Skyworks Solutions Inc. SI8451AA-B-IS1

Overview

SI8451AA-B-IS1 from Skyworks Solutions is a five-channel, ultra-low-power digital isolator in a 16-pin narrow-body SOIC package, supporting up to 150 Mbps data rate with <9.5 ns worst-case propagation delay, 0.5 ns channel-channel skew, and 25 kV/µs common-mode transient immunity. It operates across 2.70–5.5 V supply rails and delivers <8.6 mA per channel at 100 Mbps (5 V), enabling high-speed isolated communication in motor control and industrial power inverters.

For engineers reviewing the SI8451AA-B-IS1 datasheet, SI8451AA-B-IS1 pinout, SI8451AA-B-IS1 application, or SI8451AA-B-IS1 equivalent, this page provides verified specifications, safety-certified isolation parameters, real-world timing performance, and validated alternative options for industrial and automotive subsystem design.

Technical Context

The SI8451AA-B-IS1 implements capacitive isolation using on-chip RF modulation/demodulation, eliminating magnetic coupling and startup initialization. Its dual-supply architecture (VDD1/VDD2) supports independent 2.70–5.5 V operation on each side, enabling level-shifting between logic domains without external components.

It features integrated enable control per channel group, precise timing with ≤1.5 ns pulse width distortion, and reinforced insulation certified to UL 1577 (2500 VRMS), CSA IEC 60950-1/61010-1, and VDE IEC 60747-5-2 - all validated for 60-year lifetime at rated working voltage.

Key Specifications

Pinout & Package

SI8451AA-B-IS1 is housed in a 16-pin narrow-body SOIC (SOIC-16 NB) package with 1.27 mm pitch, 10.3 mm × 7.5 mm footprint, and 2.35 mm max height. Pin 1 marked with dot; pins 1–8 form primary-side interface, pins 9–16 secondary-side.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADUM141D1BRZ and ISO6741FDWR, SI8451AA-B-IS1 uniquely offers five channels with dual enable control, 150 Mbps speed, and sub-10 ns propagation delay - making it optimal for complex industrial motion control where channel count, timing precision, and dynamic power management are jointly critical.

Availability

SI8451AA-B-IS1 is available at Aetrix Electronics and suitable for industrial motor control, isolated switch-mode supplies, and automotive onboard charger designs requiring stable component supply, long-lifecycle assurance, and safety-certified isolation performance.

Supply support for SI8451AA-B-IS1 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 Si84xx family was designed specifically for high-reliability industrial and automotive isolation needs - delivering ultra-low power, precise timing, and regulatory-compliant reinforced insulation in compact SOIC packages.

FAQ

What is the maximum data rate supported by SI8451AA-B-IS1?

The SI8451AA-B-IS1 supports a maximum data rate of 150 Mbps under typical operating conditions (VDD = 5 V, TA = 25 °C). This is confirmed in Table 3 of the datasheet for Si845xBx variants, and applies directly to SI8451AA-B-IS1 as a B-grade device. At 100 Mbps, it draws 8.6 mA per channel at 5 V, balancing speed and power efficiency for real-time control applications.

Does SI8451AA-B-IS1 require external startup initialization?

No, SI8451AA-B-IS1 requires no startup initialization sequence. Valid output data appears within 40 µs of power application (tSU), as specified in Table 3. This zero-initialization behavior simplifies firmware design and improves system reliability in applications like motor drives where deterministic boot timing is essential. The SI8451AA-B-IS1 achieves this via self-clocking RF isolation architecture.

What safety certifications apply to SI8451AA-B-IS1?

SI8451AA-B-IS1 is certified to UL 1577 (2500 VRMS, 1 min), CSA Component Acceptance Notice 5A (IEC 60950-1/61010-1), and VDE IEC 60747-5-2. These cover reinforced insulation for up to 300 VRMS working voltage and are production-tested to 3.0 kVRMS for 1 second. Certification documentation is referenced in Tables 6 and 7 of the official Skyworks datasheet Rev. 1.6.

How many independent enable controls does SI8451AA-B-IS1 provide?

SI8451AA-B-IS1 provides two independent enable inputs: EN1 controls outputs OUT1–OUT3, and EN2 controls OUT4–OUT5. When an enable pin is low, its associated outputs enter high-impedance state (tri-state) with 7–9.2 ns transition time (ten2). This allows dynamic channel gating in systems like modular power converters where subsets of signals must be disabled without resetting the entire isolator.

What is the channel-to-channel timing skew specification for SI8451AA-B-IS1?

The channel-to-channel skew for SI8451AA-B-IS1 is 0.5 ns (typical) and 1.8 ns (maximum), as specified in Table 3 for Si845xBx devices. This parameter measures the variation in propagation delay between any two output channels under identical conditions and is critical for synchronizing multi-signal paths - such as PWM pairs in three-phase inverter gate drivers - where timing mismatch must be minimized.