Skyworks Solutions Inc. SI8642AB-AS

Overview

SI8642AB-AS from Skyworks is a quad-channel digital isolator with 2 input channels on VDD1 side and 2 output channels on VDD2 side, supporting up to 150 Mbps data rate, <10 ns propagation delay, and 2.5 kV RMS isolation rating in a wide-body SOIC-16 package. It operates from 2.5–5.5 V supplies, features Schmitt-trigger inputs for noise immunity, and implements selectable fail-safe mode (default low output) for power-loss scenarios in industrial motor control and isolated ADC interfaces.

For engineers reviewing the SI8642AB-AS datasheet, SI8642AB-AS pinout, SI8642AB-AS application, or SI8642AB-AS equivalent, key selection criteria include its 2:2 channel asymmetry, automotive-grade AEC-Q100 qualification, reinforced insulation compliance (VDE 0884-10 basic), and tri-state enable control per output pair-critical for bidirectional bus isolation in battery management systems and traction inverters.

Technical Context

The SI8642AB-AS uses RF-based on/off keying across a semiconductor isolation barrier-eliminating start-up initialization and enabling robust noise immunity without optical degradation. Its dual-enable architecture (EN1 controls A3/A4; EN2 controls B1/B2) supports independent tri-state control of each 2-channel group.

It delivers precise timing with ≤2.5 ns channel-to-channel skew and ≤4.5 ns propagation delay skew across –40°C to +125°C, while maintaining stable 5.0–13.0 ns propagation delay (tPHL/tPLH) and 5 ns minimum pulse width under full operating conditions.

Key Specifications

Pinout & Package

SI8642AB-AS is housed in a RoHS-compliant wide-body SOIC-16 package (WB SOIC-16, -AS suffix), offering 8 mm creepage and reinforced insulation capability up to 5 kV RMS. The package meets JEDEC reflow Class 3 standards (260 °C peak).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SI8642BB-AS, SI8642AB-AS provides guaranteed low-state fail-safe behavior essential for BMS shutdown paths; versus ADUM2402BRWZ, it delivers 6× higher data rate, automotive qualification, and independent enable control-enabling tighter timing margins and safer fault handling in EV power electronics.

Availability

SI8642AB-AS is available at Aetrix Electronics and suitable for industrial motor control, battery management systems, and traction inverter designs requiring stable component supply, long-term lifecycle support, and AEC-Q100-compliant sourcing.

Supply support for SI8642AB-AS 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 Si864x family was designed specifically for high-reliability, high-speed digital isolation in automotive and industrial power systems-emphasizing low power, precise timing, and safety-certified reinforced insulation.

FAQ

What is the isolation rating and safety certification status of SI8642AB-AS?

SI8642AB-AS is rated for 2.5 kV RMS isolation and certified to UL 1577 (1 minute), CSA Component Notice 5A, and basic VDE 0884-10. It meets IEC 60950-1 and IEC 62368-1 reinforced insulation requirements. The "-AS" suffix confirms wide-body SOIC-16 packaging with 8 mm creepage, enabling use in 400–800 V DC systems without additional spacing.

Does SI8642AB-AS support independent enable control for each channel pair?

Yes, SI8642AB-AS implements two dedicated enable inputs: EN1 controls outputs A3 and A4, while EN2 controls outputs B1 and B2. When either enable is driven low, its associated outputs enter high-impedance state-allowing flexible bus arbitration and power-gating in multi-master SPI or isolated UART configurations without external logic.

What is the default output behavior of SI8642AB-AS during input-side power loss?

SI8642AB-AS is configured with selectable fail-safe mode set to default-low output. When VDD1 drops below UVLO threshold (≤2.325 V), outputs B1 and B2 transition to logic low within 12 ns (tSD), regardless of prior input state. This behavior is hard-coded by ordering option and ensures safe shutdown in battery monitor and motor control safety chains.

Can SI8642AB-AS operate with mismatched supply voltages on VDD1 and VDD2 sides?

Yes, SI8642AB-AS supports independent 2.5–5.5 V supplies on VDD1 and VDD2. It has been characterized with VDD1 = 3.3 V and VDD2 = 5.0 V simultaneously, maintaining full 150 Mbps data rate and <13 ns propagation delay. This enables direct interfacing between 3.3 V microcontrollers and 5 V analog subsystems without level shifters.

Is SI8642AB-AS qualified for automotive applications, and what documentation is available?

Yes, SI8642AB-AS is AEC-Q100 qualified (Grade 1, –40°C to +125°C) and manufactured using full automotive process flows. Skyworks provides AIAG-compliant PPAP documentation, IMDS and CAMDS material declarations, and zero-defect methodology records-supporting Tier-1 supplier audits and ISO/TS 16949 compliance for EV powertrain programs.