Analog Devices Inc. DC790A

Overview

DC790A from Analog Devices (formerly Linear Technology) is a fully assembled, factory-tested demonstration board for the LTC2439-1 16-channel, 16-bit no-latency delta-sigma ADC. It provides direct sensor digitization with 1 µV RMS noise, 0.12 LSB INL, and simultaneous 50/60 Hz notch rejection - enabling high-accuracy weigh scales, strain gauge interfaces, and industrial process monitoring without external calibration or filtering components.

For engineers reviewing the DC790A datasheet, DC790A pinout, DC790A application, or DC790A equivalent, this page delivers verified hardware configuration details, supported interface modes (SPI/MICROWIRE), reference voltage flexibility (0.1 V to VCC), differential/single-ended channel mapping, and real-world performance validation data - all specific to the DC790A evaluation platform.

Technical Context

The DC790A implements the LTC2439-1 in a fixed 28-lead SSOP footprint with on-board 10 µF + 0.1 µF VCC bypassing, selectable reference sources (internal 2.5 V or external), and configurable FO pin routing for internal oscillator (50/60 Hz rejection) or external clock input. All 16 analog inputs (CH0–CH15) and COM are brought out to screw terminals and test points.

It supports both internal SCK (SCK as output, 17.5 kHz typical) and external SCK (SCK as input, up to 2 MHz) serial interface timing modes, and enables full 19-bit output readout including EOC, sign, and over/underrange status bits - matching the LTC2439-1's native protocol without translation or firmware abstraction.

Key Specifications

Availability

DC790A is available at Aetrix Electronics and suitable for industrial process control, precision weigh scale development, and sensor-to-digital interface prototyping requiring stable component supply, traceable evaluation hardware, and documented signal chain validation.

Supply support for DC790A 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

Analog Devices, Inc. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors - serving precision measurement, industrial automation, and instrumentation markets.

The DC790A belongs to Analog Devices' Linear Technology Evaluation Board product line, designed to accelerate time-to-prototype for high-resolution data acquisition systems using their precision delta-sigma ADCs.

FAQ

What is the primary function of the DC790A evaluation board?

The DC790A evaluation board is a ready-to-use hardware platform for evaluating the LTC2439-1 16-channel 16-bit delta-sigma ADC. It provides complete signal conditioning, power regulation, reference selection, and SPI/MICROWIRE interface circuitry - allowing engineers to validate sensor interface performance, verify timing behavior, and develop firmware directly with the DC790A without custom PCB design.

Does the DC790A support both differential and single-ended input configurations for the LTC2439-1?

Yes, the DC790A fully supports both modes. It routes all 16 analog inputs (CH0–CH15) and the COM pin to accessible terminals, enabling user-defined differential pair selection (e.g., CH0–CH1) or single-ended measurements (e.g., CH0 vs COM). The board's jumper options and documentation align with the LTC2439-1's SGL/ODD control bit mapping defined in Table 1 of the DC790A's supporting LTC2439-1 datasheet.

Can the DC790A operate with an external reference voltage lower than 2.5 V?

Yes - the DC790A supports external differential reference voltages from 0.1 V to VCC, consistent with the LTC2439-1 specification. Its onboard reference header accepts externally supplied references (e.g., precision 1.25 V or 100 mV sources), and layout maintains low-noise grounding to preserve the LTC2439-1's 1 µV RMS noise floor even at minimum VREF.

How does the DC790A implement 50 Hz and 60 Hz line rejection?

The DC790A configures the LTC2439-1's FO pin to GND by default, activating its internal oscillator and delivering simultaneous 87 dB minimum rejection at 50 Hz and 60 Hz ±2%. No external clock or filter components are needed. An alternative FO header allows connection to an external oscillator (2.56–2000 kHz) for custom notch frequencies if required.

Is the DC790A compatible with standard SPI host controllers?

Yes - the DC790A implements the LTC2439-1's native 4-wire SPI/MICROWIRE interface with CS, SDO, SDI, and SCK routed to a standard 0.1"-spaced header. It operates in both internal SCK mode (SCK output, ~17.5 kHz) and external SCK mode (SCK input, up to 2 MHz), and outputs full 19-bit frames including EOC, sign, and over/underrange flags - all directly readable by off-the-shelf microcontrollers and logic analyzers.