pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS1224IPWR, ADS1220IPWR offers higher speed and integrated PGA but sacrifices temperature sensing and 2-wire simplicity; AD7792BRUZ provides superior noise performance and internal reference but lacks hardware-selectable buffering and demands external signal conditioning for high-impedance sensors.

Availability

ADS1224IPWR 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.

Supply support for ADS1224IPWR 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 low-power design.

The ADS1224IPWR belongs to TI's precision delta-sigma ADC product line, engineered specifically for high-resolution, low-power measurement in portable and space-constrained industrial systems.

FAQ

What is the maximum clock frequency supported by the ADS1224IPWR?

The ADS1224IPWR supports a maximum CLK input frequency of 8 MHz, enabling up to 240 SPS data rate. At 8 MHz, the modulator sampling frequency becomes 250 kHz, and the Sinc3 filter's −3 dB cutoff shifts to 125 Hz. Operation above 8 MHz risks timing violations and degraded INL performance, as confirmed in the Absolute Maximum Ratings and Electrical Characteristics sections of the SBAS286C datasheet.

Does the ADS1224IPWR require an external reference voltage?

Yes, the ADS1224IPWR requires an external differential reference applied across VREFP and VREFN pins. It does not include an internal voltage reference. The reference voltage range is 0.5 V to AVDD, with optimal performance achieved when VREF = AVDD/2. A 0.1 µF ceramic capacitor must be placed directly between VREFP and VREFN for stability, as specified in the Voltage Reference Inputs section of the SBAS286C datasheet.

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

When BUFEN is high, the ADS1224IPWR activates a chopper-stabilized buffer, raising differential input impedance to 1.2 GΩ (at 2 MHz CLK) and reducing offset drift to 0.2 µV/°C. When BUFEN is low, input impedance drops to 2.7 MΩ and INL improves slightly (0.0015% vs. 0.0006% typ), but high-Z sources may load the input. The choice directly impacts sensor compatibility and thermal drift - critical for RTD or thermocouple applications.

Can multiple ADS1224IPWR devices share a single CLK signal for synchronized sampling?

Yes, multiple ADS1224IPWR devices can share a common CLK signal to achieve synchronous sampling across channels. The datasheet explicitly states that "Multiple ADS1224s can be connected together to create a synchronously sampling multichannel measurement system." All devices must use identical CLK frequency and phase; DRDY/DOUT and SCLK lines remain independent per device to avoid bus contention.

What is the purpose of the TEMPEN pin and how is temperature data retrieved?

The TEMPEN pin selects the on-chip temperature sensor instead of analog input channels. When TEMPEN = high, the internal multiplexer routes two scaled diodes (1× and 64×) to the ADC front-end. The resulting voltage difference - 106 mV at 25°C with 360 µV/°C coefficient - is digitized as a standard 24-bit conversion. Temperature data is retrieved identically to analog channel data via DRDY/DOUT and SCLK, requiring no special command sequence beyond asserting TEMPEN before conversion start.