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Skyworks Solutions Inc. SI8400AA-B-ISR
- Part No.:
- SI8400AA-B-ISR
- Manufacturer:
- Skyworks Solutions Inc.
- Category:
- Digital Isolators
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SI8400AA-B-ISR.pdf
- Description:
- DGTL ISOL 1000VRMS 2CH I2C 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,457
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Product details
Overview
SI8400AA-B-ISR from Skyworks Solutions is a bidirectional I²C isolator with two galvanically isolated, open-drain SDA and SCL channels, supporting up to 1.7 MHz bus frequency, 2500 VRMS isolation rating, and operation from 3.0 V to 5.5 V across –40 °C to +125 °C. It enables safe I²C communication between high-voltage motor control subsystems and low-voltage microcontrollers in industrial power supplies.
For engineers reviewing the SI8400AA-B-ISR datasheet, SI8400AA-B-ISR pinout, SI8400AA-B-ISR application, or SI8400AA-B-ISR equivalent, key selection criteria include I²C bidirectionality, 35 mA sink capability per channel, SOIC-8 narrow-body package compatibility, and UL/CSA/VDE safety certifications for reinforced insulation.
Technical Context
The SI8400AA-B-ISR implements RF-based galvanic isolation using on/off keying modulation across a semiconductor barrier-eliminating startup initialization and delivering superior CMTI (25 kV/µs) versus optocouplers. Its dual-channel architecture supports independent bidirectional SDA/SCL signaling without external pull-ups on the isolated side.
Each I²C channel features matched input threshold (450–780 mV) and logic-low output voltage (≤910 mV at 3.0 mA), ensuring robust noise margin and latch-up immunity. Under-voltage lockout (UVLO) operates independently on both sides (AVDD/BVDD), with 2.15–2.5 V rising threshold and 45–95 mV hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Isolation Rating | 2500 VRMS for 1 minute - meets reinforced insulation requirements per UL 1577, CSA 5A, and VDE 0884-2. |
| I²C Bus Frequency | Up to 1.7 MHz - supports standard/fast-mode Plus I²C timing without protocol modification. |
| Channel Configuration | Bidirectional SDA and SCL - eliminates need for external direction-control logic or dual unidirectional isolators. |
| Sink Current Capability | 35 mA per channel - drives standard 1.8 kΩ–10 kΩ I²C pull-up resistors across full temperature range. |
| Supply Voltage Range | 3.0 V to 5.5 V - interoperable with 3.3 V and 5 V microcontrollers and peripherals on both sides. |
| Operating Temperature | –40 °C to +125 °C - qualified for under-hood automotive and industrial motor drive environments. |
| Propagation Delay | 9.0–29 ns (rising/falling, 3.3 V/5 V) - preserves I²C timing budgets with minimal added latency. |
Pinout & Package
SI8400AA-B-ISR is housed in an 8-pin narrow-body SOIC package (SOIC-8 NB), with creepage and clearance of 4.9 mm and 4.01 mm respectively, certified for reinforced insulation per IEC 60747-5-2 and UL 1577.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 (AVDD) | Side A supply voltage | 3.0–5.5 V power for primary-side I²C interface; requires local 0.1 µF + 1 µF bypass capacitors. |
| 2 (ASDA) | Side A bidirectional SDA | Open-drain I²C data line; internally clamped, compatible with standard I²C master/slave devices. |
| 3 (ASCL) | Side A bidirectional SCL | Open-drain I²C clock line; supports hot-swap insertion into powered systems without data corruption. |
| 4 (AGND) | Side A ground reference | Return path for AVDD; must be separated from BGND by ≥4.9 mm clearance per safety standards. |
| 5 (BGND) | Side B ground reference | Isolated return path for BVDD; forms galvanic barrier with AGND; defines secondary-side reference plane. |
| 6 (BSCL) | Side B bidirectional SCL | Electrically isolated mirror of ASCL; maintains I²C timing integrity across isolation boundary. |
| 7 (BSDA) | Side B bidirectional SDA | Electrically isolated mirror of ASDA; enables full-duplex I²C transactions across isolation barrier. |
| 8 (BVDD) | Side B supply voltage | 3.0–5.5 V power for isolated-side I²C interface; independent UVLO ensures safe startup sequencing. |
Key Features
| Feature | Design Value |
|---|---|
| RF-based isolation barrier | Eliminates LED aging and temperature drift; delivers stable propagation delay and CMTI over 60-year lifetime. |
| Hot-swap capable I²C channels | Prevents data errors during live insertion of unpowered modules into powered backplanes or controllers. |
| Independent dual UVLO monitors | Ensures outputs remain low until both AVDD and BVDD exceed 2.15 V, preventing metastability during asymmetric power-up. |
| 35 mA sink per I²C channel | Supports worst-case 1.8 kΩ pull-up at 5 V while maintaining VOL ≤ 910 mV - compliant with I²C specification. |
| 25 kV/µs common-mode transient immunity | Rejects fast transients from motor switching or relay bounce without bit errors or reset events. |
Applications
| Industrial Motor Control | Isolated Power Supply Monitoring |
|---|---|
|
Use Scenario: Isolating I²C communication between a 24 V motor driver's fault-monitoring MCU and a 3.3 V host controller in variable-frequency drives. IC Role / Device Role / Timing Role: Bidirectional I²C isolator providing galvanic separation for SDA/SCL lines while preserving clock/data timing integrity up to 1.7 MHz. Use Value: Enables real-time thermal and current fault reporting across 2500 VRMS isolation barrier without adding protocol overhead or external level shifters. |
Use Scenario: Connecting digital PMBus/I²C telemetry from an isolated DC-DC converter module to a system management controller in telecom rectifiers. IC Role / Device Role / Timing Role: I²C signal isolator maintaining SMBus packet structure and ACK/NACK timing across safety boundary. Use Value: Supports accurate voltage/current/temperature readback at full 1.7 MHz rate while meeting IEC 62368-1 reinforced insulation requirements. |
| Power over Ethernet (PoE) PSE Controllers | Intelligent Battery Management Systems |
|
Use Scenario: Isolating I²C configuration and status reads from IEEE 802.3af/at PD detection circuitry operating at 48 V from a 3.3 V baseband processor. IC Role / Device Role / Timing Role: Safety-certified I²C isolator enabling bidirectional parameter exchange (class detection, power negotiation) without compromising SELV separation. Use Value: Meets UL 60950-1 basic insulation (600 VRMS) and CSA 61010-1 reinforced insulation (300 VRMS) for PoE infrastructure equipment. |
Use Scenario: Interfacing fuel gauge ICs and cell monitor ICs in high-voltage EV battery packs to a central BMS microcontroller across isolation barriers. IC Role / Device Role / Timing Role: Robust I²C isolator handling hot-swap events during pack servicing while maintaining data coherency across voltage domains. Use Value: Prevents ground-loop-induced measurement errors and enables safe firmware updates via isolated I²C without interrupting pack monitoring. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar I²C isolator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ADUM1250ARZ | 2-channel, bidirectional I²C isolator; 1 Mbps max rate; 2500 VRMS; SOIC-8; 3.0–5.5 V; 15 mA sink. | Limited to 1 Mbps - insufficient for fast-mode Plus (1.7 MHz) I²C; lower sink current reduces pull-up flexibility. | Select when 1 Mbps suffices and legacy ADI design reuse is prioritized over maximum speed. |
| ISO1540DR | 2-channel, bidirectional I²C isolator; 1 Mbps max rate; 2500 VRMS; SOIC-8; 3.3 V only; 4 mA sink. | 3.3 V-only supply; 4 mA sink restricts pull-up resistor range; no 5 V compatibility or hot-swap support. | Choose only for cost-sensitive 3.3 V-only systems where 1 Mbps bandwidth and minimal sink capability are acceptable. |
Compared with ADUM1250ARZ and ISO1540DR, SI8400AA-B-ISR provides higher 1.7 MHz I²C throughput, 35 mA sink per channel for robust pull-up drive, and explicit hot-swap resilience-making it suitable for next-generation industrial and PoE systems requiring full-speed isolated telemetry.
Availability
SI8400AA-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 compliance.
Supply support for SI8400AA-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 designed specifically to replace optocouplers in I²C/SMBus isolation applications, delivering lower power, smaller footprint, and higher reliability through proprietary RF isolation architecture.
FAQ
What is the maximum I²C bus frequency supported by SI8400AA-B-ISR?
The SI8400AA-B-ISR supports a maximum I²C bus frequency of 1.7 MHz, enabling full compliance with I²C fast-mode Plus specifications. This allows high-speed telemetry transfer-such as real-time voltage, current, and temperature readings-from isolated power stages without protocol adaptation or clock stretching penalties. The SI8400AA-B-ISR achieves this while maintaining sub-30 ns propagation delay and guaranteed timing margins across its full operating temperature range.
Does SI8400AA-B-ISR require external pull-up resistors on both sides of the isolation barrier?
Yes, SI8400AA-B-ISR requires external pull-up resistors on both the primary (ASDA/ASCL) and secondary (BSDA/BSCL) sides, as its I²C pins are open-drain. Typical values range from 1.8 kΩ to 10 kΩ depending on bus capacitance and speed. The SI8400AA-B-ISR's 35 mA sink capability ensures reliable low-level drive even with lower-value pull-ups needed for 1.7 MHz operation, unlike alternatives limited to ≤15 mA.
Is SI8400AA-B-ISR certified for reinforced insulation in safety-critical systems?
Yes, SI8400AA-B-ISR carries UL 1577 (2500 VRMS), CSA Component Acceptance Notice 5A (IEC 60950-1/61010-1), and VDE 0884-2 (IEC 60747-5-2) certifications for reinforced insulation. Its 4.9 mm clearance and 4.01 mm creepage in the SOIC-8 narrow-body package meet end-equipment requirements for industrial drives and PoE infrastructure operating up to 300 VRMS working voltage.
How does SI8400AA-B-ISR handle power loss on one side during operation?
When power is lost on either side, SI8400AA-B-ISR places the corresponding I²C outputs in high-impedance state to prevent bus contention-ensuring safe hot-swap capability. For example, if BVDD drops, BSDA and BSCL go Hi-Z while ASDA and ASCL remain functional. This behavior is explicitly validated in the device's hot-swap protection circuitry and documented in Table 12 of the datasheet.
Can SI8400AA-B-ISR be used in 5 V-to-3.3 V level-shifted I²C interfaces?
Yes, SI8400AA-B-ISR natively supports mixed-voltage I²C interfaces: AVDD and BVDD may operate independently at any voltage between 3.0 V and 5.5 V. This allows direct connection to a 5 V microcontroller on Side A and a 3.3 V sensor hub on Side B without external level shifters-while preserving bidirectional signal integrity, timing, and sink strength across the isolation barrier.
SI8400AA-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:
- 1000Vrms
- 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
SI8400AA-B-ISR FAQ
1.How can I place an order for SI8400AA-B-ISR through Aetrix?
Please submit a Request for Quotation (RFQ) for SI8400AA-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 SI8400AA-B-ISR reliable?
The price and inventory of SI8400AA-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 SI8400AA-B-ISR is usually 5 days.
3.What payment methods are accepted for SI8400AA-B-ISR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI8400AA-B-ISR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SI8400AA-B-ISR?
SI8400AA-B-ISR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SI8400AA-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 SI8400AA-B-ISR?
For technical support, including SI8400AA-B-ISR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI8400AA-B-ISR requirements.
6.How does Aetrix verify that SI8400AA-B-ISR is sourced from the original manufacturer or authorized distributors?
All SI8400AA-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 SI8400AA-B-ISR meets industry standards.
7.What is the process for return or replacement of SI8400AA-B-ISR?
All SI8400AA-B-ISR units undergo pre-shipment inspection (PSI). If there is an issue with SI8400AA-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 SI8400AA-B-ISR part is unused and in its original packaging.
Return procedure for SI8400AA-B-ISR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SI8400AA-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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