Analog Devices Inc. LTC4310CMS-2#PBF

Overview

LTC4310CMS-2#PBF from Analog Devices (formerly Linear Technology) is a bidirectional I²C isolator IC designed for hot-swappable, galvanically isolated communication between two I²C buses with separate ground domains. It supports 400kHz I²C operation, provides ±5kV HBM ESD protection, features rise time accelerators delivering up to 6mA pull-up current, and integrates stuck-bus recovery with automatic 16-clock generation and STOP-bit issuance. It is used in isolated power supply monitoring and PoE-powered device management.

For engineers reviewing the LTC4310CMS-2#PBF datasheet, LTC4310CMS-2#PBF pinout, LTC4310CMS-2#PBF application, or LTC4310CMS-2#PBF equivalent, key selection criteria include its 400kHz maximum SCL frequency, 10-lead MSOP package with exposed pad, dual-mode isolation barrier interface (transformer or capacitor-coupled), thermal shutdown at 150°C, and EN-controlled low-power shutdown mode drawing only 0.1µA.

Technical Context

The LTC4310CMS-2#PBF implements event-driven differential pulse transmission across an isolation barrier using TXP/TXN outputs and RXP/RXN inputs, with noise immunity rejecting signals below 500mV differential amplitude. Its logic detection circuitry distinguishes local bus activity from self-driven outputs, enabling seamless clock stretching, arbitration, and ACK/NACK handling across isolation.

It employs dual-stage bus rise control: first limiting dV/dt to ≤6.9 V/µs (at VCC = 5.5V) via active slew regulation between 0V and 0.35•VCC, then activating 2–6mA rise time acceleration above 0.45•VCC. Stuck-bus recovery triggers after 37ms of SDA/SCL low state, initiating clock pulses and STOP-bit generation without external intervention.

Key Specifications

Pinout & Package

Package: 10-lead MSOP (3mm × 3mm footprint, 0.5mm pitch), with exposed thermal pad (optional GND connection). Pin count and physical layout match industry-standard MSOP-10 footprint.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I²C isolation applications.

Compared with ADM3260ARUZ and ISO1540DR, the LTC4310CMS-2#PBF uniquely combines 400kHz I²C support, integrated rise time acceleration, and autonomous stuck-bus recovery in a compact MSOP package-making it optimal for robust, high-speed isolated telemetry in industrial and medical systems where bus reliability is critical.

Availability

LTC4310CMS-2#PBF is available at Aetrix Electronics and suitable for industrial sensor hubs, power supply telemetry, Power-over-Ethernet endpoints, and medical diagnostic equipment requiring stable component supply and long-term production continuity.

Supply support for LTC4310CMS-2#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. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors for precision instrumentation, industrial automation, and communications infrastructure.

The LTC4310 product line was designed specifically for robust, protocol-transparent I²C isolation in harsh environments-targeting applications demanding hot-swap capability, high ESD immunity, and autonomous bus fault recovery without host processor involvement.

FAQ

What is the maximum I²C clock frequency supported by the LTC4310CMS-2#PBF?

The LTC4310CMS-2#PBF supports a maximum SCL clock frequency of 400kHz, compliant with I²C Fast Mode Plus specifications. This is explicitly defined for the "-2" variant in the datasheet and validated across the full 0°C to 70°C operating temperature range. The LTC4310CMS-2#PBF achieves this using enhanced rise time acceleration and tighter dV/dt control compared to the -1 version.

Does the LTC4310CMS-2#PBF require external components for basic I²C isolation operation?

Yes, the LTC4310CMS-2#PBF requires external components: pull-up resistors on SDA and SCL (value dependent on bus capacitance and voltage), a 0.01µF bypass capacitor on VCC-to-GND, and either an Ethernet transformer (e.g., EPF8119S) or coupling capacitors connecting TXP/TXN to RXP/RXN across the isolation barrier. No external logic or microcontroller is needed for core isolation functionality.

How does the LTC4310CMS-2#PBF handle a stuck I²C bus condition?

The LTC4310CMS-2#PBF detects a stuck bus when SDA and SCL remain low for 37ms, then autonomously generates up to sixteen SCL clock pulses followed by a STOP bit to attempt recovery-without host intervention. If successful, it resumes normal operation after detecting simultaneous bus idle or STOP on both sides. This behavior is hard-coded in silicon and applies identically to the LTC4310CMS-2#PBF.

Can the LTC4310CMS-2#PBF operate with different supply voltages on each side of the isolation barrier?

Yes, the LTC4310CMS-2#PBF supports independent VCC supplies on each side-e.g., 3.3V on one side and 5V on the other-because its SDA and SCL I/Os are level-shifted and electrically isolated. The device itself only requires one VCC supply per IC; the isolation barrier (transformer or capacitors) inherently decouples ground and voltage domains between the two I²C buses linked by the LTC4310CMS-2#PBF.

What is the role of the READY pin on the LTC4310CMS-2#PBF?

The READY pin on the LTC4310CMS-2#PBF is an open-drain output that pulls low when the device has completed startup, synchronized both I²C buses, and is actively driving SDA/SCL based on received RXP/RXN signals. It serves as a hardware handshake indicating the isolation link is fully established and ready for Hot Swap™ card insertion-critical for system-level fault containment in modular architectures.