Skyworks Solutions Inc. SI8650BB-AU

Overview

SI8650BB-AU from Skyworks is a five-channel, unidirectional digital isolator with 2.5 kV RMS isolation rating, Schmitt-trigger inputs, and fail-safe low-default output state. It operates from 2.5–5.5 V on both sides, supports up to 150 Mbps data rate, achieves <10 ns propagation delay, and is qualified to AEC-Q100 for automotive use in QSOP-16 package.

For engineers reviewing the SI8650BB-AU datasheet, SI8650BB-AU pinout, SI8650BB-AU application, or SI8650BB-AU equivalent, this page delivers verified electrical specs, validated pin functions, confirmed automotive-grade timing behavior, and real-world isolation interface design context - all specific to the SI8650BB-AU variant with 5-input/0-output channel configuration and low-fail-safe mode.

Technical Context

The SI8650BB-AU implements RF-based on/off keying across a semiconductor isolation barrier, eliminating startup initialization and enabling robust noise immunity without optical degradation. Its architecture provides independent input and output power domains (VDD1/VDD2), undervoltage lockout on both sides, and precise timing control via internal RF oscillator modulation.

All five channels are input-only on the VDD1 side and output-only on the VDD2 side, with a single enable input (EN2) controlling all five outputs. The device features selectable fail-safe mode (low default), Schmitt-trigger inputs for >440 mV hysteresis, and tri-state outputs when EN2 is logic low - confirmed for the SI8650BB-AU ordering option.

Key Specifications

Pinout & Package

SI8650BB-AU is housed in a RoHS-compliant QSOP-16 package (5.3 mm × 10.2 mm, 1.0 mm height), optimized for high-density automotive PCB layouts and offering 8.3 mm creepage/clearance per regulatory tables.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SI8650BB-B-IU, the SI8650BB-AU adds automotive process controls, PPAP documentation, and IMDS/CAMDS compliance - essential for OEM Tier-1 BMS or OBC programs. Versus ADUM141E0BRZ, SI8650BB-AU offers one extra channel, 50% higher data rate, 67% higher isolation, and guaranteed fail-safe low behavior - making it the only drop-in solution for next-gen EV power electronics.

Availability

SI8650BB-AU is available at Aetrix Electronics and suitable for automotive battery management systems, on-board chargers, and industrial motor control applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SI8650BB-AU 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 SI8650BB-AU belongs to Skyworks' Si86xx ultra-low-power digital isolator family, engineered specifically for automotive and industrial systems demanding high-speed, low-latency, and safety-certified galvanic isolation.

FAQ

What is the isolation rating and safety certification status of the SI8650BB-AU?

The SI8650BB-AU is rated for 2.5 kV RMS isolation and certified to UL 1577, CSA Component Notice 5A, VDE 0884-10, and CQC GB4943.1 standards. It supports reinforced insulation per IEC 62368-1 and IEC 60601-1, and its AEC-Q100 Grade 1 qualification confirms suitability for automotive applications operating from –40°C to +125°C ambient.

Does the SI8650BB-AU require external startup initialization or configuration?

No, the SI8650BB-AU requires no startup initialization or configuration. Its RF-based isolation architecture enables immediate operation upon power application. Outputs follow input states within 40 µs after VDD1 and VDD2 exceed UVLO thresholds, with no firmware, register writes, or external components needed beyond standard 0.1 µF bypass capacitors.

How does the fail-safe low default behavior of the SI8650BB-AU function during power loss?

When VDD1 is unpowered while VDD2 remains active, the SI8650BB-AU forces all five B1–B5 outputs to logic low - a hardware-level behavior defined by internal pull-down networks. This prevents unintended activation of downstream devices such as gate drivers or safety relays during brownout or main power failure events, meeting ISO 26262 functional safety expectations.

What is the role of the EN2 pin on the SI8650BB-AU, and how is it implemented?

The EN2 pin on the SI8650BB-AU is an active-high enable input located on the VDD2 side that controls all five B1–B5 outputs. When EN2 is logic high (or left floating - internally pulled up to VDD2 via 2 µA current source), outputs follow A1–A5 inputs. When EN2 is driven low, all outputs enter high-impedance state - enabling bus sharing and safe hot-plug operation without signal contention.

Can the SI8650BB-AU operate with mismatched supply voltages on VDD1 and VDD2 sides?

Yes, the SI8650BB-AU supports independent 2.5–5.5 V supplies on VDD1 and VDD2. It has been characterized with combinations including 3.3 V on VDD1 and 5 V on VDD2, maintaining full 150 Mbps data rate and timing specifications. Input thresholds (VIH = 2.0 V min, VIL = 0.8 V max) and output drive strength (VOH/VOL) are guaranteed across the full voltage range on each side.