Texas Instruments ADS8331IPW

Overview

ADS8331IPW from Texas Instruments is a low-power, 16-bit, 500-kSPS successive approximation register (SAR) analog-to-digital converter with integrated 4-channel unipolar multiplexer, on-chip conversion clock, and SPI/DSP-compatible serial interface. It operates from 2.7 V to 5.5 V analog supply, achieves ±1.2 LSB typical INL and 91.5 dB SNR at 1 kHz, and targets precision data acquisition in space-constrained industrial systems.

For engineers reviewing the ADS8331IPW datasheet, ADS8331IPW pinout, ADS8331IPW application, or ADS8331IPW equivalent, key selection considerations include its 4-channel mux architecture, 24-pin TSSOP package, unipolar input range up to 2.5 V (or 4.096 V), deep power-down mode (50 nA), and daisy-chain capability for multi-ADC synchronization.

Technical Context

The ADS8331IPW implements a capacitor-based SAR ADC core with inherent sample-and-hold, supporting both manual and auto-triggered conversions via CONVST or global CONVST. Its internal 11.5 MHz conversion clock eliminates external timing components, while programmable EOC/INT polarity and status reporting enable flexible host interrupt handling.

It features dual-supply operation: VA (2.7–5.5 V) powers analog circuitry including the mux and reference input, while VBD (1.65–VA) supplies digital I/O with CMOS-level compatibility. The device supports daisy-chain mode using SDO/CDI pins and offers three powerdown modes-Deep, Nap, and Auto-NAP-with current draw as low as 50 nA in Deep PD.

Key Specifications

Pinout & Package

ADS8331IPW is housed in a 24-pin TSSOP (PW) package with exposed thermal pad connected to AGND. Pin functions are fully defined per TI SBAS363E datasheet Rev E (August 2016).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit SAR ADC applications.

Compared with ADS8331IPW, ADS8327IPW adds two more mux channels but removes daisy-chain capability, while AD7682BCPZ trades speed and configurability for compact size and integrated reference-making ADS8331IPW the only option supporting 500-kSPS synchronized multi-device acquisition in TSSOP.

Availability

ADS8331IPW is available at Aetrix Electronics and suitable for industrial process controls, medical instrumentation, and automated test equipment requiring stable component supply and long-term manufacturability.

Supply support for ADS8331IPW 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, embedded processing, and connectivity technologies with decades of precision data converter innovation.

The ADS8331IPW belongs to TI's low-power, high-speed SAR ADC family designed specifically for high-resolution, multi-channel data acquisition in space- and power-constrained industrial and medical systems.

FAQ

What is the maximum sampling rate supported by the ADS8331IPW?

The ADS8331IPW supports a maximum throughput rate of 500 kSPS under specified operating conditions (TA = –40°C to +85°C, VA = 2.7 V to 5.5 V). This rate is sustained with full 16-bit accuracy, 18-cycle conversion time, and valid timing margins per SBAS363E Rev E. At 500 kSPS, the device consumes 14.2 mW at VA = 2.7 V and VBD = 1.65 V. The ADS8331IPW maintains this performance across its full industrial temperature range without derating.

Does the ADS8331IPW require an external clock source for conversion?

No, the ADS8331IPW does not require an external clock source for conversion. It integrates an internal conversion clock (CCLK) operating at 10.5–12.6 MHz (depending on VA), which drives the SAR logic and sample-and-hold automatically. An external SCLK is only needed for the SPI interface. When SCLK is used for both I/O and conversion timing, its frequency must be ≤21 MHz. The ADS8331IPW remains fully functional with SCLK disabled during conversion if internal CCLK is enabled.

What are the power supply requirements for the ADS8331IPW?

The ADS8331IPW requires two independent supplies: VA (analog supply, 2.7 V to 5.5 V) and VBD (digital I/O supply, 1.65 V to VA). VA powers the ADC core, mux, and reference input; VBD powers the SPI interface and logic. Both supplies must be well-decoupled, and AGND and DGND should connect at a single point near the device. The ADS8331IPW draws 5.2–6.5 mA from VA and 0.1–0.4 mA from VBD at 500 kSPS, with Deep PD current as low as 50 nA.

Can the ADS8331IPW interface directly with a 1.8-V microcontroller?

Yes, the ADS8331IPW can interface directly with a 1.8-V microcontroller by setting VBD = 1.8 V. Its digital I/O pins (SDI, SDO, FS/CS, SCLK, CONVST, RESET, EOC/INT/CDI) are CMOS-compatible and support VIH ≥0.8 × VBD and VIL ≤0.1 × VBD at VBD = 1.65–2.5 V. VOH and VOL specifications guarantee rail-to-rail logic levels at 1.8 V, and SCLK may run up to 25 MHz in I/O-only mode. No level-shifting circuitry is required when VBD = 1.8 V and VA is independently set to 2.7–5.5 V.

What is the function of the COM pin on the ADS8331IPW?

On the ADS8331IPW, the COM pin serves as the common-mode reference for all four analog inputs (IN0–IN3) and the ADCIN pin. It defines the lower bound of the unipolar input range (e.g., 0 V when tied to AGND) and must be connected to a low-impedance analog ground node-ideally through a dedicated via-to prevent noise coupling and maintain DC accuracy. The COM pin is not internally connected to AGND; improper routing causes gain/offset errors and degraded INL. Its voltage range is limited to AGND ±0.2 V per absolute maximum ratings.