Analog Devices Inc. LTC2378CMS-20#PBF

Overview

LTC2378CMS-20#PBF from Analog Devices (formerly Linear Technology) is a 20-bit, 1 Msps successive approximation register (SAR) analog-to-digital converter with ±0.5 ppm typical integral nonlinearity, 104 dB SNR at 2 kHz, and 21 mW power consumption at full throughput. It operates from a 2.5 V supply, supports ±V_REF fully differential input range (V_REF = 2.5 V to 5.1 V), and integrates digital gain compression (DGC) for single-supply amplifier interfacing - used in high-precision medical imaging and portable instrumentation.

For engineers reviewing the LTC2378CMS-20#PBF datasheet, LTC2378CMS-20#PBF pinout, LTC2378CMS-20#PBF application, or LTC2378CMS-20#PBF equivalent, key selection criteria include guaranteed 20-bit no-missing-codes performance, daisy-chain SPI interface compatibility, internal conversion clock, and DGC-enabled 0.5 V to 4.5 V input range with 5 V reference.

Technical Context

The LTC2378CMS-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 conversion timing is governed by an internal oscillator, eliminating external clock dependency for sampling.

Digital gain compression (DGC) is implemented via on-chip digital scaling that remaps zero-scale from 0 V to 0.1·V_REF and full-scale from V_REF to 0.9·V_REF, enabling rail-to-rail input swing accommodation using only a single positive supply for the driving amplifier.

Key Specifications

Pinout & Package

The LTC2378CMS-20#PBF is housed in a 16-lead plastic MSOP package (4.0 mm × 3.0 mm × 1.1 mm), with exposed pad not present (DFN variant has exposed pad; MSOP does not). Pin 17 is absent in MSOP; all ground pins (3, 6, 10, 16) must be connected to PCB ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS127L01IRHBT and AD7626BCPZ, the LTC2378CMS-20#PBF uniquely balances 20-bit no-missing-codes accuracy, 1 Msps speed, integrated DGC, and internal clock - making it optimal for portable, thermally constrained, single-supply high-speed precision digitization where resolution, speed, and interface simplicity are jointly critical.

Availability

LTC2378CMS-20#PBF is available at Aetrix Electronics and suitable for medical imaging systems, portable instrumentation, and industrial process control applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for LTC2378CMS-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 LTC2378-20 belongs to ADI's precision SAR ADC product line, engineered for applications demanding metrology-grade linearity, low power, and simplified system integration - especially where single-supply front-end design and deterministic latency are essential.

FAQ

What is the maximum operating temperature range for the LTC2378CMS-20#PBF?

The LTC2378CMS-20#PBF is specified for operation from 0°C to 70°C (Commercial grade). This temperature range is confirmed in the Absolute Maximum Ratings and Order Information tables, where "C" grade denotes 0°C to 70°C. The MSOP package variant LTC2378IMS-20#PBF supports –40°C to 85°C, but the LTC2378CMS-20#PBF itself is rated only to 70°C ambient.

Does the LTC2378CMS-20#PBF require an external reference voltage?

Yes, the LTC2378CMS-20#PBF requires an external reference voltage applied to the REF pin. The device supports V_REF from 2.5 V to 5.1 V, and the reference must be externally sourced and decoupled with a 47 µF X7R ceramic capacitor. No internal reference is provided; the REF/DGC pin controls digital gain compression but does not generate reference voltage.

How does digital gain compression (DGC) affect the input voltage range of the LTC2378CMS-20#PBF?

When DGC is enabled (REF/DGC pin tied to GND), the LTC2378CMS-20#PBF maps zero-scale from 0 V to 0.1·V_REF and full-scale from V_REF to 0.9·V_REF. With a 5 V reference, this yields an effective input range of 0.5 V to 4.5 V - providing 0.5 V headroom at both rails to accommodate amplifier output swing from a single 5.5 V supply, while preserving full 20-bit resolution.

Can the LTC2378CMS-20#PBF interface directly with a 1.8 V microcontroller?

Yes, the LTC2378CMS-20#PBF supports 1.8 V logic levels via its OVDD pin, which accepts 1.71 V to 5.25 V. When OVDD = 1.8 V, all digital inputs (CNV, SCK, CHAIN, RDL/SDI) recognize 0.2·OVDD (0.36 V) as logic low and 0.8·OVDD (1.44 V) as logic high, and SDO outputs are compatible with 1.8 V receivers - enabling direct connection without level shifters.

Is the LTC2378CMS-20#PBF pin-compatible with other members of the LTC2378 family?

Yes, the LTC2378CMS-20#PBF shares identical pinout and footprint with all 16-lead MSOP variants in the LTC2378 family (e.g., LTC2378IMS-20#PBF, LTC2378CMS-18#PBF), including same pin functions, spacing, and thermal pad absence. However, temperature grade (C vs I) and resolution (20-bit vs 18-bit) differ - electrical compatibility requires verifying VDD, REF, and timing specifications per datasheet section.