Texas Instruments ADS8668EVM-PDK

Overview

ADS8668EVM-PDK from Texas Instruments is an evaluation module for the ADS8668 8-channel, 12-bit, 500-kSPS SAR ADC with integrated analog front-end, ±20-V input overvoltage protection, 1-MΩ constant input impedance, 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 ADS8668EVM-PDK datasheet, ADS8668EVM-PDK setup guide, ADS8668EVM-PDK interface configuration, or ADS8668EVM-PDK compatibility with ADS8668-based systems, this module provides full hardware access to all ADC channels, SPI daisy-chain capability, ALARM output, AUX input, and on-board 4.096-V reference - supporting immediate functional verification and system-level timing analysis.

Technical Context

The ADS8668EVM-PDK implements a complete signal chain for the ADS8668 IC, including precision decoupling networks for AVDD/DVDD/REFCAP/REFIO, low-inductance AGND/DGND separation, and buffered analog input paths with OVP-enabled front-end circuitry per channel. It supports both manual and auto-scan multiplexer modes via configurable jumpers and firmware.

Designed for direct connection to host microcontrollers or FPGAs, the board features a standard 0.1"-spaced header for SPI signals (CS, SCLK, SDI, SDO), DAISY, RST/PD, REFSEL, ALARM, and all eight AIN_nP/AIN_nGND pairs plus AUX_IN/AUX_GND. All critical timing parameters - tCONV = 850 ns, tACQ = 1150 ns, fSCLK ≤ 17 MHz - are preserved per ADS8668 specification.

Key Specifications

Availability

ADS8668EVM-PDK is available at Aetrix Electronics and suitable for industrial PLC analog input modules, protection relay development, power automation test benches, and embedded data acquisition systems requiring stable component supply and rapid prototyping capability.

Supply support for ADS8668EVM-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 precision data converters, power management, and industrial interface technologies.

The ADS8668EVM-PDK belongs to TI's precision data acquisition evaluation platform family, designed specifically to accelerate development of high-reliability, wide-input-range industrial measurement systems using the ADS866x series of integrated SAR ADCs.

FAQ

What is the primary function of the ADS8668EVM-PDK?

The ADS8668EVM-PDK is an evaluation module that provides a complete, ready-to-use hardware platform for testing and validating the ADS8668 8-channel, 12-bit, 500-kSPS SAR ADC. It exposes all critical signals - including all eight analog inputs, SPI interface, ALARM output, AUX channel, and reference control - enabling immediate functional verification, timing analysis, and system integration without custom PCB design. The ADS8668EVM-PDK directly supports the full electrical and thermal specifications of the ADS8668 IC.

Does the ADS8668EVM-PDK support daisy-chaining multiple ADS8668 devices?

Yes, the ADS8668EVM-PDK includes dedicated routing for the DAISY signal and full SPI interface (CS, SCLK, SDI, SDO), enabling seamless daisy-chain configuration of multiple ADS8668 devices as specified in the ADS8668 datasheet. The board's layout preserves required timing margins (tSU_DSYCK ≥ 5 ns, tHT_CKDSY ≥ 5 ns) and provides test points for signal integrity validation during multi-device operation. This capability is fully operational when using the ADS8668EVM-PDK with compatible host controllers.

Can the ADS8668EVM-PDK be used with external reference sources?

Yes, the ADS8668EVM-PDK supports both internal and external reference configurations. When REFSEL is pulled high, the REFIO pin becomes an input, allowing connection of an external 4.046–4.146-V reference source. The board includes appropriate decoupling pads and routing for external reference stability, maintaining the ADS8668's specified gain error matching (±0.1%FSR) and SNR (≥71.4 dB) under external reference operation. This functionality is fully implemented and tested on the ADS8668EVM-PDK.

What analog input protection does the ADS8668EVM-PDK provide?

The ADS8668EVM-PDK implements the full ±20-V input overvoltage protection (OVP) capability of the ADS8668 IC across all eight analog input channels (AIN_0P–AIN_7P), as defined in the ADS8668 absolute maximum ratings. Each channel includes discrete OVP circuitry referenced to AVDD, ensuring robustness against field transients while preserving the 1-MΩ constant input impedance and channel-independent programmable gain. This protection is active and verified per ADS8668EVM-PDK design documentation.

Is the AUX input channel accessible on the ADS8668EVM-PDK?

Yes, the ADS8668EVM-PDK provides full access to the AUX_IN and AUX_GND pins of the ADS8668 via screw-terminal connections, enabling independent auxiliary measurement capability with 12-bit resolution, ±0.2 LSB DNL, and 73.2-dB SNR as specified for the AUX channel. The board routes these signals with matched impedance and proper decoupling, supporting its use for bias monitoring, temperature sensor interfacing, or secondary signal acquisition alongside main channel sampling. This feature is physically present and electrically validated on the ADS8668EVM-PDK.