Analog Devices Inc. LTC2377IDE-20#PBF

Overview

LTC2377IDE-20#PBF from Analog Devices (formerly Linear Technology) is a 20-bit, 500ksps successive approximation register (SAR) analog-to-digital converter with ±0.5ppm typical integral nonlinearity, 104dB SNR at 2kHz, and digital gain compression (DGC) for single-supply amplifier interfacing. It operates from a 2.5V analog supply and supports ±V_REF fully differential input ranges with V_REF from 2.5V to 5.1V, targeting high-precision data acquisition in medical imaging and portable instrumentation.

For engineers reviewing the LTC2377IDE-20#PBF datasheet, LTC2377IDE-20#PBF pinout, LTC2377IDE-20#PBF application, or LTC2377IDE-20#PBF equivalent, key selection criteria include guaranteed 20-bit no-missing-codes performance, daisy-chain SPI interface compatibility across 1.8V–5V logic levels, internal conversion clock, and DGC-enabled 0.5V–4.5V input range with 5V reference.

Technical Context

The LTC2377IDE-20#PBF implements a charge-redistribution SAR architecture with a 20-bit CDAC and differential comparator, achieving no pipeline delay and zero cycle latency. Its internal oscillator eliminates external timing dependencies, while auto power-down between conversions scales dissipation from 10.5mW at 500ksps to 10.5µW at 500sps.

Digital gain compression (DGC) remaps the transfer function so zero-scale shifts from 0V to 0.1·V_REF and full-scale from V_REF to 0.9·V_REF, enabling rail-to-rail input swing without negative supply for driving amplifiers. The device supports daisy-chain mode via CHAIN pin control and SPI-compatible serial I/O with MSB-first 2's complement output.

Key Specifications

Pinout & Package

Package: 16-lead (4mm × 3mm) plastic DFN with exposed pad (Pin 17 = GND). Rated for –40°C to +85°C operation (I-grade).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-resolution SAR ADC applications.

Compared with ADS127L11IRHBT and AD4022BCPZ-RL7, the LTC2377IDE-20#PBF uniquely balances 500ksps speed, 104dB SNR, ±0.5ppm INL, and DGC-enabled single-supply operation - making it optimal for portable, high-fidelity data acquisition where power, size, and analog interface simplicity are jointly constrained.

Availability

LTC2377IDE-20#PBF is available at Aetrix Electronics and suitable for medical imaging systems, portable instrumentation, and industrial process control requiring stable component supply with guaranteed long-term availability and full temperature-grade compliance.

Supply support for LTC2377IDE-20#PBF 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 LTC2377IDE-20#PBF belongs to ADI's precision SAR ADC product line, engineered for applications demanding metrology-grade accuracy, low power, and simplified analog interface design - especially where single-supply operation and deterministic timing are critical.

FAQ

What is the operating temperature range for the LTC2377IDE-20#PBF?

The LTC2377IDE-20#PBF is rated for –40°C to +85°C operation (I-grade), verified across all electrical specifications including INL, SNR, and timing parameters. This makes it suitable for industrial and automotive-adjacent applications where ambient temperatures exceed commercial grade limits. The DFN package's exposed pad enhances thermal performance under sustained 500ksps operation.

Does the LTC2377IDE-20#PBF require an external clock for conversion timing?

No, the LTC2377IDE-20#PBF features an internal oscillator that sets conversion time, eliminating the need for an external clock source. This simplifies system design and improves timing predictability. External clocks are only used for the SPI interface (SCK), which operates independently and supports frequencies up to 100MHz - the LTC2377IDE-20#PBF itself handles all internal sampling and conversion timing autonomously.

How does Digital Gain Compression (DGC) work in the LTC2377IDE-20#PBF?

Digital Gain Compression (DGC) in the LTC2377IDE-20#PBF is activated by grounding the REF/DGC pin. It digitally remaps the transfer function so zero-scale corresponds to 0.1·V_REF and full-scale to 0.9·V_REF, effectively compressing the usable input range to 0.5V–4.5V with a 5V reference. This preserves full 20-bit resolution while allowing the driving amplifier to operate from a single 5.5V supply - eliminating the need for a negative rail.

What are the key layout recommendations for the LTC2377IDE-20#PBF's REF and analog input pins?

For optimal performance, the REF pin must be decoupled with a 47µF X7R ceramic capacitor (1210 size, 10V rating) placed as close as possible to the pin. Analog inputs (IN+, IN–) require matched 10Ω–50Ω series source impedances and symmetric routing. The exposed pad (Pin 17) must be soldered to a solid ground plane. Avoid sharing analog and digital ground traces; use separate AGND and DGND planes joined at a single point near the VDD/GND bypass capacitors.

Can the LTC2377IDE-20#PBF be used in daisy-chain configuration with other ADCs?

Yes, the LTC2377IDE-20#PBF supports daisy-chain mode via the CHAIN pin. When CHAIN is high, RDL/SDI functions as serial data input, allowing multiple LTC2377IDE-20#PBF devices to share a single SPI bus. Each device shifts its 20-bit result into the next, enabling synchronized multi-channel acquisition with minimal GPIO usage. The SCK period in chain mode is specified at 13.5ns minimum to accommodate propagation delays.