Texas Instruments ADC081C02XEB

Overview

ADC081C02XEB from National Semiconductor is an evaluation board designed to accelerate prototyping and performance validation of the ADC081C021 - an I²C-compatible, 8-bit analog-to-digital converter with programmable alert output. It supports standalone logic analyzer testing or computer-based data capture via National's WaveVision 4 system, delivering real-time FFT analysis (SNR, SINAD, THD), histogram visualization, and register-level control of conversion timing and alert thresholds.

For engineers reviewing the ADC081C02XEB datasheet, ADC081C02XEB pinout, ADC081C02XEB application, or ADC081C02XEB equivalent, this board enables rapid verification of dynamic performance (≥90 dBc THD source requirement), I²C slave address configuration (0x54 for ALERT variant), alert threshold programming (VHIGH/VLOW registers), and analog input path options (DC/AC-coupled, buffered/unbuffered).

Technical Context

The ADC081C02XEB implements a complete signal chain: LMP7731 precision op-amp configured as voltage follower or gain stage, LM4050-4.1 shunt reference for stable VA supply, and configurable I²C pull-up resistors (2 kΩ) on SDA/SCL. It supports three power sources for VA: external +2.7V to +5.5V, WV4 board's 3.3V or 5.0V rails, or the onboard 4.1V reference.

Functional modes include Stand Alone (direct I²C stimulus via J1/VIA1/VIA2) and Computer Mode (WV4 interface via J1 header). Jumpers JP1–JP7 enable flexible analog input routing, reference selection, pull-up activation, and amplifier integration - all documented in schematic Figure 10 and Table 1 of the User's Guide.

Key Specifications

Availability

ADC081C02XEB is available at Aetrix Electronics and suitable for embedded sensor interface validation, industrial data acquisition system bring-up, and precision ADC performance benchmarking requiring stable component supply and full documentation support.

Supply support for ADC081C02XEB 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

National Semiconductor was a U.S.-based analog and mixed-signal semiconductor company, acquired by Texas Instruments in 2011. It specialized in high-performance data converters, power management, and interface ICs.

The ADC081C02XEB belongs to National's ADC121C021 family evaluation platform series, engineered specifically to de-risk design-in of low-power, I²C-based ADCs in space-constrained applications such as portable instrumentation and sensor nodes.

FAQ

What is the primary function of the ADC081C02XEB evaluation board?

The ADC081C02XEB evaluation board is a hardware platform designed exclusively to evaluate the ADC081C021 - an 8-bit, I²C-compatible analog-to-digital converter with alert functionality. It provides configurable analog input paths (DC/AC-coupled, buffered/unbuffered), selectable reference sources (including LM4050-4.1), and seamless integration with National's WaveVision 4 software for real-time FFT, histogram, and register-level diagnostics. The ADC081C02XEB itself is not a semiconductor device but a test tool for the ADC081C021.

Which ADC variant is pre-installed on the ADC081C02XEB board?

The ADC081C02XEB board ships with the ALERT-option variant: ADC081C021 (I²C address 0x54, ALERT pin functional). This is explicitly stated in Section 1.0 of the User's Guide: "The board comes stuffed with the ALERT option (ADCXX1C021)." To evaluate the ADDRESS-option variant (ADC081C027), users must order samples separately from national.com and manually replace U3.

Does the ADC081C02XEB support AC-coupled analog inputs?

Yes, the ADC081C02XEB supports AC-coupled analog inputs, but requires hardware modification: install 4.99 kΩ bias resistors at R1 and R4, replace C1 with a 1.0 µF capacitor, and optionally add a 51 Ω termination resistor at R3 for 50 Ω sources. These changes convert the default DC-coupled configuration (Figure 2) into the AC-coupled topology shown in Figure 3 of the User's Guide. SMA footprint J2 is recommended for high-fidelity dynamic testing.

What software is required to operate the ADC081C02XEB in Computer Mode?

WaveVision 4 software version 4.4 or higher is mandatory for Computer Mode operation of the ADC081C02XEB. It must be used with the WaveVision 4 Data Capture Board (WAVEVSN BRD 4.1 or later) connected via USB. The software provides register read/write access, automatic conversion mode setup, alert threshold configuration (VHIGH/VLOW), FFT analysis, and time-domain waveform display - all documented in Sections 5.0–5.3 of the User's Guide.

How is the analog supply voltage (VA) configured on the ADC081C02XEB?

VA is selected via jumper JP5: pins 1&2 for 3.3V (from WV4 board), pins 3&4 for 5.0V (from WV4 board), pins 7&8 for 4.1V (LM4050-4.1 shunt reference, enabled by shorting JP7 pins 1&2), or pins 9&10 for external supply at TP7. Section 4.7 specifies that National recommends the LM4050-4.1 for optimal ADC081C021 performance, and external VA must remain within +2.7V to +5.5V per the ADC081C021 datasheet.