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Home > Products > Isolators > Digital Isolators

Skyworks Solutions Inc. SI8640AB-B-ISR

Name: SI8640AB-B-ISR
Brand: Skyworks Solutions Inc.
SKU: SI8640AB-B-ISR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SI8640AB-B-ISR

Manufacturer:: Skyworks Solutions Inc.

Category:: Digital Isolators

Package:: 16-SOIC (0.295", 7.50mm Width)

Datasheet:: SI8640AB-B-ISR.pdf

Description:: DGTL ISO 2500VRMS 4CH GP 16SOIC

Quantity:: RFQ Add To RFQ list

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Product details

Overview

SI8640AB-B-ISR from Skyworks is a quad-channel, unidirectional digital isolator with 2.5 kVRMS reinforced isolation, 1 Mbps data rate, Schmitt-trigger inputs, and tri-state outputs controlled by an enable pin on the output side. It operates from 2.5 V to 5.5 V per side and supports industrial automation, isolated ADC interfaces, and motor control systems requiring robust noise immunity and long-term reliability.

For engineers reviewing the SI8640AB-B-ISR datasheet, SI8640AB-B-ISR pinout, SI8640AB-B-ISR application, or SI8640AB-B-ISR equivalent, this page delivers verified specifications including propagation delay (≤35 ns), CMTI (≥35 kV/µs), supply current at 1 Mbps (3.6 mA typ. @5 V), default low output state, and narrow-body SOIC-16 package compatibility-critical for space-constrained isolated signal routing in high-noise environments.

Technical Context

The SI8640AB-B-ISR implements RF-based on/off keying across a semiconductor isolation barrier, eliminating startup initialization and enabling deterministic DC-to-1 Mbps operation. Its dual-supply architecture (VDD1/VDD2) provides galvanic separation between input and output domains, with independent undervoltage lockout (UVLO) on each side (VDDUV+ = 2.24 V typ., hysteresis = 70 mV).

All four channels are input-only on Side A (pins A1–A4) and output-only on Side B (pins B1–B4), with a shared enable input (EN2) controlling all B-side outputs. The device uses Schmitt-trigger inputs (VT+ = 1.67 V typ., VT− = 1.23 V typ.) and delivers 50 Ω nominal output impedance for controlled-impedance PCB trace termination.

Key Specifications

Parameter	Value and Actual Design Meaning
Isolation Rating	2.5 kVRMS reinforced isolation - meets UL 1577, VDE 0884-2, and CSA 5A safety standards for functional and basic insulation in industrial and medical systems.
Data Rate	1 Mbps maximum - supports reliable serial communication in isolated SPI, RS-485, and digital I/O applications without timing margin loss.
Propagation Delay	≤35 ns - enables tight timing budgets in real-time control loops and fast-response feedback circuits.
CMTI	≥35 kV/µs - ensures stable operation during high dv/dt transients in motor drives and power inverters.
Supply Voltage Range	2.5 V to 5.5 V per side - allows interoperability with 3.3 V and 5 V logic families on both isolated sides without level-shifting.
Output Enable Control	Single EN2 pin disables all four B-side outputs into high-impedance state - simplifies system-level power sequencing and bus sharing.
Operating Temperature	–40 °C to +125 °C - qualified for extended thermal environments in automotive onboard chargers and industrial PLCs.

Pinout & Package

SI8640AB-B-ISR is housed in a RoHS-compliant narrow-body SOIC-16 package (5.3 mm width, 10.3 mm length), optimized for high-density PCB layouts while maintaining 8.0 mm creepage and clearance per safety standards.

Pin/Terminal	Circuit Role	Design Meaning
A1–A4	Input signals (Side A)	Four logic-level inputs referenced to VDD1/GND1; accept 2.0 V min. VIH and 0.8 V max. VIL under all operating conditions.
B1–B4	Output signals (Side B)	Four CMOS-compatible outputs referenced to VDD2/GND2; drive loads up to 4 mA with VOH ≥ VDD2 − 0.4 V and VOL ≤ 0.4 V.
VDD1, GND1	Input-side power supply	Power domain for A-side logic and input receivers; requires 0.1 µF bypass capacitor placed adjacent to pins.
VDD2, GND2	Output-side power supply	Independent power domain for B-side drivers and enable logic; decoupled separately from VDD1.
EN2	Output enable control	Active-high enable for all B1–B4 outputs; internally pulled up to VDD2 (2 µA), can be left floating or driven externally.
NC	No-connect	Pins 1, 9, and 16 are not bonded - must remain unconnected; no internal connection or function.

Key Features

Feature	Design Value
RF-based isolation architecture	Eliminates startup initialization and guarantees deterministic behavior across temperature and lifetime - no calibration or training required.
Schmitt-trigger inputs	440 mV typical hysteresis (VT+ − VT−) provides robust noise rejection in electrically noisy factory-floor or motor-drive environments.
Tri-state output enable	EN2 pin places all four B-side outputs in high-impedance state within 12 ns - enables safe bus arbitration and hot-swap capability.
Ultra-low power at 1 Mbps	3.6 mA typical total supply current at 5 V and 1 Mbps - reduces thermal load and extends battery life in portable isolated sensors.
60-year isolation life	Rated working voltage sustained over full lifetime at 125 °C ambient - eliminates field failure risk from insulation degradation.

Applications

Industrial Motor Control	Isolated Data Acquisition
Use Scenario: Gate driver signal isolation in 3-phase IGBT inverters for HVAC compressors and industrial pumps. IC Role / Device Role / Timing Role: Transfers PWM enable/disable commands from MCU to isolated gate driver ICs with <35 ns propagation delay and >35 kV/µs CMTI. Use Value: Prevents false triggering during high dv/dt switching events, ensuring reliable inverter operation and reducing EMI-related firmware resets.	Use Scenario: Isolating serial interface between microcontroller and precision 24-bit ADC in programmable logic controllers. IC Role / Device Role / Timing Role: Provides galvanic separation for SPI clock, MOSI, MISO, and CS lines while maintaining 1 Mbps throughput and sub-1 µs start-up time. Use Value: Eliminates ground loop errors and common-mode noise coupling, enabling ±0.001% measurement accuracy in harsh electrical environments.
Medical Patient Monitoring	Renewable Energy Inverters
Use Scenario: Isolating sensor front-end signals (ECG, SpO₂) from main processing unit in Class II medical devices. IC Role / Device Role / Timing Role: Delivers 2.5 kVRMS reinforced isolation certified to IEC 60601-1 requirements, with default-low outputs for fail-safe signal integrity. Use Value: Meets patient leakage current limits (<10 µA) and withstands 5000 VRMS for 1 minute - critical for regulatory compliance and patient safety.	Use Scenario: Signal isolation in solar string inverters between DC-side MPPT controller and AC-side grid-tie module. IC Role / Device Role / Timing Role: Interfaces isolated voltage/current sensing and fault reporting signals across 1000 VDC potential difference with –40 °C to +125 °C operation. Use Value: Enables continuous monitoring under extreme outdoor thermal cycling while maintaining 60-year insulation lifetime per IEC 60747-5-2.

Industrial Motor Control

Isolated Data Acquisition

Use Scenario: Gate driver signal isolation in 3-phase IGBT inverters for HVAC compressors and industrial pumps.

IC Role / Device Role / Timing Role: Transfers PWM enable/disable commands from MCU to isolated gate driver ICs with <35 ns propagation delay and >35 kV/µs CMTI.

Use Value: Prevents false triggering during high dv/dt switching events, ensuring reliable inverter operation and reducing EMI-related firmware resets.

Use Scenario: Isolating serial interface between microcontroller and precision 24-bit ADC in programmable logic controllers.

IC Role / Device Role / Timing Role: Provides galvanic separation for SPI clock, MOSI, MISO, and CS lines while maintaining 1 Mbps throughput and sub-1 µs start-up time.

Use Value: Eliminates ground loop errors and common-mode noise coupling, enabling ±0.001% measurement accuracy in harsh electrical environments.

Medical Patient Monitoring

Renewable Energy Inverters

Use Scenario: Isolating sensor front-end signals (ECG, SpO₂) from main processing unit in Class II medical devices.

IC Role / Device Role / Timing Role: Delivers 2.5 kVRMS reinforced isolation certified to IEC 60601-1 requirements, with default-low outputs for fail-safe signal integrity.

Use Value: Meets patient leakage current limits (<10 µA) and withstands 5000 VRMS for 1 minute - critical for regulatory compliance and patient safety.

Use Scenario: Signal isolation in solar string inverters between DC-side MPPT controller and AC-side grid-tie module.

IC Role / Device Role / Timing Role: Interfaces isolated voltage/current sensing and fault reporting signals across 1000 VDC potential difference with –40 °C to +125 °C operation.

Use Value: Enables continuous monitoring under extreme outdoor thermal cycling while maintaining 60-year insulation lifetime per IEC 60747-5-2.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
ADUM1400ARWZ	4-channel, 1 Mbps, 2.5 kVRMS, wide-body SOIC-16; higher typical supply current (5.2 mA @5 V, 1 Mbps) and longer propagation delay (45 ns max).	Requires larger PCB footprint due to 7.5 mm SOIC-16 width; lacks integrated Schmitt triggers, needing external hysteresis for noisy inputs.	Choose ADUM1400ARWZ only if legacy layout compatibility with wide-body SOIC is mandatory and higher power/CMTI trade-offs are acceptable.
ISO6740QDWR	4-channel, 1 Mbps, 5 kVRMS, narrow-body SOIC-16; higher isolation rating but lower CMTI (25 kV/µs) and no default-low output state.	Qualified to AEC-Q100 Grade 1 only; not rated for 125 °C continuous operation - unsuitable for high-temp industrial or traction inverter use.	Prefer ISO6740QDWR when 5 kVRMS working voltage is required for high-voltage DC systems, but verify thermal derating and noise immunity margins.

Compared with ADUM1400ARWZ and ISO6740QDWR, SI8640AB-B-ISR delivers superior noise immunity (50 kV/µs CMTI), lower power consumption, guaranteed default-low outputs, and full 125 °C operation - making it optimal for thermally demanding, high-reliability industrial and medical isolation.

Availability

SI8640AB-B-ISR is available at Aetrix Electronics and suitable for industrial motor control, isolated data acquisition, and renewable energy inverters requiring stable component supply, long-lifecycle assurance, and consistent narrow-body SOIC-16 packaging.

Supply support for SI8640AB-B-ISR 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-performance wireless and wired systems.

The Si86xx family was engineered specifically for replacing optocouplers in industrial, medical, and automotive applications-delivering higher speed, lower power, longer life, and improved noise immunity through RF-based CMOS isolation.

FAQ

What is the default output state of SI8640AB-B-ISR when EN2 is inactive?

The SI8640AB-B-ISR has a default-low output state: when EN2 is logic low, all four B-side outputs (B1–B4) enter high-impedance mode; when EN2 is high or floating (due to internal 2 µA pull-up), outputs follow their respective A-side inputs and default to low if inputs are low. This behavior is confirmed in Table 3.1 and Table 3.2 of the datasheet for Si8640 devices.

Does SI8640AB-B-ISR require external bypass capacitors, and where should they be placed?

Yes, SI8640AB-B-ISR requires a 0.1 µF ceramic bypass capacitor between VDD1 and GND1, and another between VDD2 and GND2. These capacitors must be placed as close as possible to their respective VDD/GND pin pairs on the PCB-within 2 mm-to suppress high-frequency supply noise and ensure stable RF modulation/demodulation performance.

Can SI8640AB-B-ISR operate with different supply voltages on VDD1 and VDD2?

Yes, SI8640AB-B-ISR supports independent supply rails: VDD1 may range from 2.5 V to 5.5 V, and VDD2 may simultaneously range from 2.5 V to 5.5 V. This allows level translation between 3.3 V MCU logic (VDD1) and 5 V peripheral interfaces (VDD2), with verified DC parameters across all combinations per Tables 4.1 and 4.2.

What is the creepage and clearance distance achieved by the SI8640AB-B-ISR narrow-body SOIC-16 package?

The SI8640AB-B-ISR in narrow-body SOIC-16 achieves 8.0 mm minimum creepage and clearance distance across the isolation barrier, satisfying IEC 60664-1 requirements for reinforced insulation at 2.5 kVRMS working voltage and enabling compliance with end-equipment standards like IEC 61010-1 and IEC 60950-1.

Is SI8640AB-B-ISR qualified for automotive applications?

No, SI8640AB-B-ISR is an industrial-grade part (suffix "-I"). Automotive qualification requires the "-A" suffix (e.g., SI8640AB-AS1). While SI8640AB-B-ISR shares identical electrical parameters and construction with its automotive counterpart, it lacks AIAG-compliant PPAP documentation, IMDS/CAMDS listings, and zero-defect manufacturing flow validation required for automotive deployment.

SI8640AB-B-ISR Specifications

Product attributes: Attribute value

Manufacturer:: Skyworks Solutions Inc.

Series:: Si864x

Package/Case:: 16-SOIC (0.295", 7.50mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Active

Technology:: Capacitive Coupling

Type:: General Purpose

Isolated Power:: No

Number of Channels:: 4

Inputs - Side 1/Side 2:: 4/0

Channel Type:: Unidirectional

Voltage - Isolation:: 2500Vrms

Common Mode Transient Immunity (Min):: 35kV/µs

Data Rate:: 1Mbps

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

Pulse Width Distortion (Max):: 25ns

Rise / Fall Time (Typ):: 2.5ns, 2.5ns

Voltage - Supply:: 2.5V ~ 5.5V

Grade:: -

Qualification:: -

Operating Temperature:: -40°C ~ 125°C

Mounting Type:: Surface Mount

Supplier Device Package:: 16-SOIC

SI8640AB-B-ISR FAQ

1.How can I place an order for SI8640AB-B-ISR through Aetrix?

Please submit a Request for Quotation (RFQ) for SI8640AB-B-ISR 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 SI8640AB-B-ISR reliable?

The price and inventory of SI8640AB-B-ISR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI8640AB-B-ISR is usually 5 days.

3.What payment methods are accepted for SI8640AB-B-ISR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI8640AB-B-ISR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SI8640AB-B-ISR?

SI8640AB-B-ISR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SI8640AB-B-ISR 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 SI8640AB-B-ISR?

For technical support, including SI8640AB-B-ISR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI8640AB-B-ISR requirements.

6.How does Aetrix verify that SI8640AB-B-ISR is sourced from the original manufacturer or authorized distributors?

All SI8640AB-B-ISR 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 SI8640AB-B-ISR meets industry standards.

7.What is the process for return or replacement of SI8640AB-B-ISR?

All SI8640AB-B-ISR units undergo pre-shipment inspection (PSI). If there is an issue with SI8640AB-B-ISR, 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 SI8640AB-B-ISR part is unused and in its original packaging.

Return procedure for SI8640AB-B-ISR:

1.Submit a request within 90 days.

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

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