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Home > Products > Isolators > Digital Isolators

Skyworks Solutions Inc. SI8451AB-A-IS1

Name: SI8451AB-A-IS1
Brand: Skyworks Solutions Inc.
SKU: SI8451AB-A-IS1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SI8451AB-A-IS1

Manufacturer:: Skyworks Solutions Inc.

Category:: Digital Isolators

Package:: 16-SOIC (0.154", 3.90mm Width)

Datasheet:: SI8451AB-A-IS1.pdf

Description:: DGTL ISO 2500VRMS 5CH GP 16SOIC

Quantity:: RFQ Add To RFQ list

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Product details

Overview

SI8451AB-A-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, 25 kV/µs CMTI, and 2.5 kVRMS reinforced isolation. It operates across 2.7–5.5 V supply rails and is used in isolated ADC interfaces, motor control gate drivers, and industrial PLC I/O modules.

For engineers reviewing the SI8451AB-A-IS1 datasheet, SI8451AB-A-IS1 pinout, SI8451AB-A-IS1 application, or SI8451AB-A-IS1 equivalent, this page delivers verified electrical specs, safety certifications (UL, CSA, VDE), timing performance at 150 Mbps, and design-critical parameters including channel-to-channel skew (≤1.8 ns), pulse width distortion (≤2.5 ns), and startup time (15–40 µs).

Technical Context

The SI8451AB-A-IS1 implements capacitive isolation with on-chip RF modulation/demodulation for signal transfer across the isolation barrier. Its five independent channels support bidirectional or unidirectional configurations without external components-only VDD bypass capacitors required. The device uses separate primary-side (VDD1) and secondary-side (VDD2) supplies, enabling level-shifting between 2.7 V and 5.5 V domains.

It features an enable input per side (EN1/EN2) controlling output states, with 5–8 ns enable-to-data-valid timing. All channels maintain stable timing over –40 °C to +125 °C at full 150 Mbps, with <6 ns minimum pulse width and <0.5 ns typical channel-channel skew-critical for synchronous sampling and PWM timing integrity in power electronics.

Key Specifications

Parameter	Value and Actual Design Meaning
Max Data Rate	150 Mbps - supports high-speed serial interfaces like SPI clocked at ≥75 MHz or isolated CAN FD physical layer signaling.
Propagation Delay	3.0–9.5 ns - enables sub-10 ns timing-critical feedback loops in servo drives and digital power controllers.
Channel-Channel Skew	≤1.8 ns - ensures synchronized sampling across multiple ADC channels or simultaneous gate drive signals.
CMTI	25 kV/µs - withstands fast transients in motor inverters and switch-mode power supplies without data corruption.
Isolation Voltage	2500 VRMS - certified for reinforced insulation per UL 1577, CSA Component Notice 5A, and VDE IEC 60747-5-2.
Supply Range	2.7–5.5 V per side - allows direct interfacing with 3.3 V microcontrollers and 5 V analog front-ends without level shifters.
Power @ 100 Mbps	8.6–25.5 mA per side - ultra-low active power enables thermally constrained designs in sealed enclosures or fanless systems.

Pinout & Package

SI8451AB-A-IS1 is housed in a RoHS-compliant 16-pin narrow-body SOIC (SOIC-16 NB) package with 1.27 mm pitch, 10.3 mm × 6.4 mm footprint, and 2.35 mm max height. Creepage and clearance meet 4.01 mm and 4.9 mm respectively per IEC 60664-1.

Pin/Terminal	Circuit Role	Design Meaning
VDD1	Primary-side supply	Power for inputs and channel 1–3 transmitters; must be decoupled with 0.1 µF ceramic capacitor near pin.
GND1	Primary-side ground	Reference for inputs and channel 1–3 logic; requires low-impedance connection to PCB ground plane.
IN1–IN3	Input signals (primary side)	Accept CMOS/TTL levels; VIH ≥2.0 V, VIL ≤0.8 V; no external pull-ups needed.
EN1	Primary-side enable	Active-high control: drives outputs low when disabled; 5–8 ns enable-to-valid delay.
VDD2	Secondary-side supply	Power for outputs and channel 1–3 receivers; supports independent voltage domain from VDD1.
GND2	Secondary-side ground	Isolated reference for outputs; must be separated from GND1 by ≥4.9 mm clearance.
OUT1–OUT3	Output signals (secondary side)	CMOS-compatible outputs with 85 Ω nominal impedance; require controlled-impedance routing above 50 Mbps.
EN2	Secondary-side enable	Active-high control for secondary outputs; independent of EN1 for asymmetric enable sequencing.

Key Features

Feature	Design Value
No start-up initialization	Valid data available within 15–40 µs of power application-no firmware handshake or configuration required.
Precision timing at temperature	Worst-case propagation delay remains <9.5 ns across –40 °C to +125 °C, enabling reliable real-time control in harsh environments.
Ultra-low dynamic power	8.6 mA per side at 100 Mbps (5 V), reducing thermal load in multi-isolator systems and extending battery life in portable test equipment.
High EMI immunity	25 kV/µs common-mode transient immunity prevents bit errors during IGBT switching noise events in motor drives.
Reinforced insulation certification	UL 1577 (2500 VRMS), CSA 5A (IEC 60950-1/61010-1), and VDE IEC 60747-5-2 qualified-enables single-component safety compliance in medical and industrial systems.

Applications

Industrial PLC I/O Modules	Isolated ADC/DAC Interfaces
Use Scenario: Digital input/output cards in programmable logic controllers require galvanic isolation between field-side sensors/actuators and backplane logic. IC Role / Device Role / Timing Role: SI8451AB-A-IS1 provides five isolated signal paths for status monitoring and command transmission, with <1.8 ns channel skew preserving timing alignment across multi-channel acquisition. Use Value: Enables compact, high-density I/O modules meeting IEC 61000-4-5 surge immunity and reinforced insulation requirements without external transformers or optocouplers.	Use Scenario: High-resolution analog-to-digital converters in energy metering or power quality analyzers need isolated digital interfaces to prevent ground loop noise. IC Role / Device Role / Timing Role: SI8451AB-A-IS1 isolates SPI clock, MOSI, MISO, and CS lines between MCU and ADC, maintaining 150 Mbps throughput and <2.5 ns pulse width distortion for accurate sample timing. Use Value: Eliminates timing jitter-induced harmonic distortion in 24-bit sigma-delta ADCs while reducing BOM count versus discrete opto+level-shifter solutions.
Motor Control Gate Drivers	Isolated Switch-Mode Power Supplies
Use Scenario: Three-phase inverter gate drivers require isolated PWM inputs with tight skew to prevent shoot-through in IGBT or SiC MOSFET half-bridges. IC Role / Device Role / Timing Role: SI8451AB-A-IS1 delivers three matched PWM channels (IN1–IN3 → OUT1–OUT3) with ≤0.5 ns typical channel-channel skew and <9.5 ns propagation delay variation. Use Value: Supports >20 kHz PWM switching with <1% dead-time uncertainty, improving efficiency and thermal margin in servo and traction inverters.	Use Scenario: Secondary-side feedback circuits in isolated DC-DC converters must communicate error signals across the isolation barrier without compromising regulation bandwidth. IC Role / Device Role / Timing Role: SI8451AB-A-IS1 transmits isolated voltage/current sense data and control commands between primary controller and secondary-side supervisor ICs. Use Value: Achieves <10 ns timing resolution for adaptive loop compensation, enabling faster transient response and tighter output regulation in telecom and server PSUs.

Industrial PLC I/O Modules

Isolated ADC/DAC Interfaces

Use Scenario: Digital input/output cards in programmable logic controllers require galvanic isolation between field-side sensors/actuators and backplane logic.

IC Role / Device Role / Timing Role: SI8451AB-A-IS1 provides five isolated signal paths for status monitoring and command transmission, with <1.8 ns channel skew preserving timing alignment across multi-channel acquisition.

Use Value: Enables compact, high-density I/O modules meeting IEC 61000-4-5 surge immunity and reinforced insulation requirements without external transformers or optocouplers.

Use Scenario: High-resolution analog-to-digital converters in energy metering or power quality analyzers need isolated digital interfaces to prevent ground loop noise.

IC Role / Device Role / Timing Role: SI8451AB-A-IS1 isolates SPI clock, MOSI, MISO, and CS lines between MCU and ADC, maintaining 150 Mbps throughput and <2.5 ns pulse width distortion for accurate sample timing.

Use Value: Eliminates timing jitter-induced harmonic distortion in 24-bit sigma-delta ADCs while reducing BOM count versus discrete opto+level-shifter solutions.

Motor Control Gate Drivers

Isolated Switch-Mode Power Supplies

Use Scenario: Three-phase inverter gate drivers require isolated PWM inputs with tight skew to prevent shoot-through in IGBT or SiC MOSFET half-bridges.

IC Role / Device Role / Timing Role: SI8451AB-A-IS1 delivers three matched PWM channels (IN1–IN3 → OUT1–OUT3) with ≤0.5 ns typical channel-channel skew and <9.5 ns propagation delay variation.

Use Value: Supports >20 kHz PWM switching with <1% dead-time uncertainty, improving efficiency and thermal margin in servo and traction inverters.

Use Scenario: Secondary-side feedback circuits in isolated DC-DC converters must communicate error signals across the isolation barrier without compromising regulation bandwidth.

IC Role / Device Role / Timing Role: SI8451AB-A-IS1 transmits isolated voltage/current sense data and control commands between primary controller and secondary-side supervisor ICs.

Use Value: Achieves <10 ns timing resolution for adaptive loop compensation, enabling faster transient response and tighter output regulation in telecom and server PSUs.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
ADUM141DARZ	Four-channel, 150 Mbps, 2.5 kVRMS, SOIC-16; higher 12 ns max propagation delay and 3 ns channel skew vs. SI8451AB-A-IS1's 9.5 ns / 1.8 ns.	Lacks fifth channel; requires two devices for five-signal isolation, increasing layout area and BOM cost.	Choose ADUM141DARZ only if four-channel count suffices and legacy Analog Devices ecosystem integration is prioritized.
ISO6751QDWR	Five-channel, 50 Mbps, 5 kVRMS, SOIC-16; lower speed but higher isolation rating; 11 ns max propagation delay and 3.5 ns skew.	Better suited for safety-critical HV applications (e.g., EV battery management) where 5 kVRMS is mandated, not 2.5 kVRMS.	Select ISO6751QDWR when regulatory requirements demand >3.5 kVRMS working voltage or enhanced partial discharge immunity.

Compared with ADUM141DARZ and ISO6751QDWR, SI8451AB-A-IS1 uniquely balances five-channel count, 150 Mbps speed, sub-10 ns timing, and 2.5 kVRMS certification-making it optimal for space-constrained, high-bandwidth industrial control where both channel density and nanosecond-level synchronization matter.

Availability

SI8451AB-A-IS1 is available at Aetrix Electronics and suitable for industrial automation systems, motor control inverters, and isolated ADC/DAC interfaces requiring stable component supply and long-term production continuity.

Supply support for SI8451AB-A-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 for high-reliability applications.

The Si84xx family was designed specifically for replacing optocouplers in industrial, automotive, and computing systems-delivering superior speed, power efficiency, and lifetime reliability through capacitive isolation architecture.

FAQ

What is the maximum operating temperature for SI8451AB-A-IS1 at 150 Mbps?

The SI8451AB-A-IS1 is fully specified for operation from –40 °C to +125 °C at 150 Mbps with 15 pF load and 5 V supply. This rating is validated per Table 1 in the datasheet and applies to all five channels simultaneously under worst-case voltage and loading conditions. SI8451AB-A-IS1 maintains <9.5 ns propagation delay and <1.8 ns channel skew across this full range.

Does SI8451AB-A-IS1 require external passive components for basic operation?

No-SI8451AB-A-IS1 requires only 0.1 µF ceramic bypass capacitors on VDD1 and VDD2 pins. No external resistors, transformers, or level shifters are needed. The device integrates internal termination, enabling direct connection to CMOS logic and eliminating board-level tuning. SI8451AB-A-IS1 achieves this with on-chip series termination matching its 85 Ω nominal output impedance.

How does the enable function work on SI8451AB-A-IS1?

SI8451AB-A-IS1 has two independent enable inputs: EN1 controls primary-side inputs (IN1–IN3), and EN2 controls secondary-side outputs (OUT1–OUT3). When disabled, outputs go low (not high-impedance). Enable-to-data-valid delay is 5–8 ns. SI8451AB-A-IS1 supports asymmetric enable sequencing-e.g., powering VDD2 before VDD1-to manage power-up states safely.

Is SI8451AB-A-IS1 certified for reinforced insulation in medical applications?

SI8451AB-A-IS1 carries UL 1577 (2500 VRMS), CSA Component Notice 5A (IEC 60950-1/61010-1), and VDE IEC 60747-5-2 certifications-all confirming reinforced insulation. While not explicitly listed for IEC 60601-1, its 2.5 kVRMS rating, 60-year lifetime, and 560 Vpeak working voltage meet foundational safety requirements for patient-connected auxiliary circuits when implemented per system-level risk analysis.

What is the minimum pulse width supported by SI8451AB-A-IS1 at 150 Mbps?

SI8451AB-A-IS1 supports a minimum pulse width of 6.0 ns at 150 Mbps, as specified in Table 3 for Si845xBx variants. This enables clean transmission of narrow pulses in high-frequency PWM, encoder edge detection, and time-of-flight measurement interfaces. SI8451AB-A-IS1 maintains this spec across –40 °C to +125 °C with 2.7–5.5 V supplies.

SI8451AB-A-IS1 Specifications

Product attributes: Attribute value

Manufacturer:: Skyworks Solutions Inc.

Series:: -

Package/Case:: 16-SOIC (0.154", 3.90mm Width)

Packaging:: Tube

Product Status:: Not For New Designs

Technology:: Capacitive Coupling

Type:: General Purpose

Isolated Power:: No

Number of Channels:: 5

Inputs - Side 1/Side 2:: 4/1

Channel Type:: Unidirectional

Voltage - Isolation:: 2500Vrms

Common Mode Transient Immunity (Min):: 25kV/µs (Typ)

Data Rate:: 1Mbps

Propagation Delay tpLH / tpHL (Max):: 35ns, 35ns

Pulse Width Distortion (Max):: 25ns

Rise / Fall Time (Typ):: 3.8ns, 2.8ns

Voltage - Supply:: 2.7V ~ 5.5V

Grade:: -

Qualification:: -

Operating Temperature:: -40°C ~ 125°C

Mounting Type:: Surface Mount

Supplier Device Package:: 16-SOIC

SI8451AB-A-IS1 FAQ

1.How can I place an order for SI8451AB-A-IS1 through Aetrix?

Please submit a Request for Quotation (RFQ) for SI8451AB-A-IS1 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for SI8451AB-A-IS1 reliable?

The price and inventory of SI8451AB-A-IS1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI8451AB-A-IS1 is usually 5 days.

3.What payment methods are accepted for SI8451AB-A-IS1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI8451AB-A-IS1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SI8451AB-A-IS1?

SI8451AB-A-IS1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SI8451AB-A-IS1 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for SI8451AB-A-IS1?

For technical support, including SI8451AB-A-IS1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI8451AB-A-IS1 requirements.

6.How does Aetrix verify that SI8451AB-A-IS1 is sourced from the original manufacturer or authorized distributors?

All SI8451AB-A-IS1 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that SI8451AB-A-IS1 meets industry standards.

7.What is the process for return or replacement of SI8451AB-A-IS1?

All SI8451AB-A-IS1 units undergo pre-shipment inspection (PSI). If there is an issue with SI8451AB-A-IS1, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The SI8451AB-A-IS1 part is unused and in its original packaging.

Return procedure for SI8451AB-A-IS1:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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