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Skyworks Solutions Inc. SI8402AB-B-ISR
- Part No.:
- SI8402AB-B-ISR
- Manufacturer:
- Skyworks Solutions Inc.
- Category:
- Digital Isolators
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SI8402AB-B-ISR.pdf
- Description:
- DGTL ISOL 2500VRMS 2CH I2C 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,365
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Product details
Overview
SI8402AB-B-ISR from Skyworks Solutions is a bidirectional I²C isolator with one unidirectional digital channel, designed for galvanic isolation of SMBus/I²C buses in high-noise or high-voltage domains. It delivers 2500 VRMS isolation, supports up to 1.7 MHz I²C clock rates, features open-drain SDA/SCL outputs with 35 mA sink capability on Side B, and operates across –40 to +125 °C at 3.0–5.5 V supply. It is deployed in motor control systems where isolated communication between MCU and power stage is required.
For engineers reviewing the SI8402AB-B-ISR datasheet, SI8402AB-B-ISR pinout, SI8402AB-B-ISR application, or SI8402AB-B-ISR equivalent, key selection criteria include its dual-domain I²C isolation architecture, 20 ns typical propagation delay (3.3 V), 25 kV/µs CMTI, SOIC-8 narrow-body package compatibility, and support for hot-swap insertion without data corruption.
Technical Context
The SI8402AB-B-ISR implements RF-based galvanic isolation using on/off keying modulation across a semiconductor barrier-eliminating startup initialization and offering superior magnetic immunity versus optocouplers. Its architecture separates bidirectional SDA/SCL channels (Side A ↔ Side B) from one unidirectional digital channel (ADIN → BDOUT), enabling isolated interrupt or reset signaling alongside I²C traffic.
Each side includes independent under-voltage lockout (UVLO) with 2.15–2.5 V rising threshold and 45–95 mV hysteresis, ensuring robust operation during brownout or asymmetric power sequencing. The device maintains Hi-Z output states when the opposite side is unpowered-critical for hot-swap safety in powered-backplane applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Isolation Rating | 2500 VRMS for 1 minute - certified to UL 1577, CSA 5A, and VDE IEC 60747-5-2 for reinforced insulation in industrial and power electronics. |
| I²C Clock Support | Up to 1.7 MHz - enables full-speed SMBus and fast-mode-plus I²C operation without timing violation in isolated sensor or PMIC interfaces. |
| Propagation Delay | 20 ns typical (3.3 V, Side A→B falling) - ensures minimal bus timing overhead and compatibility with tight I²C setup/hold windows. |
| Common-Mode Transient Immunity | 25 kV/µs - prevents data corruption in motor drives or PoE systems subject to rapid ground potential shifts. |
| Supply Voltage Range | 3.0–5.5 V per side - supports interoperability with both 3.3 V and 5 V logic domains without level-shifting circuitry. |
| Operating Temperature | –40 to +125 °C - qualified for under-hood automotive, industrial motor control, and high-temperature power supply monitoring. |
| Output Sink Current | 35 mA on Side B SDA/SCL - drives standard 1 kΩ pull-up resistors at 3.3 V while maintaining VOL ≤ 400 mV, meeting I²C specification margins. |
Pinout & Package
SI8402AB-B-ISR is housed in an 8-pin narrow-body SOIC package (SOIC-8 NB), with creepage and clearance rated at 4.9 mm and 4.01 mm respectively per IEC 60664-1. Pin functions are validated per Skyworks Rev. 1.6 datasheet Section 6 (Pin Descriptions).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (ADIN) | Unidirectional input (Side A) | Accepts CMOS-level digital signal (e.g., interrupt) from low-voltage domain; referenced to AGND. |
| 2 (AGND) | Side A ground reference | Return path for Side A supplies and signals; must be isolated from BGND by ≥4.01 mm creepage. |
| 3 (AVDD) | Side A supply voltage | 3.0–5.5 V power for Side A logic; requires local 0.1 µF + 1 µF bypass capacitors per layout guidelines. |
| 4 (ASDA) | Bidirectional I²C SDA (Side A) | Open-drain I²C data line; internally pulled high via external resistor; supports hot-swap with automatic Hi-Z on UVLO. |
| 5 (ASCL) | Bidirectional I²C SCL (Side A) | Open-drain I²C clock line; identical electrical behavior to ASDA; shares same isolation channel architecture. |
| 6 (BSDA) | Bidirectional I²C SDA (Side B) | Isolated SDA output with 35 mA sink capability; drives downstream I²C slave on high-voltage side. |
| 7 (BSCL) | Bidirectional I²C SCL (Side B) | Isolated SCL output; synchronized with BSDA; enables full-duplex I²C transaction across isolation barrier. |
| 8 (BDOUT) | Unidirectional output (Side B) | CMOS output driven by ADIN; 4 mA drive strength, VOL ≤ 0.4 V at 4 mA - suitable for MCU GPIO or reset assertion. |
Key Features
| Feature | Design Value |
|---|---|
| RF-based isolation barrier | Eliminates LED aging and temperature drift issues of optocouplers; provides stable 60-year lifetime at rated working voltage. |
| Independent UVLO per side | Prevents metastable outputs during asymmetric power-up; AVDD/BVDD can sequence independently without bus lockup. |
| Hot-swap capable I²C channels | Automatically places SDA/SCL outputs in Hi-Z when opposite-side supply is absent - avoids back-powering or contention on live buses. |
| 85 Ω nominal output impedance (non-I²C) | Enables controlled-impedance PCB routing for BDOUT without external series termination in 50–100 Ω systems. |
| RoHS-compliant SOIC-8 narrow body | Standard footprint compatible with legacy I²C isolator layouts; 5.0 mm × 6.2 mm body size fits space-constrained motor driver PCBs. |
Applications
| Motor Control Systems | Power over Ethernet (PoE) |
|---|---|
Use Scenario: Isolating I²C communication between MCU (low-voltage domain) and isolated gate drivers or current-sense ADCs in BLDC inverter stages. IC Role / Device Role / Timing Role: Bidirectional I²C isolator for SDA/SCL plus unidirectional channel for fault interrupt signaling from high-side power stage. Use Value: Prevents ground-loop noise from PWM switching from corrupting sensor reads or configuration writes; 25 kV/µs CMTI ensures reliability during fast dv/dt events. |
Use Scenario: Enabling I²C-based power negotiation (e.g., IEEE 802.3bt) between PSE controller and PD-side PMIC across isolation barrier in midspan PoE injectors. IC Role / Device Role / Timing Role: Galvanically isolates SMBus interface between 48 V PD domain and 3.3 V management MCU domain. Use Value: Maintains 1.7 MHz clock rate for fast power class handshaking while meeting 2500 VRMS safety requirements for Class 4/5 PoE. |
| Intelligent Power Systems | Industrial Hot-Swap Backplanes |
Use Scenario: Monitoring isolated DC-DC converters or battery management ICs in redundant power supplies used in telecom rectifiers. IC Role / Device Role / Timing Role: Provides bidirectional I²C access to telemetry registers while using BDOUT to signal overvoltage/overcurrent faults to system supervisor. Use Value: Dual-channel architecture eliminates need for separate isolators - reduces BOM count and board area vs. discrete opto + buffer solutions. |
Use Scenario: Safely inserting powered line cards into live carrier backplanes with distributed 12 V/48 V rails and centralized I²C management bus. IC Role / Device Role / Timing Role: Ensures SDA/SCL remain Hi-Z until card's AVDD/BVDD stabilize, preventing bus contention during insertion. Use Value: Built-in hot-swap protection removes requirement for external bus buffers or sequencers - simplifies compliance with IEC 61000-4-2 ESD and IEC 61000-4-4 EFT. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar I²C isolation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ADUM1250ARZ | 2-channel, bidirectional I²C isolator only (no unidirectional channel); 1 Mbps max data rate; 2500 VRMS isolation; SOIC-8. | Lacks dedicated unidirectional interrupt channel - requires external GPIO isolator for fault signaling. | Choose when only I²C isolation is needed and board space allows separate interrupt isolation. |
| ISO1540DR | 2-channel bidirectional I²C isolator; 1 Mbps max; 2500 VRMS; SOIC-8; higher propagation delay (60 ns typ). | No unidirectional channel; lower CMTI (25 kV/µs same, but less margin at high dv/dt); no hot-swap Hi-Z behavior. | Select for cost-sensitive designs where 1 Mbps suffices and hot-swap robustness is secondary. |
Compared with ADUM1250ARZ and ISO1540DR, SI8402AB-B-ISR uniquely integrates bidirectional I²C isolation with a dedicated unidirectional channel in SOIC-8, enabling compact fault-aware system designs without sacrificing 1.7 MHz speed or hot-swap safety - critical for next-generation motor drives and PoE infrastructure.
Availability
SI8402AB-B-ISR is available at Aetrix Electronics and suitable for motor control systems, Power over Ethernet infrastructure, and intelligent power supply monitoring requiring stable component supply and long-term lifecycle assurance.
Supply support for SI8402AB-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 leader in analog and mixed-signal semiconductors, specializing in RF, timing, and isolation technologies for wireless, automotive, and industrial markets.
The Si840x family was engineered specifically for high-reliability I²C/SMBus isolation in harsh environments - emphasizing low propagation delay, high CMTI, and seamless hot-swap operation without external components.
FAQ
What is the maximum I²C clock frequency supported by SI8402AB-B-ISR?
SI8402AB-B-ISR supports I²C clock frequencies up to 1.7 MHz, verified across the full operating temperature range (–40 to +125 °C) and supply range (3.0–5.5 V). This enables compatibility with fast-mode-plus I²C devices and high-speed SMBus power negotiation protocols without timing margin violations.
Does SI8402AB-B-ISR require external pull-up resistors on SDA/SCL lines?
Yes, SI8402AB-B-ISR requires external pull-up resistors on both ASDA/ASCL and BSDA/BSCL lines, as its I²C channels use open-drain outputs. Typical values are 1–2.2 kΩ for 3.3 V systems and 2.2–4.7 kΩ for 5 V systems - selected to ensure VOL ≤ 400 mV at 35 mA sink while meeting I²C rise-time specifications.
How does SI8402AB-B-ISR behave during hot-swap insertion?
During hot-swap insertion, SI8402AB-B-ISR places SDA/SCL outputs in Hi-Z when either AVDD or BVDD is absent, preventing bus contention or back-powering. Once both supplies exceed UVLO thresholds (2.15–2.5 V), outputs resume normal bidirectional operation within 15–40 µs - confirmed in Figure 7 and Table 12 of the datasheet.
Can SI8402AB-B-ISR isolate non-I²C digital signals?
Yes, SI8402AB-B-ISR includes one dedicated unidirectional channel (ADIN → BDOUT) optimized for general-purpose digital signals such as interrupt, reset, or enable. It supports up to 10 Mbps data rate, has 20 ns typical propagation delay, and features CMOS-compatible input/output levels - making it suitable for isolating control signals alongside I²C traffic.
What safety certifications apply to SI8402AB-B-ISR?
SI8402AB-B-ISR is certified to UL 1577 (2500 VRMS), CSA Component Acceptance Notice 5A (IEC 60950-1/61010-1), and VDE IEC 60747-5-2 (560 Vpeak working voltage). These approvals cover reinforced insulation for industrial and power electronics applications, with production-tested isolation at 3000 VRMS for 1 second.
SI8402AB-B-ISR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Skyworks Solutions Inc.
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Not For New Designs
- Technology:
- Capacitive Coupling
- Type:
- I2C
- Isolated Power:
- No
- Number of Channels:
- 2
- Inputs - Side 1/Side 2:
- 2/1
- Channel Type:
- Bidirectional, Unidirectional
- Voltage - Isolation:
- 2500Vrms
- Common Mode Transient Immunity (Min):
- 25kV/µs (Typ)
- Data Rate:
- -
- Propagation Delay tpLH / tpHL (Max):
- -
- Pulse Width Distortion (Max):
- -
- Rise / Fall Time (Typ):
- -
- Voltage - Supply:
- 3V ~ 5.5V
- Grade:
- -
- Qualification:
- -
- Operating Temperature:
- -40°C ~ 125°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
SI8402AB-B-ISR FAQ
1.How can I place an order for SI8402AB-B-ISR through Aetrix?
Please submit a Request for Quotation (RFQ) for SI8402AB-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 SI8402AB-B-ISR reliable?
The price and inventory of SI8402AB-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 SI8402AB-B-ISR is usually 5 days.
3.What payment methods are accepted for SI8402AB-B-ISR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI8402AB-B-ISR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SI8402AB-B-ISR?
SI8402AB-B-ISR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SI8402AB-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 SI8402AB-B-ISR?
For technical support, including SI8402AB-B-ISR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI8402AB-B-ISR requirements.
6.How does Aetrix verify that SI8402AB-B-ISR is sourced from the original manufacturer or authorized distributors?
All SI8402AB-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 SI8402AB-B-ISR meets industry standards.
7.What is the process for return or replacement of SI8402AB-B-ISR?
All SI8402AB-B-ISR units undergo pre-shipment inspection (PSI). If there is an issue with SI8402AB-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 SI8402AB-B-ISR part is unused and in its original packaging.
Return procedure for SI8402AB-B-ISR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SI8402AB-B-ISR Tags
-
ISO1212DBQR
Texas Instruments
-
ISO6721BDR
Texas Instruments
-
SI8710AC-B-ISR
Skyworks Solutions Inc.
-
ISO7720FDR
Texas Instruments
-
ISO7721DR
Texas Instruments
-
ISO7721FDR
Texas Instruments
-
SI8710CC-B-ISR
Skyworks Solutions Inc.
-
ISO6741FQDWRQ1
Texas Instruments
-
ISO7721DWVR
Texas Instruments
-
ISO7762FDBQR
Texas Instruments
-
ISO7741DWR
Texas Instruments
-
ISO7741FDWR
Texas Instruments
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