Analog Devices Inc. DC2520A-A

Overview

LTC2344-18 from Analog Devices (formerly Linear Technology) is a quad-channel, 18-bit, 400ksps/ch simultaneous-sampling SAR ADC with differential SoftSpan™ inputs, ±4.096V/0–4.096V/±2.048V/0–2.048V per-channel programmable ranges, integrated 4.096V reference buffer, and dual-mode SPI CMOS/LVDS serial interface. It delivers 95dB SNR, ±4LSB INL (max), and 102dB CMRR for high-precision industrial data acquisition.

For engineers reviewing the LTC2344-18 datasheet, LTC2344-18 pinout, LTC2344-18 application, or LTC2344-18 equivalent, key selection criteria include simultaneous 4-channel sampling at 400ksps, per-channel SoftSpan range reconfiguration, rail-to-rail input overdrive tolerance, guaranteed no missing codes at 18 bits, and operation up to 125°C in the 32-lead 5mm × 5mm QFN package.

Technical Context

The LTC2344-18 employs a successive approximation register (SAR) architecture with internal conversion clock and zero-cycle latency, enabling deterministic timing for real-time control loops. Its analog front-end features fully differential inputs with 0V to VDD common mode range and 102dB CMRR at 200Hz, supporting direct digitization of sensor outputs without external signal conditioning.

Each channel supports independent SoftSpan configuration via SPI command, allowing dynamic range selection on a per-conversion basis - including bipolar (±4.096V, ±2.048V) and unipolar (0–4.096V, 0–2.048V) modes - while maintaining full 18-bit resolution and monotonicity across all ranges.

Key Specifications

Pinout & Package

Package: 32-lead (5mm × 5mm) plastic QFN (UH package) with exposed pad (Pin 33) soldered to PCB ground for thermal and EMI performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-precision multichannel ADC applications.

Compared with AD7606C-18 and ADS8684, the LTC2344-18 uniquely combines per-channel SoftSpan reconfigurability, 102dB CMRR, LVDS/CMOS interface choice, and 125°C operation - making it optimal for thermally demanding, mixed-range, phase-critical industrial and medical systems where signal chain simplicity and timing fidelity are non-negotiable.

Availability

LTC2344-18 is available at Aetrix Electronics and suitable for programmable logic controllers, industrial process control systems, and medical imaging equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LTC2344-18 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 technologies, serving industrial, automotive, communications, and healthcare markets.

The LTC2344-18 belongs to Linear's precision SAR ADC product line, designed specifically for high-channel-count, high-dynamic-range data acquisition in thermally harsh and electrically noisy environments where accuracy, timing coherence, and design simplicity are paramount.

FAQ

What is the maximum sampling rate per channel for the LTC2344-18?

The LTC2344-18 achieves 400ksps per channel when all four channels are simultaneously enabled. Through channel disabling, the rate scales to 500ksps (3 channels), 666ksps (2 channels), or 1Msps (1 channel), with corresponding reduction in total power consumption. This scalability allows optimization for throughput versus channel density in the LTC2344-18 design.

Does the LTC2344-18 require an external reference, or does it include an internal one?

The LTC2344-18 integrates a 2.048V bandgap reference (on REFIN pin) and a buffered 4.096V master reference (on REFBUF pin), eliminating the need for external references in most applications. REFIN can be overdriven with 1.25V–2.2V external references for enhanced accuracy, and REFBUF can be overdriven with 2.5V–5V sources when the internal buffer is disabled - all supported natively by the LTC2344-18.

How does the SoftSpan feature work in the LTC2344-18?

The SoftSpan feature in the LTC2344-18 allows each of the four channels to be independently configured on a per-conversion basis for ±4.096V, 0–4.096V, ±2.048V, or 0–2.048V input ranges - all without changing hardware or sacrificing 18-bit resolution. Configuration is done via SPI command, enabling dynamic adaptation to varying sensor outputs within a single acquisition sequence on the LTC2344-18.

What package type and thermal characteristics does the LTC2344-18 use?

The LTC2344-18 is housed in a 32-lead 5mm × 5mm plastic QFN (UH package) with an exposed thermal pad (Pin 33) that must be soldered to PCB ground. Its θ_JA is 44°C/W, and it is rated for operation from –40°C to 125°C (H-grade), with full specifications guaranteed across this range - a key reliability attribute for the LTC2344-18 in demanding industrial deployments.

Can the LTC2344-18 interface with both FPGA and microcontroller systems?

Yes - the LTC2344-18 supports both SPI CMOS (1.8V–5V logic) and LVDS serial interfaces, selected via the LVDS/CMOS pin. CMOS mode suits standard MCUs and SoCs, while LVDS mode provides noise-immune, high-speed communication with FPGAs and ASICs. The flexible 1–4 lane CMOS data output further enables bandwidth-to-pin-count trade-offs in the LTC2344-18 implementation.