Texas Instruments ADC122S021EVAL

Overview

ADC122S021EVAL from National Semiconductor is an evaluation board designed to support rapid performance characterization of the ADC122S021 - a 12-bit, dual-channel, serial-output SAR analog-to-digital converter with internal input multiplexer and programmable sampling rate up to 200 kSPS. It enables dynamic testing (SNR, SINAD, THD, SFDR, ENOB) using WaveVision4 software and hardware, and supports both AC- and DC-coupled analog inputs via BNC1/BNC2.

For engineers reviewing the ADC122S021EVAL datasheet, ADC122S021EVAL pinout, ADC122S021EVAL application, or ADC122S021EVAL equivalent, this board provides standardized signal conditioning, adjustable DUT supply (2.7V–5.0V), configurable clock sourcing (1–20 MHz), and direct interface to logic analyzers or WaveVision4 capture hardware - critical for validating high-fidelity data acquisition in test instrumentation and sensor interface designs.

Technical Context

The ADC122S021EVAL board interfaces exclusively with the ADC122S021 (MSOP-8 package), supporting its 2-channel, single-ended analog input architecture and SPI-compatible serial interface. It implements user-adjustable input bias (via VR2), on-board reference derived from DUT supply voltage, and selectable coupling (AC/DC) per channel using JP1 and JP3 jumpers.

Signal integrity is maintained through 50 Ω impedance-matched BNC inputs, coherent sampling support via synchronized signal/clock sources, and dedicated test points (TP1–TP8) for real-time monitoring of supply, clock, and digital I/O signals. Power delivery is simplified via a single +5.5V to +5.7V input at P1, supplying both the board and the WaveVision4 capture board through diode-isolated routing.

Key Specifications

Availability

ADC122S021EVAL is available at Aetrix Electronics and suitable for test instrumentation development, sensor signal chain validation, and high-accuracy data acquisition system prototyping requiring stable component supply and traceable evaluation infrastructure.

Supply support for ADC122S021EVAL 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 semiconductor company specializing in analog and mixed-signal ICs, acquired by Texas Instruments in 2011. Its legacy evaluation platforms remain widely used in precision data conversion applications.

The ADC122S021EVAL belongs to National's ADCxx2Sxx1 family evaluation platform series, engineered specifically to accelerate design-in of low-power, multi-channel SAR ADCs in measurement, industrial sensing, and portable instrumentation systems.

FAQ

What is the primary function of the ADC122S021EVAL evaluation board?

The ADC122S021EVAL evaluation board is a dedicated hardware platform for evaluating the ADC122S021 - a 12-bit, dual-input, serial-output SAR analog-to-digital converter. It provides signal conditioning, adjustable power and bias, clock flexibility, and digital interface access to enable comprehensive dynamic performance testing (e.g., SNR, SINAD, THD) using WaveVision4 software and compatible capture hardware. The board does not operate standalone and requires connection to a WaveVision4 Capture Board (WAVEVSN BRD 4.0) or logic analyzer.

Which ADC device does the ADC122S021EVAL board support?

The ADC122S021EVAL board is configured for the ADC122S021, as confirmed by the top-mark "X18C" on the DUT and schematic designation U3 (MSOP-8). While the board shares mechanical and layout compatibility with other members of the ADCxx2Sxx1 family (e.g., ADC102S021, ADC082S021), its default populated configuration and documented setup procedures are specific to the ADC122S021. Other variants require manual DUT replacement and jumper reconfiguration.

How is the ADC122S021 powered and what voltage range is supported?

The ADC122S021 is powered via the board's adjustable analog supply rail, set using potentiometer VR1 and monitored at test point TP1. The supported range is +2.7V to +5.0V DC, matching the ADC122S021's specified V_A operating range. This voltage also serves as the internal reference, directly scaling the full-scale input range. The board itself receives +5.5V to +5.7V at connector P1, which powers onboard circuitry and supplies +5V to the WaveVision4 Capture Board through isolation diode D1.

Can the ADC122S021EVAL board be used without WaveVision4 software?

Yes - the ADC122S021EVAL board supports standalone operation with external test equipment. Digital output (CS#, SCLK, DIN, DOUT) is accessible at the LA1 logic analyzer header and J2 FutureBus connector, enabling direct capture and analysis using third-party logic analyzers or custom microcontroller interfaces. However, full dynamic performance metrics (SINAD, SFDR, ENOB) and FFT-based analysis require WaveVision4 software and the WAVEVSN BRD 4.0 capture board, as those features rely on synchronized sampling and proprietary post-processing algorithms.

What are the key jumper settings required to evaluate the ADC122S021 on this board?

Essential jumper settings for basic ADC122S021 evaluation include: shorting pins 1–2 of JP1 and JP3 for AC-coupled analog inputs; shorting pins 1–2 of JP2 to route BNC1 to ADC input IN1; shorting pins 1–2 of JP6 to select the on-board oscillator (Y1 or Y2); and installing shorting jumpers on JP1–JP4 as needed for channel selection and coupling mode. All jumpers must be verified per Section 4.8 and Figure 2 of the User's Guide to ensure correct signal routing and avoid grounding or disconnecting active inputs.