Analog Devices Inc. LTC2428IG#PBF

Overview

LTC2428IG#PBF from Analog Devices (formerly Linear Technology) is an 8-channel, 20-bit micropower delta-sigma ADC with no-latency digital filtering, integrated oscillator, 8 ppm INL, and 1.2 ppm RMS noise. It operates from 2.7V to 5.5V, accepts reference voltages from 0.1V to VCC, and delivers valid first-conversion accuracy after channel change-ideal for precision sensor readout in industrial instrumentation and weigh scales.

For engineers reviewing the LTC2428IG#PBF datasheet, LTC2428IG#PBF pinout, LTC2428IG#PBF application, or LTC2428IG#PBF equivalent, key selection criteria include its single-cycle filter settling, 110 dB 50/60 Hz notch rejection, extended input range (–12.5% to +112.5% VREF), SPI/MICROWIRE-compatible 4-wire interface, and –40°C to +85°C industrial temperature grade.

Technical Context

The LTC2428IG#PBF implements a decimating FIR filter synchronized to an internal oscillator or user-supplied external clock (1 Hz–800 Hz), enabling programmable line-frequency rejection. Its auto-calibrating architecture performs offset and full-scale correction every conversion cycle without interrupting operation.

It integrates an 8-channel analog multiplexer with 250 Ω on-resistance (VCC = 2.7V), supports live-zero input ranging via separate FSSET and ZSSET pins, and uses a 24-bit serial output format where the first 4 bits indicate sign/range/status and the remaining 20 bits convey the conversion result.

Key Specifications

Pinout & Package

Package: 28-lead plastic SSOP (G package), 5.6 mm × 10.2 mm, 0.635 mm pitch, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC2424IG#PBF and AD7798BRUZ, the LTC2428IG#PBF uniquely combines 20-bit resolution, true 8-channel operation, no-latency settling, and self-contained oscillator-all in an industrial-grade SSOP package-making it optimal for new high-precision, low-power multiplexed sensor systems.

Availability

LTC2428IG#PBF is available at Aetrix Electronics and suitable for weight scales, direct temperature measurement, gas analyzers, strain-gage transducers, and industrial process control requiring stable component supply and long-term manufacturability.

Supply support for LTC2428IG#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 LTC2428IG#PBF belongs to ADI's precision delta-sigma ADC product line, engineered for high-resolution, low-power, multiplexed sensor interfacing in harsh industrial environments where accuracy, noise immunity, and long-term stability are critical.

FAQ

What is the operating temperature range of the LTC2428IG#PBF?

The LTC2428IG#PBF is specified for operation from –40°C to +85°C, meeting industrial-grade reliability requirements. This range is confirmed by the "I" grade suffix in the part number and validated across all key specifications including INL, noise, and power supply rejection in the datasheet's "Operating Temperature Range" table.

Does the LTC2428IG#PBF require external components for its oscillator function?

No, the LTC2428IG#PBF includes a fully integrated, factory-trimmed oscillator that requires no external capacitors, crystals, or resistors. When the FO pin is tied to GND or VCC, the device automatically configures for 60 Hz or 50 Hz notch rejection respectively-enabling immediate use without timing component selection.

How does the LTC2428IG#PBF achieve "no latency" in multiplexed operation?

The LTC2428IG#PBF achieves no-latency operation through a single-cycle decimating FIR filter synchronized to its internal or external clock. Unlike conventional sigma-delta converters, it guarantees the first conversion after a channel change is valid and fully settled-eliminating the need for dummy conversions or software discard cycles.

Can the LTC2428IG#PBF interface directly with a standard SPI controller?

Yes, the LTC2428IG#PBF supports SPI-compatible timing with CSADC as chip select, SDO as MOSI-equivalent output, and SCK as serial clock. Its 4-wire interface (CSADC, SCK, SDO, DIN) aligns with SPI Mode 0 (CPOL = 0, CPHA = 0), and data is sampled on the rising edge of SCK-requiring no protocol translation or bit-banging.

What is the purpose of the ZSSET and FSSET pins on the LTC2428IG#PBF?

The ZSSET and FSSET pins define the zero-scale and full-scale reference points for the LTC2428IG#PBF's extended input range. Their difference (VREF = FSSET – ZSSET) sets the reference voltage, enabling live-zero operation from –12.5% to +112.5% VREF-critical for handling sensor offsets and overrange conditions without external level-shifting circuitry.