Analog Devices Inc. LTC2369CMS-18#PBF

Overview

LTC2369CMS-18#PBF from Analog Devices (formerly Linear Technology) is an 18-bit, 1.6 Msps pseudo-differential unipolar successive approximation register (SAR) ADC operating from a single 2.5 V supply. It delivers ±2.5 LSB INL (max), guaranteed no missing codes at 18 bits, and 96.5 dB SNR (typ) at 2 kHz input with 5 V reference - enabling high-fidelity data acquisition in medical imaging and portable instrumentation.

For engineers reviewing the LTC2369CMS-18#PBF datasheet, LTC2369CMS-18#PBF pinout, LTC2369CMS-18#PBF application, or LTC2369CMS-18#PBF equivalent, key selection considerations include its 16-pin MSOP package, SPI-compatible daisy-chain interface, internal conversion clock, 2.5–5.1 V reference support, and guaranteed operation from 0°C to 70°C.

Technical Context

The LTC2369CMS-18#PBF employs a charge-redistribution capacitor DAC (CDAC) architecture with pseudo-differential sampling: IN+ accepts 0 V to VREF, while IN– serves as ground sense with ±100 mV range. Conversion is initiated by a rising edge on CNV, with no pipeline delay and fixed 412 ns conversion time (typ).

Its SPI-compatible serial interface supports 1.8 V to 5 V logic levels via OVDD, includes RDL/SDI dual-function pin for normal/chain mode, and outputs straight-binary 18-bit data MSB-first on SDO synchronized to SCK rising edges - all without external timing components due to integrated oscillator.

Key Specifications

Pinout & Package

Package: 16-lead plastic MSOP (3 mm × 4.9 mm), exposed pad not present (DFN variant has exposed pad; MSOP does not). Pin 1 is CHAIN, pin 16 is GND; pin 17 is absent in MSOP.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS8860IDRCT and AD7606C-18BSTZ, the LTC2369CMS-18#PBF uniquely balances 18-bit resolution, 1.6 Msps speed, ultra-low 18 mW power, and compact MSOP packaging - making it optimal for space-constrained, battery-aware, single-channel precision digitization where daisy-chain scalability matters.

Availability

LTC2369CMS-18#PBF is available at Aetrix Electronics and suitable for medical imaging systems, portable instrumentation, and industrial process control requiring stable component supply with commercial-temperature grade assurance.

Supply support for LTC2369CMS-18#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 semiconductors, formed through the acquisition of Linear Technology in 2017.

The LTC2369-18 belongs to ADI's precision SAR ADC product line, engineered for applications demanding high resolution, low power, and deterministic timing - especially in portable, medical, and industrial data acquisition where SNR, INL, and thermal stability are design-critical.

FAQ

What is the maximum sampling rate supported by the LTC2369CMS-18#PBF?

The LTC2369CMS-18#PBF supports a maximum sampling rate of 1.6 Msps, with guaranteed performance across its full 0°C to 70°C operating temperature range. This rate is enabled by its internal oscillator and optimized CDAC architecture, delivering consistent 412 ns conversion time without external clock dependencies or pipeline latency.

Does the LTC2369CMS-18#PBF require an external reference voltage?

Yes, the LTC2369CMS-18#PBF requires an external reference voltage applied to its dual REF pins (pins 7 and 8). The reference must be between 2.5 V and 5.1 V, low-noise, and well-decoupled with a 47 μF X5R ceramic capacitor. The LTC2369CMS-18#PBF draws up to 1.1 mA DC current from REF at 1.6 Msps, so the reference source must sustain this load without significant droop.

Can the LTC2369CMS-18#PBF interface directly with a 1.8 V microcontroller?

Yes, the LTC2369CMS-18#PBF can interface directly with a 1.8 V microcontroller by setting OVDD = 1.8 V. Its digital I/O pins (SCK, SDO, RDL/SDI, BUSY, CNV, CHAIN) are fully compatible with 1.8 V logic levels, with VIH = 0.8 × OVDD and VIL = 0.2 × OVDD - eliminating the need for external level shifters in mixed-voltage systems.

What is the purpose of the IN– pin on the LTC2369CMS-18#PBF?

The IN– pin on the LTC2369CMS-18#PBF serves as a pseudo-differential ground sense input with a ±100 mV absolute range relative to GND. It is not a true differential input but enables common-mode noise rejection when tied to the local ground plane or remote sensor ground - improving CMRR to 80 dB at 800 kHz and reducing errors from ground shifts in noisy environments.

How does the auto power-down feature work in the LTC2369CMS-18#PBF?

The LTC2369CMS-18#PBF automatically enters power-down mode between conversions when no CNV pulse is asserted. In this state, total supply current drops to 0.9 μA (typ), reducing power dissipation by >99% compared to active 1.6 Msps operation (18 mW). Power-down recovery is instantaneous - the next CNV rising edge fully powers up the ADC and initiates conversion without delay.