Analog Devices Inc. LTC1865LACS8#PBF

Overview

LTC1865LACS8#PBF from Analog Devices (formerly Linear Technology) is a 16-bit, 150ksps successive approximation ADC with software-selectable 2-channel MUX in an 8-lead SO-8 package, operating on a single 3V supply. It features true differential or single-ended input modes, external reference support (VREF = 1V to VCC), SPI/MICROWIRE-compatible serial interface, and auto-shutdown reducing supply current to 10µA at 1ksps - ideal for low-power portable instrumentation and isolated data acquisition.

For engineers reviewing the LTC1865LACS8#PBF datasheet, LTC1865LACS8#PBF pinout, LTC1865LACS8#PBF application, or LTC1865LACS8#PBF equivalent, key selection criteria include its 16-bit resolution at 150ksps, SO-8 footprint compatibility with 12-bit LTC1860L/LTC1861L, rail-to-rail analog input capability when VREF = VCC, and differential noise rejection in high-EMI environments.

Technical Context

The LTC1865LACS8#PBF implements a switched-capacitor SAR architecture with integrated sample-and-hold, supporting both unipolar differential and single-ended input configurations via a 2-bit SDI control word. Its internal multiplexer allows dynamic channel selection between CH0 and CH1 relative to GND or each other, enabling flexible signal routing without external switching components.

It uses a 3-wire serial interface (CONV, SCK, SDO/SDI) with full-duplex operation: configuration bits are clocked in on SDI during CONV low, and conversion results are shifted out on SDO synchronized to SCK falling edges. The SO-8 variant ties VREF internally to VCC, fixing full-scale span to VCC, unlike the MSOP version which accepts external VREF.

Key Specifications

Pinout & Package

Package: 8-lead plastic SO (narrow, 0.150-inch width), JEDEC MS-012AC compliant, body size 4.90 mm × 3.90 mm, lead pitch 1.27 mm.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit SAR ADC applications.

Compared with LTC1865LIS8#PBF, the LTC1865LACS8#PBF trades extended temperature range for lower cost in commercial applications; versus ADS8325IDR, it offers superior power efficiency and seamless drop-in replacement for legacy LTC1860L designs - critical for minimizing validation effort and production risk.

Availability

LTC1865LACS8#PBF is available at Aetrix Electronics and suitable for portable instrumentation, isolated data acquisition, and low-power battery monitoring requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production lots.

Supply support for LTC1865LACS8#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 LTC1865L series belongs to ADI's precision data acquisition product line, designed specifically for compact, low-power, high-resolution measurement systems where board space, energy efficiency, and signal fidelity are critical constraints.

FAQ

What is the maximum sampling rate of the LTC1865LACS8#PBF?

The LTC1865LACS8#PBF achieves a maximum sampling rate of 150 ksps under recommended operating conditions (VCC = 2.7V–3.6V, fSCK ≤ 8 MHz). At this rate, the conversion time is 4.66 µs, and the device draws 450 µA typical supply current. Performance remains specified across the full 0°C to 70°C commercial temperature range.

Does the LTC1865LACS8#PBF require an external voltage reference?

No - the LTC1865LACS8#PBF is the SO-8 package variant in which the VREF pin is tied internally to VCC. This means the full-scale range is fixed to VCC (e.g., 3V), eliminating the need for an external reference. In contrast, the MSOP versions (e.g., LTC1865LMS8#PBF) support external VREF from 1V to VCC.

How does the 2-channel multiplexer work in the LTC1865LACS8#PBF?

The LTC1865LACS8#PBF uses a 2-bit configuration word shifted into SDI during the CONV low period to select between four input combinations: CH0–GND, CH1–GND, CH0–CH1, or CH1–CH0. This enables software-controlled differential or single-ended measurements without external switches - all within one SO-8 package.

What is the power consumption of the LTC1865LACS8#PBF at 1 ksps?

At 1 ksps, the LTC1865LACS8#PBF enters auto-shutdown mode between conversions, drawing only 10 µA typical supply current. This ultra-low quiescent current significantly extends battery life in duty-cycled applications such as wireless sensor nodes or handheld test equipment.

Is the LTC1865LACS8#PBF pin-compatible with older 12-bit ADCs?

Yes - the LTC1865LACS8#PBF is pin-compatible with the 12-bit LTC1860L and LTC1861L in the same SO-8 package. This allows direct 16-bit resolution upgrade without PCB layout changes, preserving existing schematics, footprints, and firmware interface logic while improving measurement accuracy and dynamic range.