Texas Instruments ADS8688AEVM-PDK

Overview

ADS8688AEVM-PDK from Texas Instruments is an evaluation module for the ADS8688A 8-channel, 16-bit, 500-kSPS SAR ADC with integrated analog front-end, ±20-V input overvoltage protection, and programmable bipolar/unipolar input ranges up to ±10.24 V. It supports industrial PLC analog input modules and protection relay systems requiring high-precision, channel-independent gain/offset calibration.

For engineers reviewing the ADS8688AEVM-PDK datasheet, ADS8688AEVM-PDK pinout, ADS8688AEVM-PDK application, or ADS8688AEVM-PDK equivalent, this module enables rapid validation of the ADS8688A's daisy-chain SPI interface, ALARM thresholding, AUX input routing, and 1-MΩ constant-input-impedance performance across –40°C to 125°C.

Technical Context

The ADS8688AEVM-PDK implements a complete signal chain test platform for the ADS8688A, including precision decoupling for AVDD/DVDD/REFIO/REFCAP, low-inductance AGND/DGND separation, and configurable jumper-based selection of internal (4.096 V) or external reference sources. It routes all 38 TSSOP pins-including AIN_0P through AIN_7P, DAISY, ALARM, and REFSEL-to accessible test points and headers.

Designed for functional verification of multiplexed acquisition modes (auto/manual scan), per-channel programmable input ranges (±10.24 V to ±0.156 V), and auxiliary channel direct connection, the EVM provides on-board op-amp buffering for AUX_IN and calibrated voltage dividers for ALARM threshold setup, aligning with TI's SBAS680 design guidelines.

Key Specifications

Availability

ADS8688AEVM-PDK is available at Aetrix Electronics and suitable for industrial PLC analog input modules, power automation systems, and protection relay development requiring stable component supply and fast-turn evaluation hardware.

Supply support for ADS8688AEVM-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 delivering analog and embedded processing solutions, with leadership in data converters, power management, and industrial interface ICs.

The ADS8688AEVM-PDK belongs to TI's precision data acquisition evaluation platform family, designed specifically to accelerate prototyping and validation of high-channel-count, high-voltage-tolerant SAR ADCs in harsh industrial environments.

FAQ

What is the primary function of the ADS8688AEVM-PDK?

The ADS8688AEVM-PDK is an evaluation module that enables hardware and firmware validation of the ADS8688A 8-channel, 16-bit SAR ADC. It provides full access to all analog inputs, digital interface signals, reference options, and alarm functionality-allowing engineers to verify channel-to-channel matching, daisy-chain timing, overvoltage protection behavior, and programmable input range configuration before system integration.

Does the ADS8688AEVM-PDK support both internal and external reference configurations?

Yes, the ADS8688AEVM-PDK supports both reference modes. When REFSEL is pulled low, the ADS8688A uses its internal 4.096-V reference, and REFIO becomes an output. When REFSEL is high, REFIO accepts an external reference voltage (4.046 V to 4.146 V), enabling system-level reference synchronization. The EVM includes jumpers and test points to configure either mode without soldering.

Can the ADS8688AEVM-PDK be used to evaluate daisy-chain SPI operation with multiple ADS8688A devices?

Yes, the ADS8688AEVM-PDK exposes the DAISY, CS, SCLK, SDI, and SDO pins with proper termination and signal integrity layout. Its design follows TI's SBAS680 daisy-chain timing requirements (tSU_DSYCK = 5 ns, tHT_CKDSY = 5 ns), allowing direct connection to additional ADS8688AEVM-PDK units or custom boards to validate multi-device serial acquisition and synchronized sampling.

How does the ADS8688AEVM-PDK handle input overvoltage protection testing?

The ADS8688AEVM-PDK maintains the ADS8688A's native ±20-V overvoltage protection on all AIN_nP and AIN_nGND pins when AVDD = 5 V and source impedance < 30 kΩ. Test points are provided for injecting fault voltages, and the board's ground isolation prevents coupling into DVDD/AGND domains-enabling safe validation of OVP clamp behavior and recovery timing per the device's absolute maximum ratings.

Is the AUX input channel accessible and conditioned on the ADS8688AEVM-PDK?

Yes, the AUX_IN and AUX_GND pins are fully routed to screw terminals and test points on the ADS8688AEVM-PDK. The board includes optional RC filtering and a dedicated op-amp buffer stage to preserve signal integrity, supporting direct connection of sensors or external references while maintaining the ADS8688A's specified AUX channel performance: 16-bit resolution, 87–89 dB SNR, and ±0.2% FSR gain error.