Skyworks Solutions Inc. SI86SQ44BE-IS2R

Overview

SI86SQ44BE-IS2R from Skyworks Solutions is a 5-channel reinforced digital isolator optimized for Quad SPI (QSPI) bus isolation in high-reliability automotive and industrial systems. It features four bidirectional channels with programmable direction control via DIR/ISO_DIR pins, one dedicated forward-direction channel, 150 Mbps data rate, 10 ns typical propagation delay, and 6000 VRMS reinforced isolation per UL 1577. It operates across –40 to +125 °C and supports dual 2.25–5.5 V supplies.

For engineers reviewing the SI86SQ44BE-IS2R datasheet, SI86SQ44BE-IS2R pinout, SI86SQ44BE-IS2R application, or SI86SQ44BE-IS2R equivalent, this device is selected for isolated QSPI memory interfaces requiring configurable signal flow, fail-safe output states during power loss, and AEC-Q100 qualification for onboard chargers and battery management systems.

Technical Context

The SI86SQ44BE-IS2R implements RF-based on/off keying across a semiconductor isolation barrier, eliminating startup initialization and enabling robust noise immunity (100 kV/µs CMTI). Its custom QSPI mode uses a single DIR input to configure all four bidirectional channels simultaneously, with ISO_DIR providing an isolated copy of that state for side-B logic synchronization.

Each side includes independent undervoltage lockout (UVLO) and reset circuitry (RSTB threshold ~1.7 V), ensuring deterministic behavior during supply ramp-up/down. The device supports tri-state outputs via EN_A/EN_B pins and offers selectable fail-safe default output (high or low) when one supply is unpowered - configured at order time and confirmed by the "-BE" suffix.

Key Specifications

Pinout & Package

SI86SQ44BE-IS2R is housed in a WB SOIC-16 (wide-body small-outline integrated circuit) package with 8.3 mm creepage/clearance, supporting 6000 VRMS isolation. Pin 1 is marked with a dot; pin 16 is VDD2.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADUM3481CRWZ and ISO6741QDWR, SI86SQ44BE-IS2R uniquely integrates QSPI-optimized direction control, 150 Mbps speed, and AEC-Q100 Grade 1 qualification - making it the only drop-in solution for automotive-grade isolated memory interfaces requiring runtime bus reversal.

Availability

SI86SQ44BE-IS2R is available at Aetrix Electronics and suitable for onboard chargers, battery management systems, and traction inverter control requiring stable component supply across automotive production lifecycles.

Supply support for SI86SQ44BE-IS2R 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 Si86Sxx family was designed specifically for high-reliability isolation in automotive electrification and industrial automation, emphasizing reinforced safety certification, wide temperature operation, and protocol-aware features like QSPI direction control.

FAQ

What is the isolation rating and safety certification status of the SI86SQ44BE-IS2R?

The SI86SQ44BE-IS2R provides 6000 VRMS reinforced isolation per UL 1577 (1 minute), and is certified to VDE 60747-17, CQC GB4943.1, and CSA 62368-1. It carries AEC-Q100 Grade 1 qualification for automotive use. These certifications are fully documented in Skyworks' official safety reports and apply directly to the SI86SQ44BE-IS2R part number in its WB SOIC-16 package.

How does the DIR and ISO_DIR functionality work in the SI86SQ44BE-IS2R?

In the SI86SQ44BE-IS2R, the DIR pin (pin 7) is a side-A input that globally sets signal direction for all four bidirectional channels: high = A→B, low = B→A. The ISO_DIR pin (pin 9) is a side-B output that mirrors the DIR state across the isolation barrier, enabling synchronized logic on the isolated side. This eliminates need for external direction latching or arbitration logic.

Does the SI86SQ44BE-IS2R require external bypass capacitors, and if so, what values?

Yes, the SI86SQ44BE-IS2R requires two bypass capacitors per supply rail: a 0.1 µF ceramic capacitor and a 10 µF bulk capacitor placed between VDD1/GND1 and VDD2/GND2 respectively. Skyworks specifies these values in the datasheet Section 3.2.1 and recommends placement within 3 mm of the respective pins to ensure stable operation and noise immunity.

What fail-safe behavior does the "-BE" suffix indicate for the SI86SQ44BE-IS2R?

The "-BE" suffix denotes the fail-safe option where outputs default to logic high when side-A (VDD1) is unpowered but side-B (VDD2) remains active. This behavior is hard-coded into the silicon and verified in Table 6 of the datasheet. It ensures defined control states during brown-out conditions in critical automotive subsystems.

Can the SI86SQ44BE-IS2R be used for standard SPI, or is it limited to QSPI applications?

The SI86SQ44BE-IS2R supports both standard SPI and QSPI protocols. Its four bidirectional channels and DIR/ISO_DIR architecture are optimized for QSPI's four-data-line half-duplex operation, but the same pins can isolate conventional SPI MOSI/MISO/SCLK/CS signals. The device's 150 Mbps rating exceeds typical SPI speeds, making it backward-compatible without derating.