Skyworks Solutions Inc. SI8451BA-B-IS1

Overview

SI8451BA-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 worst-case propagation delay <9.5 ns, 0.5 ns channel-to-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 isolation in motor control and isolated ADC interfaces.

For engineers reviewing the SI8451BA-B-IS1 datasheet, SI8451BA-B-IS1 pinout, SI8451BA-B-IS1 application, or SI8451BA-B-IS1 equivalent, this page provides verified specifications, safety-certified isolation parameters, real-world timing performance, and validated alternative options for industrial and automotive signal integrity designs.

Technical Context

The SI8451BA-B-IS1 implements capacitive isolation with on-chip RF modulation/demodulation circuitry, delivering DC-to-150 Mbps bidirectional data transfer without start-up initialization. Its dual-die architecture separates input and output domains, with independent VDD1 and VDD2 supplies enabling level-shifting between 2.70 V and 5.5 V logic domains.

It features an enable pin (EN) that places outputs in high-impedance state within 9.2 ns, supports reinforced insulation per IEC 60747-5-2 and UL 1577 (2500 VRMS), and maintains stable timing across –40 °C to +125 °C at full data rate - critical for power inverter gate drive feedback loops and isolated sensor interfaces.

Key Specifications

Pinout & Package

SI8451BA-B-IS1 uses 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 by notch or dot; pins 1–8 form primary side (VDD1 domain), pins 9–16 form secondary side (VDD2 domain).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADUM141D1BRZ and ISO6741QDWR, SI8451BA-B-IS1 uniquely delivers five 150 Mbps channels with sub-10 ns propagation delay, 0.5 ns skew, and full –40 °C to +125 °C operation - making it the only option qualified for high-bandwidth, thermally demanding motor control and EV power converter designs.

Availability

SI8451BA-B-IS1 is available at Aetrix Electronics and suitable for industrial automation PLCs, hybrid electric vehicle power converters, and isolated ADC/DAC interfaces requiring stable component supply, long-term lifecycle support, and certified 2500 VRMS isolation performance.

Supply support for SI8451BA-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 U.S.-based semiconductor company specializing in analog and mixed-signal connectivity solutions, with leadership in RF, timing, and isolation technologies for high-reliability applications.

The Si84xx family was engineered specifically for high-speed, low-power galvanic isolation in industrial, automotive, and energy infrastructure systems - emphasizing timing precision, safety certification, and robustness under extreme EMI and thermal stress.

FAQ

What is the maximum operating temperature for SI8451BA-B-IS1 at full 150 Mbps data rate?

The SI8451BA-B-IS1 is fully specified for continuous operation at –40 °C to +125 °C ambient temperature while sustaining 150 Mbps data rate across all five channels. This rating is validated per Table 1 in the datasheet under 15 pF loading and 5 V supply conditions, making it suitable for under-hood automotive and high-temperature industrial environments where thermal derating is not required.

Does SI8451BA-B-IS1 require external pull-up or pull-down resistors on its input pins?

No, SI8451BA-B-IS1 does not require external pull-up or pull-down resistors on IN1–IN5 pins. Its CMOS inputs have defined VIH (≥2.0 V) and VIL (≤0.8 V) thresholds across the full 2.70–5.5 V VDD1 range, and internal input structure ensures valid logic states without external biasing - simplifying PCB layout and reducing BOM count.

How does the enable (EN) pin function on SI8451BA-B-IS1?

The EN pin on SI8451BA-B-IS1 is an active-high control that places all five OUTx pins into high-impedance state within 9.2 ns (max) of EN deassertion. When asserted, outputs reflect input states with typical 6 ns propagation delay. This feature enables dynamic bus sharing, power sequencing, and safe startup/shutdown in isolated communication links using SI8451BA-B-IS1.

What safety certifications apply to SI8451BA-B-IS1 and what do they cover?

SI8451BA-B-IS1 holds UL 1577 (2500 VRMS, 1 min), CSA Component Acceptance Notice 5A (IEC 60950-1/61010-1), and VDE 0884-2 (IEC 60747-5-2) certifications. These validate its reinforced insulation capability, including 4.01 mm creepage and 4.9 mm clearance in the SOIC-16 NB package, and confirm suitability for industrial equipment and EV subsystems requiring certified galvanic isolation.

Can SI8451BA-B-IS1 operate with different supply voltages on primary and secondary sides?

Yes, SI8451BA-B-IS1 supports independent VDD1 (2.70–5.5 V) and VDD2 (2.70–5.5 V) supplies, enabling true level-shifting isolation. For example, it can translate 3.3 V SPI signals from a microcontroller (VDD1 = 3.3 V) to 5 V logic levels for an isolated gate driver (VDD2 = 5 V), with no timing penalty or additional components required - a key advantage over optocoupler-based solutions.