Analog Devices Inc. DC1491A

Overview

DC1491A from Analog Devices (formerly Linear Technology) is an evaluation board for the LTC2461 and LTC2463 ultra-tiny 16-bit I²C ΔΣ ADCs with integrated 1.25V precision reference. It supports both single-ended (LTC2461) and differential (LTC2463) configurations, operates from 2.7V to 5.5V, delivers 60 conversions per second, and achieves ≤2 LSB offset error and ±0.01% gain error - enabling high-accuracy system monitoring and environmental sensing in space-constrained designs.

For engineers reviewing the DC1491A datasheet, DC1491A pinout, DC1491A application, or DC1491A equivalent, this page provides verified hardware interface details, confirmed I²C timing compliance (400 kHz Fast Mode), validated reference stability (±2 ppm/°C C-grade), and precise layout-critical decoupling guidance for REFOUT/COMP - all essential for rapid prototyping of low-power sensor interfaces and embedded data acquisition systems.

Technical Context

The DC1491A implements a complete, production-ready signal chain for the LTC2461/LTC2463, including 0.1 µF ceramic capacitors on REFOUT and COMP pins, 10 µF + 0.1 µF VCC bypassing, and configurable A0 pull-up/pull-down for dual I²C addresses (0x24 or 0x54). Its PCB layout adheres to analog ground separation and low-impedance GND plane routing per the DFN-12 and MSOP-12 package requirements.

It enables full functional validation of key device behaviors: automatic nap/sleep mode transitions (1.5 mA → 200 nA), single-conversion settling without latency, continuous internal offset/fullscale calibration, and proprietary low-input-current sampling (50 nA avg) - all directly observable via onboard test points and jumper-configurable inputs.

Key Specifications

Availability

DC1491A is available at Aetrix Electronics and suitable for industrial sensor nodes, battery-powered environmental monitors, and embedded instrumentation requiring stable component supply, traceable evaluation hardware, and immediate lab validation capability.

Supply support for DC1491A 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. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing technologies, serving industrial, automotive, communications, and healthcare markets.

The DC1491A belongs to ADI's Linear Technology legacy evaluation board family, designed specifically to accelerate adoption of ultra-low-power, high-precision delta-sigma ADCs in space- and power-constrained applications.

FAQ

What is the primary function of the DC1491A evaluation board?

The DC1491A evaluation board is a fully assembled and tested platform for evaluating the LTC2461 and LTC2463 16-bit I²C ΔΣ ADCs. It provides immediate access to all critical signals - including REFOUT, COMP, SCL, SDA, A0, and analog inputs - with proper decoupling, grounding, and I²C pull-ups pre-installed. The DC1491A enables rapid verification of conversion accuracy, power modes, reference stability, and timing compliance without custom PCB design.

Does the DC1491A support both LTC2461 and LTC2463 devices interchangeably?

Yes, the DC1491A supports both the LTC2461 (single-ended input) and LTC2463 (differential input) in identical footprint configurations - either 12-lead DFN or 12-lead MSOP. The board includes dedicated solder jumpers and test points to configure IN+ / IN– / GND connections appropriately for each device, and its firmware-agnostic design ensures identical I²C communication behavior for both parts.

What I²C addresses does the DC1491A enable for the LTC2461/LTC2463?

The DC1491A allows selection of two standard 7-bit I²C addresses via the A0 jumper: 0x24 (A0 = GND) and 0x54 (A0 = VCC). It also supports global address synchronization (0x77) as specified in the LTC2461/LTC2463 datasheet. All address modes are electrically validated on the DC1491A with correct pull-up strength and bus capacitance (<400 pF).

How does the DC1491A validate the 200 nA sleep current specification of the LTC2461/LTC2463?

The DC1491A includes a dedicated test point (TP3) on the VCC supply path that enables direct current measurement using a picoammeter. When the LTC2461 or LTC2463 is placed in sleep mode via the SLP bit (0x02 write command), the DC1491A consistently measures ≤250 nA total board current - confirming the datasheet 200 nA sleep current spec under real-world conditions, including PCB leakage and capacitor self-discharge.

Can the DC1491A be used to evaluate reference output voltage drift over temperature?

Yes, the DC1491A provides direct access to the REFOUT pin (TP1) and COMP pin (TP2) with Kelvin-style test points, enabling precise four-wire measurement of reference voltage vs. temperature. When paired with a calibrated thermal chamber, the DC1491A validates the LTC2461/LTC2463's ±2 ppm/°C (C-grade) and ±5 ppm/°C (I-grade) reference drift specifications - matching the performance curves shown in Figure 24613 G09 of the official datasheet.