Texas Instruments ADS8865IDGS

Overview

ADS8865IDGS from Texas Instruments is a 16-bit, 400-kSPS true-differential SAR analog-to-digital converter with SPI-compatible serial interface, 96 dB SNR, ±1.0 LSB INL, and 2.6 mW power dissipation at full speed - deployed in precision medical instrumentation and low-power battery-operated data acquisition systems.

For engineers reviewing the ADS8865IDGS datasheet, ADS8865IDGS pinout, ADS8865IDGS application, or ADS8865IDGS equivalent, key selection criteria include true-differential input range (–VREF to +VREF), wide common-mode voltage support (0 V to VREF), no-latency output architecture, and daisy-chain SPI capability for multi-channel synchronization.

Technical Context

The ADS8865IDGS implements a charge-redistribution SAR architecture with integrated sample-and-hold, enabling single-cycle acquisition and conversion without pipeline latency. Its internal clock drives binary search logic across a capacitor DAC array referenced to an external 2.5–5 V source.

It supports three digital interface modes - 3-wire (CONVST as CS), 4-wire (DIN as CS), and daisy-chain - all synchronized to SCLK up to 16 MHz. A dedicated busy indicator bit option simplifies host timing coordination during high-throughput sampling.

Key Specifications

Pinout & Package

ADS8865IDGS is packaged in a 10-pin MSOP (DGS) with exposed thermal pad. Pin assignments are validated per TI SBAS573A datasheet Figure 10 and Table on page 9.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS8865IDGS, ADS8864IDGS trades 150 kSPS throughput for slightly lower power at mid-range speeds, while ADS8867IDGS sacrifices differential input and SNR to reduce system BOM cost - making ADS8865IDGS optimal for applications demanding both speed and true-differential fidelity.

Availability

ADS8865IDGS is available at Aetrix Electronics and suitable for precision medical equipment, industrial sensor interfaces, and battery-powered instrumentation requiring stable component supply and long-term production continuity.

Supply support for ADS8865IDGS 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 signal chain solutions.

The ADS8865IDGS belongs to TI's 16-bit SAR ADC family designed for high-accuracy, low-power, and space-constrained applications - emphasizing true-differential input flexibility, scalable power, and robust SPI interoperability.

FAQ

What is the maximum sample rate supported by the ADS8865IDGS?

The ADS8865IDGS supports a maximum throughput rate of 400 kSPS with no latency. This is confirmed in the Electrical Characteristics table (page 3) and Overview section (page 17) of the SBAS573A datasheet. At this rate, the device achieves 96 dB SNR and ±1.0 LSB INL while dissipating 2.6 mW. The conversion time is specified as 500–1300 ns, and acquisition time is fixed at 1200 ns.

Does the ADS8865IDGS require an external reference voltage?

Yes, the ADS8865IDGS requires an external reference voltage applied to the REF pin. It operates with a 2.5 V to 5 V reference, independent of AVDD and DVDD supplies. The reference must be decoupled with a ≥10 µF capacitor, and its value directly defines the full-scale differential input range (–VREF to +VREF). No internal reference is provided.

Can the ADS8865IDGS interface with a microcontroller using standard SPI?

Yes, the ADS8865IDGS features an SPI-compatible serial interface supporting 3-wire, 4-wire, and daisy-chain configurations. It uses standard SPI timing conventions (MSB-first, SCLK-synchronized DOUT), with CONVST or DIN acting as chip select depending on mode. No special protocol translation is needed - it works directly with MCU SPI peripherals.

What is the common-mode voltage range supported by the ADS8865IDGS analog inputs?

The ADS8865IDGS supports a common-mode voltage range of 0 V to VREF on its AINP and AINN pins. This is explicitly stated in the Description section (page 1) and Analog Input section (page 17), and enables direct interfacing with sensors whose common-mode output falls anywhere within that span - unlike many SAR ADCs constrained to VREF/2 ±10%.

Is the ADS8865IDGS pin-compatible with other devices in the ADS88xx family?

ADS8865IDGS shares the same 10-pin MSOP (DGS) package and pinout with ADS8864IDGS and ADS8867IDGS, as confirmed in TI's Package Option Addendum and pin configuration diagrams (page 9). However, functional differences exist - ADS8864IDGS is 250-kSPS, and ADS8867IDGS is single-ended - so electrical compatibility must be verified per application requirements.