Skyworks Solutions Inc. SI8642BB-AS

Overview

SI8642BB-AS from Skyworks is a quad-channel, 2-input/2-output digital isolator with reinforced 2.5 kV_RMS isolation, 150 Mbps data rate, <10 ns propagation delay, and fail-safe low-default output mode. It operates across 2.5–5.5 V supply rails on both sides and supports industrial and automotive systems requiring high noise immunity and precise timing in isolated gate drivers and power supply feedback loops.

For engineers reviewing the SI8642BB-AS datasheet, SI8642BB-AS pinout, SI8642BB-AS application, or SI8642BB-AS equivalent, this page delivers verified electrical specs, SOIC-16 wide-body package details, tri-state enable control logic, Schmitt-trigger input behavior, and AEC-Q100-qualified alternatives for safety-critical designs.

Technical Context

The SI8642BB-AS implements RF-based on/off keying across a silicon-die isolation barrier, eliminating startup initialization and enabling deterministic sub-10 ns timing. Its dual enable inputs (EN1, EN2) independently control two output pairs (A3/A4 and B1/B2), supporting multiplexed signal routing or clock synchronization without external logic.

Each channel features Schmitt-trigger inputs (1.23 V typical hysteresis), 50 Ω nominal output impedance, and undervoltage lockout (UVLO) on both VDD1 and VDD2 rails-ensuring robust operation during brownout conditions and across –40 to +125 °C ambient temperature.

Key Specifications

Pinout & Package

SI8642BB-AS uses a RoHS-compliant 16-pin wide-body SOIC package (WB SOIC-16, -IS suffix), offering 8 mm creepage and reinforced insulation 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, SI8642BD-AS provides higher isolation margin without layout changes, while ISO6742-Q1 trades speed and skew performance for broader TI toolchain support-making SI8642BB-AS optimal for new designs prioritizing timing precision and noise immunity.

Availability

SI8642BB-AS is available at Aetrix Electronics and suitable for industrial automation systems, battery management systems, and isolated switch-mode power supplies requiring stable component supply, long-term lifecycle assurance, and automotive-grade traceability.

Supply support for SI8642BB-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 for high-reliability applications.

The Si864x family was designed specifically for high-speed, low-power digital isolation in safety-critical power conversion and automotive electrification systems-emphasizing timing accuracy, CMTI robustness, and AEC-Q100 compliance.

FAQ

What is the isolation rating and certification status of SI8642BB-AS?

SI8642BB-AS provides 2.5 kV_RMS reinforced isolation and is certified to UL 1577, CSA Component Acceptance Notice 5A, VDE 0884-10 (basic insulation), and CQC GB4943.1. It meets IEC 62368-1 and IEC 60601-1 requirements for reinforced insulation in industrial and medical end equipment. The "-AS" suffix confirms automotive-grade manufacturing flow and AEC-Q100 qualification.

How does the fail-safe output mode work on SI8642BB-AS?

SI8642BB-AS is ordered with "BB" suffix, indicating a default-low fail-safe mode. When VDD1 is unpowered but VDD2 remains active, outputs A3, A4, B1, and B2 drive logic low within 12 ns (tSD). This behavior prevents undefined states in gate drivers or relay controllers during primary-side power loss-critical for functional safety in motor control and power supply applications.

Can SI8642BB-AS support bidirectional data transfer?

SI8642BB-AS is configured as a 2-input/2-output isolator (A1/A2 → A3/A4; B3/B4 → B1/B2), but full bidirectionality is achievable using external logic. Its pinout and enable architecture allow pairing with complementary isolators or using EN1/EN2 to gate direction-controlled buffers. Unlike dedicated bidirectional isolators, SI8642BB-AS requires external control for true bidirectional SPI or I²C, but its low skew and high CMTI make it ideal for split-direction implementations.

What are the supply current requirements for SI8642BB-AS at 100 Mbps?

At 100 Mbps with 5 V supplies and 15 pF load, SI8642BB-AS draws 11 mA per side (VDD1 and VDD2), totaling 22 mA typical. This ultra-low power consumption-enabled by RF modulation instead of pulse-width encoding-reduces thermal load in dense PCB layouts and extends battery life in portable test equipment or remote sensors using isolated communication.

Does SI8642BB-AS require external components for stable operation?

SI8642BB-AS requires only two 0.1 µF ceramic bypass capacitors-one between VDD1 and GND1, another between VDD2 and GND2-placed adjacent to the package pins. No pull-up/down resistors are needed due to internal Schmitt triggers and fail-safe logic. External series resistors (50–300 Ω) on inputs/outputs are optional and recommended only in exceptionally noisy environments to damp ringing.