Texas Instruments ADS125H02EVM

Overview

ADS125H02EVM from Texas Instruments is an evaluation module kit designed to support hardware and software validation of the ADS125H02, a 2-channel, 24-bit, 40-kSPS delta-sigma ADC with integrated ±18-V programmable gain amplifier (PGA), 1-GΩ input impedance, on-chip voltage reference, CRC error detection, and signal monitoring features - used in high-precision industrial sensor interface and weigh-scale applications.

For engineers reviewing the ADS125H02EVM datasheet, ADS125H02EVM pinout, ADS125H02EVM application, or ADS125H02EVM equivalent, this page delivers verified technical context, key specifications, USB-powered operation details, SPI-based host communication architecture, and supported Windows GUI functionality for register-level device control and real-time data acquisition.

Technical Context

The ADS125H02EVM integrates the TM4C1294NCPDT microcontroller to manage SPI communication with the ADS125H02 ADC, enabling register read/write, conversion control, calibration, and CRC-enabled data transfer over USB 2.0. It supports both onboard ±15-V HV supply generation from USB and external ±15-V analog supply via J4 terminal block.

Hardware features include configurable analog input headers (J1–J3) with RC-filtered AIN0/AIN1, REFOUT, REFP/REFN pairs, IDAC outputs, and fault LED indication; digital interface (J5) exposes all critical SPI signals (nCS1/nCS2, SCLK, DIN/DOUT, nDRDY, START, nRESET), GPIOs, and level-shifter voltages tied to the Tiva processor.

Key Specifications

Availability

ADS125H02EVM is available at Aetrix Electronics and suitable for precision sensor interface evaluation, industrial weigh-scale system prototyping, and high-voltage analog front-end development requiring stable component supply and full toolchain integration.

Supply support for ADS125H02EVM 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 specializing in analog, embedded processing, and power management technologies, with leadership in precision data converters and industrial interface solutions.

The ADS125H02EVM belongs to TI's precision delta-sigma ADC evaluation platform family, engineered to accelerate design-in of high-resolution, high-input-impedance sensor signal chains for industrial automation, test equipment, and structural monitoring systems.

FAQ

What is the primary function of the ADS125H02EVM?

The ADS125H02EVM is an evaluation module that enables hardware and software validation of the ADS125H02 24-bit delta-sigma ADC. It provides complete signal chain access - including analog inputs, PGA configuration, reference selection, IDAC excitation, and SPI register control - through a Windows GUI powered by the TM4C1294NCPDT microcontroller. The ADS125H02EVM supports both USB-derived and external high-voltage supplies for flexible lab and benchtop testing.

Does the ADS125H02EVM require external power, or is it USB-powered?

The ADS125H02EVM operates primarily from a standard USB 2.0 connection, which powers the onboard 5-V AVDD, 3.3-V DVDD, and ±15-V high-voltage analog supplies. An external ±15-V supply can be connected via terminal block J4 when switch S1 is set to the left position - useful for noise-sensitive or high-current evaluation scenarios. No external power is required for basic operation, but the onboard HV supply is not pre-populated and must be enabled per jumper JP7 configuration.

Which software is required to operate the ADS125H02EVM?

Two software components are required: the Delta-Sigma ADC Evaluation Software (GUI installer) and the ADS125H02-specific device package. Both are downloaded from ti.com/tool/ADS125H02EVM. The GUI runs on Windows 7 or later and communicates with the ADS125H02EVM over USB CDC. It provides register-level control, real-time data collection, offset/system calibration, and CRC-aware SPI transaction logging - all validated for use with the ADS125H02EVM hardware revision documented in SBAU318A.

How does the ADS125H02EVM interface with the ADS125H02 ADC?

The ADS125H02EVM interfaces with the ADS125H02 ADC via a dedicated SPI bus routed through level shifters (U5–U7) to the TM4C1294NCPDT microcontroller. Critical signals include ADC_nCS1/ADC_nCS2, ADC_SCLK, ADC_MOSI/DIN, ADC_MISO/DOUT, ADC_nDRDY, ADC_START, and ADC_nRESET. The microcontroller handles command translation, timing synchronization, and fault reporting - ensuring robust, CRC-verified communication as defined in the ADS125H02 datasheet SBAS790 and ADS125H02EVM User's Guide SBAU318A.

Can the ADS125H02EVM support external clock sources for the ADS125H02?

Yes - the ADS125H02EVM supports external clocking via connector J5, which connects directly to the ADS125H02 CLKIN pin (Pin 42). A 7.3728-MHz clock is recommended for general operation; 10.24 MHz is required only for 40-kSPS mode. Before applying an external clock, the GUI must issue the HOLDCLOCK 0 command to release the Tiva microcontroller's GPIO-driven low state on CLKIN. This ensures the ADS125H02 uses the external source instead of its internal oscillator - a capability fully documented and tested in the ADS125H02EVM User's Guide.