Skyworks Solutions Inc. SI8380S-IUR

Overview

SI8380S-IUR from Skyworks Solutions is an 8-channel isolated digital field input IC for industrial PLCs and I/O modules, featuring bipolar (sinking/sourcing) 24 V inputs, integrated 2.5 kVRMS CMOS isolation, serial SPI interface with per-channel configurable debounce filtering, and flow-through output architecture. It enables IEC 61131-2 Type 1/2/3 compliance without field-side VDD.

For engineers reviewing the SI8380S-IUR datasheet, SI8380S-IUR pinout, SI8380S-IUR application, or SI8380S-IUR equivalent, this device supports daisy-chained SPI configuration of up to 16 devices (128 total channels), per-channel filter mode/delay selection (deglitch/low-pass/blanking; 0/10/30/100 ms), and operates from 2.25–5.5 V with –40 to +125 °C temperature range.

Technical Context

The SI8380S-IUR implements a capacitive CMOS isolation barrier with OOK modulation, eliminating optical degradation and enabling high CMTI (300 kV/μs), low propagation delay variation, and stable performance over temperature and lifetime. Its LED emulator front-end requires no field-side power supply while supporting both sourcing and sinking 24 V logic interfaces via internal diode bridge.

It integrates an SPI slave interface with five dedicated registers (CHAN_STATUS, DBNC_MODE0/1, DBNC_DLY0/1) for real-time channel status monitoring and independent debounce configuration per channel - a capability absent in parallel-output Si838x variants. The MOSI_THRU pin enables deterministic daisy-chain timing with CID-based addressing across up to 16 devices.

Key Specifications

Pinout & Package

SI8380S-IUR is housed in a RoHS-compliant 20-pin QSOP package (5.3 mm × 10.2 mm, 0.65 mm pitch) with reinforced creepage/clearance for industrial isolation requirements.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital field input applications.

Compared with SI8380P-IUR, the SI8380S-IUR trades parallel pin count for SPI configurability and daisy-chain scalability; compared with ADUM1401ARWZ, it delivers complete bipolar input signal conditioning in one package - reducing bill-of-materials, layout area, and qualification effort for industrial digital input systems.

Availability

SI8380S-IUR is available at Aetrix Electronics and suitable for programmable logic controllers, industrial data acquisition systems, and distributed control systems requiring stable component supply, long-term lifecycle support, and certified isolation performance.

Supply support for SI8380S-IUR 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, with leadership in RF, timing, and isolation technologies.

The Si838x product line was designed specifically for industrial digital input conditioning - replacing aging optocoupler-based designs with robust, long-life CMOS isolation and intelligent per-channel configuration.

FAQ

What is the isolation rating of the SI8380S-IUR and which safety standards does it meet?

The SI8380S-IUR provides 2.5 kVRMS isolation rating and is certified to UL 1577, VDE 0884-10, CSA Component Notice 5A, IEC 60950-1, IEC 62368-1, and GB4943.1. These approvals validate its use in safety-critical industrial equipment where reinforced insulation between field and logic domains is mandated. The SI8380S-IUR achieves this through Skyworks' proprietary capacitive CMOS isolation technology - not optocouplers - ensuring stable performance over time and temperature.

Does the SI8380S-IUR require a power supply on the field side?

No, the SI8380S-IUR does not require a field-side VDD. Its bipolar LED emulator input draws operating current directly from the 24 V field signal - whether sinking or sourcing - eliminating the need for auxiliary field-side power rails or isolated DC-DC converters. This simplifies system architecture and reduces failure points. The SI8380S-IUR itself only requires a single 2.25–5.5 V logic-side supply (VDD) referenced to GND.

How many SI8380S-IUR devices can be daisy-chained on a single SPI bus?

Up to 16 SI8380S-IUR devices can be daisy-chained using the MOSI_THRU pin and CID-based addressing, supporting a total of 128 isolated digital input channels controlled by one MCU SPI interface. Each device is uniquely addressed via the 4-bit CID field in the SPI control byte, which decrements as the signal propagates down the chain. The SI8380S-IUR's built-in combinational delay on MOSI_THRU limits maximum SCLK frequency based on chain length - full-rate operation is maintained up to 8 devices.

What debounce filter options are available on the SI8380S-IUR and how are they configured?

The SI8380S-IUR supports three debounce filter modes - deglitch, low-pass, and blanking - with four delay options: 0 ms, 10 ms, 30 ms, or 100 ms. These are configured per channel via SPI registers DBNC_MODE0/1 and DBNC_DLY0/1. Unlike parallel-output Si838x variants, the SI8380S-IUR allows independent settings for each of its eight channels. A fixed 4 µs low-pass filter is always active on low-speed paths, but user-selectable delays override this base value. Configuration is performed in-system without hardware changes.

Is the SI8380S-IUR compatible with IEC 61131-2 switch types, and how is compliance achieved?

Yes, the SI8380S-IUR supports IEC 61131-2 Type 1, Type 2, and Type 3 switch compliance through configurable input thresholds and debounce behavior. Compliance is achieved by selecting appropriate external resistor networks (per Section 4.2 of the datasheet) and programming the SI8380S-IUR's per-channel debounce mode and delay via SPI. For example, Type 3 (fast response) uses deglitch mode with 0 ms delay, while Type 1 (slow, noise-immune) uses low-pass mode with 100 ms delay. The SI8380S-IUR's flexibility eliminates the need for multiple part numbers to meet different PLC input specifications.