Analog Devices Inc. LTC1854IG#PBF

Overview

LTC1854IG#PBF from Analog Devices (formerly Linear Technology) is a 12-bit, 8-channel, 100ksps analog-to-digital converter with ±10V bipolar input range, single-ended or differential programmable MUX, ±30V fault protection on all inputs, and integrated 2.5V reference. It operates from a single 5V supply and targets industrial data acquisition systems requiring high channel density and robust input protection.

For engineers reviewing the LTC1854IG#PBF datasheet, LTC1854IG#PBF pinout, LTC1854IG#PBF application, or LTC1854IG#PBF equivalent, key selection criteria include guaranteed 100ksps sampling rate, ±1LSB INL, SPI/MICROWIRE™-compatible serial interface, Nap/Sleep power shutdown modes (27.5mW / 40µW), and 28-pin SSOP package with exposed ground pad.

Technical Context

The LTC1854IG#PBF employs a successive approximation register (SAR) architecture with internal sample-and-hold and factory-trimmed 5µs max conversion time. Its 8-channel analog multiplexer precedes the ADC core and includes on-chip resistor networks for precise ±10V input scaling and channel-specific overvoltage protection up to ±30V.

It integrates a temperature-compensated 2.5V bandgap reference (±10ppm/°C) and a 4.096V buffered reference output (REFCOMP), supports both internal and external reference configurations, and features dedicated OVDD pin for 3V/5V digital I/O compatibility while maintaining full 12-bit performance across –40°C to +85°C industrial temperature range.

Key Specifications

Pinout & Package

Package: 28-lead plastic SSOP (G package) with exposed pad soldered to PCB ground for thermal and noise performance. Pin count and layout match JEDEC MS-012AC standard.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit, multichannel ADC applications.

Compared with ADS8684IPWR and MAX11620ATI+, the LTC1854IG#PBF uniquely combines fault-protected ±30V inputs, integrated 2.5V/4.096V references, and industrial temperature rating in a single 28-pin SSOP package - reducing system-level component count and validation effort for ruggedized data acquisition.

Availability

LTC1854IG#PBF is available at Aetrix Electronics and suitable for industrial process control, multiplexed data acquisition systems, and high-speed PC-based measurement equipment requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LTC1854IG#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 acquired Linear Technology in 2017 and maintains its high-performance analog product lines, including precision data converters, with global manufacturing and quality certification to ISO 9001 and IATF 16949.

The LTC1854IG#PBF belongs to Linear's legacy high-accuracy, multichannel SAR ADC family designed specifically for industrial and instrumentation applications demanding robust input protection, integrated references, and guaranteed AC/DC specifications across extended temperature ranges.

FAQ

What is the maximum sampling rate guaranteed for the LTC1854IG#PBF?

The LTC1854IG#PBF guarantees a maximum sampling rate of 100ksps across its full operating temperature range (–40°C to +85°C). This is achieved with a typical 4µs acquisition time and 5µs maximum conversion time, and is validated under conditions of VDD = 5V and fSAMPLE = 100kHz. The device also supports up to 166ksps when sampling only the dedicated ADC+ and ADC– pins, bypassing the multiplexer.

Does the LTC1854IG#PBF require an external reference, or does it have an internal one?

The LTC1854IG#PBF includes a factory-trimmed, temperature-compensated 2.5V internal bandgap reference available at the VREF pin (Pin 15), and a buffered 4.096V output at REFCOMP (Pin 16). These eliminate the need for external references in most applications. However, the device supports overdriving VREF with a higher-accuracy external reference if absolute accuracy requirements exceed the internal reference's ±10ppm/°C drift specification.

How does the ±30V fault protection work on the LTC1854IG#PBF inputs?

The LTC1854IG#PBF implements ±30V fault protection on CH0–CH7 and COM pins using internal clamping structures that safely shunt overvoltage currents away from the ADC core. A fault on any unselected channel does not affect the conversion result of the selected channel, and the device remains latch-up free for currents exceeding 100mA below ground or above AVDD. This protection is active regardless of MUX configuration or power state.

Can the LTC1854IG#PBF interface directly with a 3.3V microcontroller?

Yes - the LTC1854IG#PBF supports 3V digital I/O compatibility via its dedicated OVDD pin (Pin 21), which sets the output voltage swing for SDO and BUSY. When OVDD = 3.3V, these outputs drive valid 3.3V logic levels. Its digital inputs (CONVST, RD, SCK, SDI) accept 3V signals directly, as VIH(min) = 2.4V at VDD = 5.25V. No level-shifting circuitry is required for interfacing with 3.3V microcontrollers.

What is the significance of the exposed pad on the LTC1854IG#PBF SSOP package?

The exposed pad on the LTC1854IG#PBF's 28-lead SSOP package (Pin #, electrically connected to GND) must be soldered to a PCB ground plane. This provides critical thermal dissipation (θJA = 160°C/W) and lowers analog ground impedance, directly improving PSRR and reducing noise coupling into the sensitive ADC input path. Failure to solder the pad degrades INL, SINAD, and thermal stability, especially at full 100ksps operation.