Skyworks Solutions Inc. SI83408ADA-IFR

Overview

SI83408ADA-IFR from Skyworks Solutions is a 4-channel isolated smart high-side switch IC with galvanic CMOS isolation, 0.7 A continuous current per channel, 155 mΩ R_ON, 9–32 V switch supply, and Inrush Current Mode (8 A for 20 ms) - designed for driving solenoids, relays, and lamps in industrial PLC I/O modules.

For engineers reviewing the SI83408ADA-IFR datasheet, SI83408ADA-IFR pinout, SI83408ADA-IFR application, or SI83408ADA-IFR equivalent, this page delivers verified specifications, SPI+parallel interface behavior, fault diagnostics mapping, safety-rated isolation performance, and real-world industrial control use cases - all confirmed against Skyworks' official Si834x datasheet Rev. 206512A.

Technical Context

The SI83408ADA-IFR implements four independent high-side switches with integrated voltage/current/temperature sensing, each controlled via parallel logic inputs and monitored via SPI. Its RF-based CMOS isolation barrier provides 1.5 kV_RMS safety rating and >100 kV/µs CMTI, eliminating optocoupler aging and enabling precise timing-critical switching in noisy industrial environments.

It supports dual power domains: 2.25–5.5 V logic supply (VDD1) and 9–32 V isolated switch supply (VDD2), with undervoltage lockout on both rails. Fault reporting includes overcurrent, overtemperature, open-load, and communication error - all accessible via eight status registers and configurable active-low FLT output.

Key Specifications

Pinout & Package

SI83408ADA-IFR uses a compact 9×9 mm DFN-32 package with exposed thermal pad (EP), optimized for high-density industrial PCB layouts and thermal dissipation in sealed enclosures.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-side isolated switch applications.

Compared with SI83408AFA-IFR and SI83414AAA-IFR, SI83408ADA-IFR delivers the same core isolation, protection, and drive capability in the most pin-efficient configuration - ideal for cost-sensitive, space-constrained PLC output cards where SPI diagnostics are sufficient and hardware indicators are unnecessary.

Availability

SI83408ADA-IFR is available at Aetrix Electronics and suitable for industrial programmable logic controllers, motion controller I/O expansion, and smart solid-state relay replacements requiring stable component supply, long lifecycle support, and guaranteed traceability.

Supply support for SI83408ADA-IFR 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

Skyworks Solutions is a global semiconductor company specializing in analog and mixed-signal connectivity solutions for infrastructure, automotive, and industrial markets.

The Si834x product line was engineered specifically for industrial control applications demanding robust galvanic isolation, integrated protection, and diagnostic-rich digital output drivers - replacing legacy optocoupler-plus-MOSFET architectures with single-chip reliability.

FAQ

What is the maximum continuous current per channel for SI83408ADA-IFR?

The SI83408ADA-IFR supports 0.7 A continuous current per channel at 25°C ambient, with derating to 0.5 A at 105°C. This rating is validated across the full 9–32 V switch supply range and accounts for internal thermal limits and R_ON self-heating. The device maintains this current capability without external heatsinking in typical 24 V industrial applications.

Does SI83408ADA-IFR support both high-side and low-side switching configurations?

No - SI83408ADA-IFR is configured exclusively as a high-side switch. Its B1–B4 pins are source terminals designed to connect to load anodes, with cathodes returning to VDD2. Low-side variants (e.g., Si8341x series) exist but are distinct part numbers; SI83408ADA-IFR does not support sink-mode operation.

How does the Inrush Current Mode function in SI83408ADA-IFR?

Inrush Current Mode in SI83408ADA-IFR delivers 8 A peak current for up to 20 ms upon channel activation, automatically disabling once steady-state conditions are detected. This mode is triggered only during initial turn-on and is disabled during normal operation - preventing false overcurrent faults when driving cold incandescent lamps or high-inertia solenoids.

What isolation certifications apply to SI83408ADA-IFR?

SI83408ADA-IFR carries UL 1577 recognition (1500 V_RMS for 1 minute), CSA certification to IEC 62368-1, and CQC approval to GB4943.1. Its 1.5 kV_RMS isolation rating and >100 kV/µs CMTI meet IEC 61131-2 requirements for programmable controllers, making it suitable for safety-critical industrial environments without additional system-level isolation barriers.

Can SI83408ADA-IFR be used without SPI communication?

Yes - SI83408ADA-IFR supports full parallel-only operation using A1–A4 and OE pins for basic ON/OFF control. SPI is optional and used solely for diagnostics, configuration, and fault clearing; all switching functionality remains fully operational without SPI initialization or polling. This enables drop-in replacement of optocoupler-based designs.