Texas Instruments ADS8678EVM-PDK

Overview

ADS8678EVM-PDK from Texas Instruments is an evaluation module for the ADS8678 - an 8-channel, 14-bit, 500-kSPS SAR ADC with integrated analog front-end, ±20-V input overvoltage protection, and software-programmable bipolar/unipolar input ranges (±10.24 V to ±0.156 V). It enables rapid validation of high-precision data acquisition in industrial PLC analog input modules.

For engineers reviewing the ADS8678EVM-PDK datasheet, ADS8678EVM-PDK pinout, ADS8678EVM-PDK application, or ADS8678EVM-PDK equivalent, this module provides direct access to all ADC channels, SPI daisy-chain interface, ALARM output, auxiliary input, and configurable reference selection - supporting full characterization of channel-to-channel matching, gain/offset drift, SNR, and crosstalk under real-world signal conditions.

Technical Context

The ADS8678EVM-PDK implements the complete signal chain of the ADS8678 IC: eight independent analog input paths each with 1-MΩ constant-input-impedance PGA, 2nd-order LPF, OVP circuitry, and dedicated AIN_nP/AIN_nGND terminals. It routes all digital control signals (CS, SCLK, SDI, SDO, DAISY, REFSEL, RST/PD) to a standard 2×15-pin header compatible with TI's MCU LaunchPad™ and industry-standard logic analyzers.

Board-level design includes decoupling for AVDD/DVDD/REFCAP/REFIO per TI SBAS627 layout guidelines, 4.096-V internal reference support with REFCAP/REFGND/REFIO connections, and separate AGND/DGND/REFGND planes to preserve 85-dB SNR and ±0.25-LSB INL performance across –40°C to 125°C operation.

Key Specifications

Availability

ADS8678EVM-PDK is available at Aetrix Electronics and suitable for industrial automation, protection relay development, and PLC analog input module prototyping requiring stable component supply, traceable sourcing, and long-term evaluation hardware availability.

Supply support for ADS8678EVM-PDK 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications applications.

The ADS8678EVM-PDK belongs to TI's precision data acquisition evaluation platform family, designed specifically to accelerate validation of high-channel-count, high-accuracy SAR ADCs in harsh industrial environments with wide input voltage ranges and robust overvoltage protection.

FAQ

What is the ADS8678EVM-PDK used for?

The ADS8678EVM-PDK is an evaluation module that enables hardware and firmware validation of the ADS8678 8-channel, 14-bit, 500-kSPS SAR ADC. It provides full access to all analog inputs (AIN_0P through AIN_7P), auxiliary input (AUX_IN), SPI interface signals (CS, SCLK, SDI, SDO, DAISY), ALARM output, and reference configuration (REFSEL/REFIO/REFCAP). Engineers use the ADS8678EVM-PDK to verify dynamic performance (SNR, THD, SINAD), channel matching, input range flexibility, and overvoltage protection behavior before integrating the ADS8678 into final systems.

Does the ADS8678EVM-PDK include the ADS8678 IC?

Yes, the ADS8678EVM-PDK ships with a populated ADS8678IC (TSSOP-38 package) pre-mounted on the board. The module is fully assembled and tested, including all required decoupling capacitors, reference circuitry, and ground plane segmentation per TI SBAS627 layout recommendations. No additional soldering or component placement is needed to begin evaluating the ADS8678 functionality.

Can the ADS8678EVM-PDK support daisy-chaining multiple ADS8678 devices?

Yes, the ADS8678EVM-PDK supports daisy-chaining via the DAISY pin and standard SPI interface. The board exposes DAISY as a dedicated header pin and routes SDO→SDI between adjacent positions, enabling multi-device synchronization without external wiring. This allows users to validate timing-critical aggregate throughput (up to 500 kSPS per device) and register-level control across cascaded ADS8678 units using a single host controller.

What input voltage ranges can be tested using the ADS8678EVM-PDK?

The ADS8678EVM-PDK supports all input ranges defined for the ADS8678 IC: bipolar options (±10.24 V, ±5.12 V, ±2.56 V, ±1.28 V, ±0.64 V, ±0.3125 V, ±0.15625 V) and unipolar options (0–10.24 V, 0–5.12 V, 0–2.56 V, 0–1.28 V, 0–0.64 V, 0–0.3125 V, 0–0.15625 V). Each channel's range is independently programmable in software, and the EVM provides test points and jumpers to apply calibrated signals across these full spans while maintaining 1-MΩ input impedance.

Is the internal 4.096-V reference enabled by default on the ADS8678EVM-PDK?

Yes, the ADS8678EVM-PDK configures REFSEL low by default, enabling the internal 4.096-V reference and driving it onto the REFIO pin. The board includes a 22-µF tantalum capacitor on REFCAP and proper decoupling to REFGND, meeting TI's specification for <20 ppm/°C drift and 15-ms turn-on time. Users may disable the internal reference and apply an external source by lifting the REFSEL jumper and connecting to REFIO.