Texas Instruments ADC121C021EVM

Overview

ADC121C021EVM from National Semiconductor is an evaluation board designed to accelerate prototyping and performance validation of the ADC121C021 family - I²C-compatible, 12-bit/10-bit/8-bit analog-to-digital converters with programmable alert output. It supports standalone logic analyzer testing or computer-based acquisition via WaveVision 4 software, features on-board LMP7731 input buffer and LM4050-4.1 precision reference, and ships pre-populated with the ADC121C021 (alert-option variant).

For engineers reviewing the ADC121C021EVM datasheet, ADC121C021EVM pinout, ADC121C021EVM application, or ADC121C021EVM equivalent, this page delivers verified hardware configuration details, jumper-controlled power/reference/analog-path options, I²C interface settings (100 kHz / 400 kHz / 3.4 MHz), dynamic performance measurement capabilities (SNR, SINAD, THD, SFDR, ENOB), and integration guidance for WaveVision 4-based system validation.

Technical Context

The ADC121C021EVM implements a complete signal chain for evaluating National's single-channel, I²C-compatible ADCs: analog input path supports DC-coupled, AC-coupled, or buffered (LMP7731 voltage follower/gain) configurations; reference selection includes external supply, WV4 board 3.3V/5.0V rails, or LM4050-4.1 shunt reference; and I²C bus control uses configurable pull-ups (JP2), series resistors (R2/R5), and direct SDA/SCL access points (VIA1/VIA2).

Functional operation spans two modes: Stand Alone mode enables direct I²C stimulus/response using external logic analyzers, while Computer mode integrates with the WaveVision 4 Data Capture Board (WV4) via J1 (14-pin WV4S connector) for automated register control, real-time FFT analysis, histogram generation, and dynamic parameter extraction - all requiring WaveVision 4 v4.4+ running on Windows.

Key Specifications

Availability

ADC121C021EVM is available at Aetrix Electronics and suitable for precision data acquisition validation, sensor interface development, and embedded ADC integration requiring stable component supply, traceable sourcing, and long-term design-in support.

Supply support for ADC121C021EVM 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; its legacy ADC and precision analog product lines continue under TI's portfolio with full documentation and support.

The ADC121C021EVM belongs to National's evaluation board family for the ADC121C02X series - designed specifically to simplify functional verification, dynamic performance characterization, and I²C register-level debugging of low-power, single-channel, resolution-flexible ADCs in industrial and instrumentation applications.

FAQ

What is the primary function of the ADC121C021EVM?

The ADC121C021EVM is a dedicated evaluation platform for the ADC121C021 family of I²C-compatible analog-to-digital converters. It enables rapid validation of conversion accuracy, alert functionality, automatic sampling modes, and dynamic performance metrics (SNR, THD, ENOB) - not a production-ready subsystem. The board ships pre-assembled with the ADC121C021 and supports both standalone logic analyzer use and WaveVision 4–driven PC-based analysis. ADC121C021EVM provides full access to all critical signals and configurable reference/input paths required for comprehensive ADC characterization.

Which ADC variants does the ADC121C021EVM support out of the box?

The ADC121C021EVM ships populated with the ADC121C021 (Alert Option), but its hardware and firmware support the full ADC121C02X family: ADC121C021/ADC101C021/ADC081C021 (Alert Option) and ADC121C027/ADC101C027/ADC081C027 (Address Option). For Address Option devices, users must order samples separately and manually replace U3; jumper JP5 and VIA5 enable correct I²C addressing (0x50–0x52 for ADCXX1C027, fixed 0x54 for ADCXX1C021). ADC121C021EVM's schematic and Bill of Materials are explicitly designed for cross-variant compatibility.

How do I configure the ADC121C021EVM for high-accuracy dynamic testing?

For high-accuracy dynamic testing, configure ADC121C021EVM with the LM4050-4.1 reference (short JP7 pins 1–2 and JP5 pins 7–8), use SMA-connected analog input (J2 footprint), install 51 Ω termination at R3 for 50 Ω sources, and select 3.4 MHz I²C speed in WaveVision 4. Ensure clean ±5 V supply to TP7 (300 mA limit), ground TP6, and verify VA = 4.1 V at VIA10. Dynamic source THD must exceed –90 dBc; FFT analysis in WaveVision 4 then reports SNR, SINAD, THD, SFDR, and ENOB directly. ADC121C021EVM's layout and decoupling (C3/C7/C4/C5) are optimized for this use case.

Can the ADC121C021EVM operate without the WaveVision 4 board?

Yes, ADC121C021EVM operates in Stand Alone mode without the WaveVision 4 board. Users drive SCL/SDA directly at J1 or solder wires to VIA1/VIA2, apply +5.0 V to TP7 (300 mA limit), ground TP6, set JP5 to pins 9–10, and monitor ALERT at VIA5 (for ADC121C021). I²C pull-ups are enabled via JP2. This mode requires external I²C master equipment (e.g., logic analyzer with pattern generator) for register reads/writes and data capture. ADC121C021EVM's hardware abstraction layer remains identical - only the control interface changes.

What are the key jumper functions on the ADC121C021EVM?

Key jumpers on ADC121C021EVM include: JP1 (input path: pins 1–2 = direct VIN, pins 2–3 = LMP7731 buffer); JP2 (I²C pull-ups: pins 1–2 = enabled); JP5 (VA source: pins 1–2 = 3.3 V from WV4, pins 3–4 = 5.0 V from WV4, pins 7–8 = LM4050-4.1, pins 9–10 = external VA_EXT); JP7 (LM4050 enable: pins 1–2 = active). These jumpers define analog signal integrity, reference stability, and interface compatibility - no soldering required for standard evaluation. ADC121C021EVM's User's Guide documents all 12 jumper configurations with functional impact.