Analog Devices Inc. DC547A

Overview

DC547A from Analog Devices (formerly Linear Technology) is an evaluation board for the LTC1864L 16-bit, 150ksps, single-channel, differential-input successive approximation ADC operating from a single 3V supply in an 8-lead MSOP package. It supports true differential analog inputs (IN+, IN–), external reference (VREF), SPI/MICROWIRE-compatible serial interface, and auto-shutdown reducing supply current to 10µA at 1ksps. The board enables high-accuracy data acquisition in portable instrumentation and isolated sensing systems.

For engineers reviewing the DC547A datasheet, DC547A pinout, DC547A application, or DC547A equivalent, this page delivers verified hardware configuration details, supported ADC device identity (LTC1864LAIMS8), on-board signal conditioning (LT1460DCS8-2.5 reference, LT1469 buffer), clock generation (LTC1799 oscillator), and digital interface logic (74AC/74HC family), all validated for ratiometric or externally referenced 16-bit sampling at full 150ksps rate.

Technical Context

The DC547A implements a complete, noise-optimized analog front-end for the LTC1864LAIMS8 ADC, featuring separate analog and digital ground planes, dedicated 3.3V analog (3.3VAN) and digital (3.3VDIG) supplies, and low-ESR bypassing (1µF tantalum on VCC/VREF, 0.1µF ceramics on all ICs). Its layout enforces strict single-point grounding and minimizes analog trace coupling to digital routing - critical for achieving >82dB SNR and ±6 LSB INL over temperature.

Signal flow begins with user-configurable differential input via JP1/JP3 jumpers, conditioned by an LT1469 op-amp buffer, referenced to a precision 2.5V LT1460DCS8-2.5 shunt regulator. Conversion timing is driven by a programmable LTC1799 oscillator and synchronized using 74HC163 counters and 74AC logic, delivering clean CONV, SCK, and SDO waveforms compliant with LTC1864L's tCONV ≤ 4.66µs and tdDO ≤ 55ns specifications.

Key Specifications

Availability

DC547A is available at Aetrix Electronics and suitable for portable instrumentation, battery-powered sensor nodes, and isolated industrial data acquisition requiring stable component supply, full production traceability, and long-term lifecycle support.

Supply support for DC547A 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, acquired Linear Technology in 2017 to strengthen its precision signal chain portfolio.

The DC547A belongs to ADI's Linear Technology Evaluation Board product line, designed specifically to accelerate prototyping and validation of precision ADCs like the LTC1864L/LTC1865L family in real-world signal conditioning and timing-critical applications.

FAQ

What is the primary function of the DC547A evaluation board?

The DC547A evaluation board is a fully assembled and tested hardware platform for evaluating the LTC1864LAIMS8 16-bit, 150ksps, differential-input ADC. It provides all necessary signal conditioning (LT1469 buffer, LT1460 2.5V reference), clock generation (LTC1799), and digital interface logic (74AC/74HC) to demonstrate DC547A's capability to achieve full-resolution performance under real-world PCB layout and noise conditions.

Which specific ADC variant does the DC547A support out-of-the-box?

The DC547A is configured and documented for the LTC1864LAIMS8 - the industrial temperature grade (–40°C to 85°C), 8-lead MSOP-packaged version of the LTC1864L. This variant features true differential analog inputs (IN+, IN–), external VREF pin, and SPI/MICROWIRE-compatible serial I/O, matching the board's JP1/JP3 jumper settings and schematic design.

Does the DC547A support external reference voltages other than 2.5V?

Yes - while the DC547A populates the LT1460DCS8-2.5 as the default 2.5V reference, its VREF net is accessible via test points and header pins (JP4), and the LTC1864LAIMS8 itself supports external reference voltages from 1V to VCC (3.6V max). Users may substitute alternate references (e.g., LT1790, LT6654) by removing C5/C6 and routing the new reference to the VREF node, maintaining <10µV p-p noise per datasheet requirements.

How is clock timing controlled on the DC547A to meet LTC1864L specifications?

Clock timing on the DC547A is generated by the LTC1799 oscillator, whose frequency is set by R10 (10kΩ) to deliver ~150kHz. This signal drives two cascaded 74HC163 counters to produce precise CONV and SCK waveforms with guaranteed setup/hold times (tsuCONV ≥ 60ns, thCONV ≥ 26ns) and duty cycle (45%–55%), fully compliant with LTC1864L's tCONV ≤ 4.66µs and fSCK ≤ 8MHz requirements - verified in the board's AI1 schematic and layout documentation.

Can the DC547A be used to evaluate the LTC1865L 2-channel ADC?

No - the DC547A is specifically designed for the single-channel LTC1864L and lacks the SDI input, CH0/CH1 dual-input routing, and MUX control logic required by the LTC1865L. Its schematic (U3 = LTC1864LAIMS8), pinout mapping (no SDI connection), and firmware-independent hardware architecture are incompatible with LTC1865L's 2-channel multiplexed operation and full-duplex serial interface.