Analog Devices Inc. LTC1865LACS8#TRPBF

Overview

LTC1865LACS8#TRPBF from Analog Devices (formerly Linear Technology) is a 16-bit, 150ksps, 2-channel software-selectable multiplexed successive approximation ADC in an 8-lead SO-8 package, operating from a single 3V supply with 450µA typical supply current at full speed and auto shutdown to 10µA at 1ksps. It features true differential or single-ended input modes, SPI/MICROWIRE-compatible 3-wire serial interface, external reference support (VREF = 1V to VCC), and rail-to-rail analog input capability when IN– is grounded.

For engineers reviewing the LTC1865LACS8#TRPBF datasheet, LTC1865LACS8#TRPBF pinout, LTC1865LACS8#TRPBF application, or LTC1865LACS8#TRPBF equivalent, key selection criteria include its 16-bit resolution at 150ksps, low-power operation down to 10µA sleep current, software-configurable dual-channel MUX, and compatibility with ratiometric or precision external reference designs in compact battery-powered systems.

Technical Context

The LTC1865LACS8#TRPBF implements a switched-capacitor SAR architecture with integrated sample-and-hold, supporting both differential and single-ended acquisition via a 2-bit configuration word shifted into SDI. Its conversion timing is fixed at 3.7–4.66µs, synchronized by CONV rising edge, with data output on SDO synchronized to SCK falling edge.

It uses separate analog and digital ground connections in MSOP variants, but the SO-8 variant (including LTC1865LACS8#TRPBF) consolidates to a single GND pin and internally ties VREF to VCC - resulting in a fixed full-scale span of VCC (2.7V to 3.6V), unlike the MSOP version which supports externally adjustable VREF from 1V to VCC.

Key Specifications

Pinout & Package

Package: 8-lead plastic SO-8 (narrow, 0.150-inch width), JEDEC MS-012AC, 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 LTC1865LIMS8#TRPBF, the LTC1865LACS8#TRPBF trades reference configurability and ground separation for lower cost, smaller footprint, and simplified layout in SO-8 - while compared with ADS8325IDR, it delivers 50% higher throughput and 60% lower active current, at the expense of supply voltage headroom and on-chip reference features.

Availability

LTC1865LACS8#TRPBF is available at Aetrix Electronics and suitable for portable medical sensors, industrial process monitoring, and isolated data acquisition modules requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for LTC1865LACS8#TRPBF 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, serving industrial, automotive, communications, and healthcare markets.

The LTC1865L series belongs to ADI's legacy Linear Technology precision data acquisition portfolio, designed specifically for ultra-low-power, high-resolution digitization in space- and energy-constrained embedded systems.

FAQ

What is the maximum sampling rate supported by the LTC1865LACS8#TRPBF?

The LTC1865LACS8#TRPBF supports a maximum sampling rate of 150 ksps, with a guaranteed conversion time of 3.7–4.66 µs. This rate is achievable with SCK up to 8 MHz and proper timing margins per the datasheet's recommended operating conditions. At this rate, the device draws 450 µA typical supply current from a 3V supply.

Does the LTC1865LACS8#TRPBF require an external reference voltage?

No - the LTC1865LACS8#TRPBF is the SO-8 variant in which VREF is internally tied to VCC, making it self-referenced with a full-scale range equal to the supply voltage (2.7V to 3.6V). This eliminates the need for an external reference component, reducing BOM cost and board area compared to the MSOP version (e.g., LTC1865LIMS8#TRPBF), which supports external VREF.

How does the software-selectable MUX work on the LTC1865LACS8#TRPBF?

The LTC1865LACS8#TRPBF uses a 2-bit configuration word shifted into the SDI pin after CONV falls low. The word selects one of four input configurations: CH0–GND, CH1–GND, CH0–CH1, or CH1–CH0. This allows dynamic channel selection without external hardware, enabling flexible multi-sensor acquisition within a single conversion cycle.

What is the supply current of the LTC1865LACS8#TRPBF in shutdown mode?

In shutdown mode - achieved by holding CONV high after conversion completes - the LTC1865LACS8#TRPBF draws only 10 µA typical supply current at 1 ksps sampling rate. This auto power-down feature significantly reduces average power in duty-cycled applications, such as battery-operated environmental sensors that wake periodically to acquire data.

Is the LTC1865LACS8#TRPBF pin-compatible with earlier 12-bit versions like the LTC1860LCS8#TRPBF?

Yes - the LTC1865LACS8#TRPBF is pin-compatible with the 12-bit LTC1860L/LTC1861L family in the SO-8 package, sharing identical pin functions and layout. This allows direct 16-bit resolution upgrades in existing designs without PCB revision, provided the host firmware accommodates the extended 16-bit data word and updated timing requirements.