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Skyworks Solutions Inc. SI8400AB-B-ISR
- Part No.:
- SI8400AB-B-ISR
- Manufacturer:
- Skyworks Solutions Inc.
- Category:
- Digital Isolators
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SI8400AB-B-ISR.pdf
- Description:
- DGTL ISOL 2500VRMS 2CH I2C 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,864
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Product details
Overview
SI8400AB-B-ISR from Skyworks Solutions is a bidirectional I²C isolator with two unidirectional digital channels, designed for galvanic isolation of I²C/SMBus buses in high-noise or high-voltage domains. It delivers 1.7 MHz I²C clock support, 2500 VRMS isolation rating, 3.0–5.5 V dual-supply operation, and open-drain SDA/SCL outputs with 35 mA sink capability on Side B - enabling robust hot-swap and isolated power supply communication in industrial motor control systems.
For engineers reviewing the SI8400AB-B-ISR datasheet, SI8400AB-B-ISR pinout, SI8400AB-B-ISR application, or SI8400AB-B-ISR equivalent, key selection criteria include its SOIC-8 narrow-body package, bidirectional I²C channel architecture, UVLO thresholds (2.3 V typ), propagation delay (≤29 ns at 5 V), and compliance with UL 1577, CSA 5A, and VDE IEC 60747-5-2 safety standards.
Technical Context
The SI8400AB-B-ISR implements RF-based galvanic isolation using on/off keying modulation across a semiconductor barrier, eliminating startup initialization and providing inherent immunity to magnetic fields and EMI. Its dual-side UVLO circuitry (2.3 V threshold, 75 mV hysteresis) ensures deterministic behavior during power sequencing, while independent AVDD/BVDD supplies allow asymmetric voltage operation (e.g., 3.3 V on Side A, 5 V on Side B).
All I²C channels feature open-drain outputs with side-specific logic thresholds: Side A supports 0.45–0.78 V input thresholds and ≤910 mV output low at 3 mA; Side B guarantees ≤400 mV output low at 35 mA sink, enabling direct interface with standard I²C pull-up networks without external level shifting.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| I²C Max Frequency | 1.7 MHz - supports full-speed I²C without bus timing violation under typical 400 pF load conditions. |
| Isolation Rating | 2500 VRMS - certified per UL 1577, CSA 5A, and VDE IEC 60747-5-2 for reinforced insulation in industrial equipment. |
| Supply Voltage Range | 3.0–5.5 V per side - enables interoperability between 3.3 V microcontrollers and 5 V peripheral domains. |
| Propagation Delay | ≤29 ns (A→B rising, 5 V) - ensures sub-100 ns round-trip latency critical for real-time I²C arbitration and ACK timing. |
| Sink Current (Side B) | 35 mA - drives standard 2.2 kΩ pull-ups at 5 V with <0.4 V VOL, eliminating need for external buffer transistors. |
| Common-Mode Transient Immunity | 25 kV/µs - maintains data integrity during fast-switching events in motor drives and PoE systems. |
| Operating Temperature | –40 to +125 °C - qualified for under-hood automotive and industrial ambient environments. |
Pinout & Package
SI8400AB-B-ISR is housed in an 8-pin narrow-body SOIC package (5.3 mm × 6.2 mm, 1.75 mm height) with creepage/clearance ≥4.0 mm and reinforced insulation per IEC 60747-5-2.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (AVDD) | Side A Power Supply | 3.0–5.5 V supply for input-side logic and RF transmitter; requires local 0.1 µF + 1 µF bypass. |
| 2 (ASDA) | Side A Bidirectional SDA | Open-drain I²C data line; interfaces directly to MCU SDA with external pull-up; supports hot-swap insertion. |
| 3 (ASCL) | Side A Bidirectional SCL | Open-drain I²C clock line; synchronized with ASDA for bidirectional bus arbitration and ACK/NACK timing. |
| 4 (AGND) | Side A Ground Reference | Return path for Side A signals; must be isolated from BGND by ≥4.0 mm creepage in PCB layout. |
| 5 (BGND) | Side B Ground Reference | Return path for Side B signals; forms isolation barrier boundary with AGND; defines safety clearance zone. |
| 6 (BSCL) | Side B Bidirectional SCL | Isolated clock output; matches ASCL timing within ≤15 ns pulse-width distortion at 1.7 MHz. |
| 7 (BSDA) | Side B Bidirectional SDA | Isolated data output; sinks up to 35 mA to maintain <0.4 V VOL into 2.2 kΩ pull-up at 5 V. |
| 8 (BVDD) | Side B Power Supply | Independent 3.0–5.5 V supply for output-side logic and RF receiver; enables asymmetric voltage domain bridging. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional I²C Isolation | Preserves native I²C protocol semantics (clock stretching, arbitration, ACK/NACK) without software or hardware translation. |
| RF-Based Isolation Architecture | Eliminates LED aging and temperature drift issues of optocouplers; achieves 60-year life at rated working voltage. |
| Hot-Swap Capability | Protection circuits prevent data corruption when inserting unpowered SI8400AB-B-ISR into live I²C buses. |
| Dual Independent UVLO | Side A and Side B each monitor their own supply; outputs enter safe state if either AVDD or BVDD drops below 2.3 V. |
| Low Propagation Skew | ≤12 ns pulse-width distortion ensures reliable I²C timing margins even at 1.7 MHz maximum frequency. |
Applications
| Industrial Motor Control | Isolated Power Supply Monitoring |
|---|---|
|
Use Scenario: Isolating I²C communication between a 3.3 V MCU and 5 V isolated DC-DC converter monitoring IC in servo drive feedback loops. IC Role / Device Role / Timing Role: Bidirectional I²C isolator maintaining clock/data integrity across 2500 VRMS barrier while supporting 1.7 MHz telemetry updates. Use Value: Enables real-time fault reporting and parameter tuning without compromising safety isolation or violating I²C timing constraints. |
Use Scenario: Connecting host controller to isolated PMBus-compliant DC-DC modules in telecom power shelves. IC Role / Device Role / Timing Role: Galvanically isolating SMBus transactions between primary and secondary sides of isolated power converters. Use Value: Maintains full PMBus command set compatibility (including Write-Only commands) with <30 ns propagation delay. |
| Power over Ethernet (PoE) | Intelligent Power Distribution Units |
|
Use Scenario: Isolating I²C management interface between PSE controller and powered device (PD) in IEEE 802.3af/at systems. IC Role / Device Role / Timing Role: Bidirectional I²C channel bridging primary-side control logic and secondary-side PD classification circuitry. Use Value: Supports hot-swap insertion of PD modules while preserving I²C bus arbitration and preventing ground loop currents. |
Use Scenario: Isolating microcontroller I²C bus from multiple downstream smart breakers and current sensors in rack-level power distribution. IC Role / Device Role / Timing Role: Enabling simultaneous readout of 12+ sensor registers via shared I²C bus across reinforced isolation barriers. Use Value: Eliminates need for separate I²C masters per zone, reducing BOM count and PCB area while meeting IEC 61000-4-5 surge immunity. |
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, 1 Mbps max I²C speed; 2500 VRMS isolation; CMOS input/output; no integrated I²C logic. | Requires external pull-ups and level-shifting for I²C bus compatibility; lacks native SDA/SCL arbitration handling. | Choose ADUM1250ARZ only when custom I²C protocol translation is acceptable and lower cost outweighs design complexity. |
| ISO1540DR | 2-channel, 1 Mbps max I²C speed; 2500 VRMS isolation; integrated I²C logic but no UVLO hysteresis specification. | Limited to 3.3 V operation; no 5 V side-B sink capability; higher typical propagation delay (45 ns). | Select ISO1540DR for 3.3 V-only systems where 1 Mbps bandwidth suffices and thermal derating margin is less critical. |
Compared with ADUM1250ARZ and ISO1540DR, SI8400AB-B-ISR provides native 1.7 MHz I²C support, 35 mA side-B sink strength, and guaranteed UVLO hysteresis - making it optimal for high-speed, mixed-voltage, and hot-swap-critical industrial applications.
Availability
SI8400AB-B-ISR is available at Aetrix Electronics and suitable for industrial motor control, isolated power supply monitoring, and Power over Ethernet applications requiring stable component supply, long-term lifecycle assurance, and certified safety isolation.
Supply support for SI8400AB-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 wireless infrastructure, automotive, and industrial markets.
The Si840x family was engineered specifically for galvanic isolation of I²C and SMBus interfaces in harsh environments, emphasizing RF-based reliability, hot-swap resilience, and regulatory compliance across UL, CSA, and VDE standards.
FAQ
What is the maximum I²C clock frequency supported by the SI8400AB-B-ISR?
The SI8400AB-B-ISR supports a maximum I²C clock frequency of 1.7 MHz, verified across the full operating temperature range (–40 to +125 °C) and supply voltage range (3.0–5.5 V). This enables full-speed I²C operation without timing violations, even under worst-case bus capacitance and pull-up conditions specified in the datasheet test setup.
Does the SI8400AB-B-ISR require external components for basic I²C isolation functionality?
Yes, the SI8400AB-B-ISR requires external pull-up resistors on both ASDA/ASCL and BSDA/BSCL lines to establish valid I²C logic levels, plus 0.1 µF and 1 µF bypass capacitors on AVDD and BVDD pins. No level shifters or protocol translators are needed - the device natively handles I²C bidirectional signaling and arbitration.
How does the SI8400AB-B-ISR handle power loss on one side during operation?
When AVDD or BVDD drops below the UVLO threshold (2.3 V typ), the corresponding side enters a safe state: outputs go high-impedance for I²C channels, preventing bus contention. The SI8400AB-B-ISR resumes normal operation within 40 µs after supply recovery, with no firmware reset required.
Is the SI8400AB-B-ISR pin-compatible with other devices in the Si840x family?
No, the SI8400AB-B-ISR is not pin-compatible with Si8402 or Si8405 variants due to differing channel configurations and pin assignments. It shares the SOIC-8 footprint with Si8401AB-B-ISR but differs in internal routing - always verify pinout against the official Skyworks datasheet Rev. 1.6 before board layout.
What safety certifications apply to the SI8400AB-B-ISR?
The SI8400AB-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 certifications cover reinforced insulation requirements for industrial and medical end-equipment compliance.
SI8400AB-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:
- 2/2
- Channel Type:
- Bidirectional
- 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
SI8400AB-B-ISR FAQ
1.How can I place an order for SI8400AB-B-ISR through Aetrix?
Please submit a Request for Quotation (RFQ) for SI8400AB-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 SI8400AB-B-ISR reliable?
The price and inventory of SI8400AB-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 SI8400AB-B-ISR is usually 5 days.
3.What payment methods are accepted for SI8400AB-B-ISR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI8400AB-B-ISR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SI8400AB-B-ISR?
SI8400AB-B-ISR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SI8400AB-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 SI8400AB-B-ISR?
For technical support, including SI8400AB-B-ISR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI8400AB-B-ISR requirements.
6.How does Aetrix verify that SI8400AB-B-ISR is sourced from the original manufacturer or authorized distributors?
All SI8400AB-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 SI8400AB-B-ISR meets industry standards.
7.What is the process for return or replacement of SI8400AB-B-ISR?
All SI8400AB-B-ISR units undergo pre-shipment inspection (PSI). If there is an issue with SI8400AB-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 SI8400AB-B-ISR part is unused and in its original packaging.
Return procedure for SI8400AB-B-ISR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SI8400AB-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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