Skyworks Solutions Inc. SI86SQ44EE-IS2R

Overview

SI86SQ44EE-IS2R from Skyworks Solutions is a 5-channel reinforced digital isolator with quad-SPI-compatible bidirectional channel control, designed for isolated high-speed serial bus interfaces in automotive and industrial systems. It supports up to 150 Mbps data rate, features 10 ns typical propagation delay, 6000 VRMS isolation rating, and operates across –40 to 125 °C with 2.25–5.5 V dual supply rails.

For engineers reviewing the SI86SQ44EE-IS2R datasheet, SI86SQ44EE-IS2R pinout, SI86SQ44EE-IS2R application, or SI86SQ44EE-IS2R equivalent, key selection considerations include its configurable QSPI-direction logic (DIR/ISO_DIR), tristate enable pins (EN_A/EN_B), fail-safe default output mode, and AEC-Q100 qualification for traction inverters and battery management systems.

Technical Context

The SI86SQ44EE-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 architecture integrates four reversible I/O channels (A1–A4/B1–B4) and one dedicated forward-direction channel (DIR → ISO_DIR), all synchronized by a single DIR input controlling signal flow direction across the barrier.

It supports independent side-A and side-B undervoltage lockout (UVLO+ = 2.18 V, UVLO– = 2.05 V) and reset thresholds (RSTB– ≈ 1.7 V), with 100 kΩ weak pulldown on unpowered I/Os. The device includes Schmitt-trigger inputs, CMOS thresholds, and optional sleep-mode control via external enable pins - though SI86SQ44EE-IS2R does not implement the SMb pin found in SM-series variants.

Key Specifications

Pinout & Package

SI86SQ44EE-IS2R is housed in a wide-body SOIC-16 (WB SOIC-16) package with creepage/clearance optimized for 6000 VRMS reinforced insulation. Pin 1 is marked with a dot; the isolation barrier separates Side A (pins 1–8) and Side B (pins 9–16).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADUM3481BRNZ and ISO6741FDWR, SI86SQ44EE-IS2R uniquely delivers 150 Mbps QSPI-ready bidirectional isolation with 6000 VRMS rating and AEC-Q100 Grade 0 qualification - making it the only option qualified for high-voltage automotive traction inverter control loops.

Availability

SI86SQ44EE-IS2R is available at Aetrix Electronics and suitable for automotive battery management systems, industrial isolated QSPI flash interfaces, motor control gate driver interfaces, and traction inverter current sensing requiring stable component supply and long-term lifecycle support.

Supply support for SI86SQ44EE-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 leader in analog and mixed-signal semiconductors, specializing in RF, timing, and isolation technologies for high-reliability applications.

The Si86Sxx family, including SI86SQ44EE-IS2R, was engineered specifically for automotive and industrial isolation challenges - emphasizing reinforced safety certification, high CMTI, and protocol-aware architectures like QSPI-direction control.

FAQ

What is the isolation voltage rating of the SI86SQ44EE-IS2R and which safety standards does it meet?

The SI86SQ44EE-IS2R provides 6000 VRMS reinforced isolation per UL 1577 for 1 minute and is certified to IEC 60747-17, CSA 62368-1, and CQC GB4943.1. This rating enables use in 600 VAC industrial systems and automotive high-voltage domains up to 800 V DC. All certifications apply directly to the SI86SQ44EE-IS2R part number in its WB SOIC-16 package.

How does the DIR and ISO_DIR functionality work in the SI86SQ44EE-IS2R?

In the SI86SQ44EE-IS2R, the DIR pin (pin 7) is a side-A input that configures all four bidirectional channels (A1–A4/B1–B4) to transmit either A→B (DIR = high) or B→A (DIR = low). The ISO_DIR output (pin 9) replicates this state on side B, enabling synchronized bus arbitration. This eliminates external direction logic and ensures atomic direction switching across all channels - a core feature of the SI86SQ44EE-IS2R.

Does the SI86SQ44EE-IS2R support fail-safe output behavior during power loss?

Yes, the SI86SQ44EE-IS2R offers a factory-configured fail-safe mode where outputs default to logic low when side-A supply is unpowered but side-B remains active. This behavior is implemented in the SI86SQ44EE-IS2R variant and is confirmed in Table 6 of the datasheet for logic states under unpowered VDD1. It ensures safe shutdown in battery management and motor control applications.

What are the supply voltage and bypass capacitor requirements for the SI86SQ44EE-IS2R?

The SI86SQ44EE-IS2R requires 2.25–5.5 V on both VDD1 and VDD2, with 0.1 µF ceramic and 10 µF bulk capacitors placed adjacent to each VDD/GND pair. These values are mandatory per Section 3.2.1 of the datasheet to ensure stable RF modulation and noise immunity. Failure to implement both capacitors risks erratic behavior or reduced CMTI performance in the SI86SQ44EE-IS2R.

Is the SI86SQ44EE-IS2R pin-compatible with other devices in the Si86Sxx family?

No, the SI86SQ44EE-IS2R has a unique pinout optimized for QSPI direction control (e.g., DIR on pin 7, ISO_DIR on pin 9), differing from Si86S64x (enable-only) and Si86SS41 (SPI-specific) variants. Its WB SOIC-16 footprint matches other wide-body Si86Sxx parts, but signal assignments are not interchangeable - PCB layout must be dedicated to the SI86SQ44EE-IS2R.