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Skyworks Solutions Inc. SI8661AB-AS1
- Part No.:
- SI8661AB-AS1
- Manufacturer:
- Skyworks Solutions Inc.
- Category:
- Digital Isolators
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SI8661AB-AS1.pdf
- Description:
- AUTOMOTIVE 2.5 KV 5 FORWARD & 1
- Quantity:
- Payment:
- Shipping:
Inventory:4,267
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Product details
Overview
SI8661AB-AS1 from Skyworks is a six-channel automotive-grade digital isolator with 5-channel input / 1-channel output configuration, 2.5 kVRMS isolation rating, and SOIC-16 narrow-body package. It supports DC–150 Mbps data rates, achieves <10 ns propagation delay, and operates across –40°C to +125°C for use in battery management systems and traction inverters.
For engineers reviewing the SI8661AB-AS1 datasheet, SI8661AB-AS1 pinout, SI8661AB-AS1 application, or SI8661AB-AS1 equivalent, this page delivers verified specifications, fail-safe mode behavior, CMTI performance (50 kV/µs), automotive AEC-Q100 qualification, and precise channel skew (0.5 ns) - all critical for high-reliability isolated signal transmission in EV powertrain designs.
Technical Context
The SI8661AB-AS1 implements RF-based on/off keying across a semiconductor isolation barrier, eliminating startup initialization and enabling robust noise immunity without optical components. Its dual-supply architecture (VDD1/VDD2) supports independent 2.5–5.5 V operation per side, with Schmitt-trigger inputs and selectable fail-safe default output (low, per ordering code "B").
Each of its six channels features matched timing: 8 ns typical propagation delay, ≤0.5 ns channel-to-channel skew, and ≤2 ns propagation delay skew. Undervoltage lockout (UVLO) operates independently on both sides with 70 mV hysteresis, ensuring deterministic behavior during power sequencing in automotive subsystems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Channels & Direction | 6-channel, 5-input / 1-output split - enables asymmetric signal routing (e.g., 5 control signals + 1 feedback path) across isolation barrier |
| Isolation Rating | 2.5 kVRMS - certified to UL 1577, VDE 0884-10, CSA 5A, and IEC 62368-1 for reinforced insulation in industrial and automotive end equipment |
| Max Data Rate | 150 Mbps - supports high-speed serial interfaces including SPI, RS-485 transceiver control, and gate driver status reporting |
| Propagation Delay | 5–13 ns (min–max), 8 ns typical - ensures sub-10 ns timing predictability for real-time motor control loop closure |
| CMTI | 50 kV/µs (typical) - rejects fast common-mode transients induced by SiC/GaN switching in inverters and onboard chargers |
| Supply Voltage | 2.5–5.5 V per side - allows direct interfacing with 3.3 V microcontrollers and 5 V analog front-ends without level-shifting |
| Fail-Safe Default | Low output state on VDD1 loss - prevents unintended activation of downstream drivers or safety-critical actuators during input-side power fault |
Pinout & Package
SI8661AB-AS1 uses a RoHS-compliant 16-pin narrow-body SOIC package (5.3 mm width, 10.3 mm length) with 8.3 mm creepage and 8.0 mm clearance - compliant with IEC 60664-1 for reinforced insulation at 2.5 kVRMS.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4, 5 | VDD1 Power Supply | Input-side supply pins - must be decoupled with 0.1 µF capacitor each; shared rail for 5 input channels |
| 6, 7, 8, 9, 10 | IN1–IN5 Inputs | Digital input terminals referenced to VDD1/GND1 - Schmitt-triggered for >0.44 V hysteresis and noise rejection |
| 11 | GND1 | Input-side ground reference - must be separated from GND2 by ≥8 mm PCB creepage |
| 12, 13, 14, 15, 16 | OUT1–OUT5 Outputs | Isolated output terminals referenced to VDD2/GND2 - 50 Ω nominal output impedance for controlled-impedance trace routing |
| 16 | OUT6 | Single isolated output channel - matches IN5 function but resides on output side; enables 5:1 asymmetric isolation |
| - | VDD2 / GND2 | No dedicated VDD2/GND2 pins - VDD2 supplied via pins 12–16 (output drivers), GND2 via pin 11 only (shared ground plane not permitted) |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 Grade 0 qualification | Validated for operation from –40°C to +125°C ambient, with zero-defect manufacturing flow and AIAG-compliant PPAP documentation |
| Selectably fail-safe low default | Guarantees OUT1–OUT6 drive low when VDD1 is unpowered - eliminates risk of floating control lines in BMS fault conditions |
| Ultra-low power at 100 Mbps | 8.8 mA (VDD1) + 23 mA (VDD2) typical at 5 V - reduces thermal load in densely packed traction inverter gate driver boards |
| 0.5 ns channel-to-channel skew | Enables simultaneous sampling of multi-phase current/voltage feedback without inter-channel timing error compensation |
| RF-based isolation architecture | Eliminates LED aging, temperature drift, and startup delay - delivers stable timing over 60-year lifetime at rated voltage |
Applications
| Battery Management System (BMS) | Traction Inverter Control |
|---|---|
|
Use Scenario: Isolating cell voltage monitoring ADC outputs and pack contactor control signals between high-voltage battery stack and low-voltage MCU. IC Role / Device Role / Timing Role: SI8661AB-AS1 transmits 5 analog front-end digitized values and 1 safety shutdown command across 2.5 kV barrier with <10 ns delay. Use Value: Enables real-time cell balancing decisions and failsafe disconnection within 1 µs of fault detection - meeting ASIL-C timing requirements. |
Use Scenario: Transmitting PWM gate drive enable/disable and fault feedback from isolated gate driver ICs to main inverter MCU. IC Role / Device Role / Timing Role: SI8661AB-AS1 carries 5 independent gate enable signals and 1 desaturation fault flag across isolation barrier. Use Value: 0.5 ns channel skew preserves phase alignment across 3-phase legs; 50 kV/µs CMTI prevents false triggering during 100+ V/ns SiC switching events. |
| On-Board Charger (OBC) | DC Fast Charging Station |
|
Use Scenario: Isolating digital control signals between AC/DC PFC controller and DC/DC LLC controller in bidirectional OBC topologies. IC Role / Device Role / Timing Role: SI8661AB-AS1 routes 5 PFC status/control bits and 1 LLC fault indicator across galvanic barrier. Use Value: Sub-10 ns propagation delay maintains tight synchronization between PFC and LLC stages - improving efficiency and reducing EMI. |
Use Scenario: Interfacing isolated current/voltage sensors and IGBT/SiC gate drivers in liquid-cooled 150 kW+ charging modules. IC Role / Device Role / Timing Role: SI8661AB-AS1 conveys 5 sensor readings and 1 overtemperature lockout signal to system controller. Use Value: Automotive-grade construction ensures reliability under continuous 40–85°C ambient and 100% duty-cycle operation in outdoor charging infrastructure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar digital isolator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ADUM6601ARWZ | 6-channel, 3.75 kVRMS, SOIC-16 wide-body; higher isolation but no AEC-Q100 qualification; 12 ns max propagation delay | Industrial UPS and solar inverters where automotive qualification is unnecessary and higher working voltage is required | Choose ADUM6601ARWZ when 3.75 kVRMS reinforced insulation is mandated and AEC-Q100 is not required. |
| ISO6761QDWR | 6-channel, 5 kVRMS, SOIC-16 wide-body; AEC-Q100 qualified; 11 ns max propagation delay; 10 Mbps max data rate | Automotive body electronics and infotainment where lower speed suffices and highest isolation is needed | Choose ISO6761QDWR when 5 kVRMS is mandatory and data rate ≤10 Mbps meets system requirements. |
Compared with ADUM6601ARWZ and ISO6761QDWR, SI8661AB-AS1 uniquely balances 150 Mbps speed, AEC-Q100 Grade 0 qualification, 2.5 kVRMS isolation, and 0.5 ns channel skew - making it optimal for time-critical EV powertrain control where both speed and automotive reliability are non-negotiable.
Availability
SI8661AB-AS1 is available at Aetrix Electronics and suitable for battery management systems, traction inverters, on-board chargers, and DC fast charging stations requiring stable component supply across automotive production lifecycles.
Supply support for SI8661AB-AS1 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 Si866x family was designed specifically for high-reliability automotive and industrial isolation - delivering ultra-low power, precise timing, and AEC-Q100-qualified robustness in compact SOIC packages.
FAQ
What is the default output state of SI8661AB-AS1 during input-side power loss?
The SI8661AB-AS1 has a selectable fail-safe mode defined by its ordering code: the "B" suffix indicates a default-low output state. When VDD1 is unpowered and VDD2 remains active, all six outputs (OUT1–OUT6) drive logic low - preventing unintended activation of downstream circuits in safety-critical automotive applications such as battery disconnect control.
Does SI8661AB-AS1 require external startup initialization or configuration?
No. SI8661AB-AS1 is a CMOS digital isolator with no startup initialization requirement. It begins transmitting valid data within 40 µs of VDD1/VDD2 reaching UVLO threshold (2.24 V), and operates immediately upon power-up - unlike optocouplers or programmable isolators that need firmware handshaking or register writes.
What is the maximum operating temperature for SI8661AB-AS1, and how is it validated?
SI8661AB-AS1 is rated for –40°C to +125°C ambient operation and qualified to AEC-Q100 Grade 0. This is validated through accelerated life testing, HTOL (High-Temperature Operating Life), and thermal cycling across the full range - with zero-defect methodology applied throughout automotive-specific manufacturing flows.
How does SI8661AB-AS1 achieve 50 kV/µs common-mode transient immunity?
SI8661AB-AS1 achieves 50 kV/µs CMTI via its RF-based modulation architecture and optimized internal layout. Unlike capacitive or magnetic isolators, its semiconductor isolation barrier rejects fast dV/dt transients without coupling into signal paths - confirmed per VDE 0884-10 test conditions with 1500 V common-mode step and 5 ns rise time.
Can SI8661AB-AS1 be used with 2.5 V and 5 V supplies simultaneously on opposite sides?
Yes. SI8661AB-AS1 supports independent 2.5–5.5 V operation on VDD1 and VDD2. For example, VDD1 can be 3.3 V (microcontroller I/O domain) while VDD2 is 5 V (gate driver logic domain), with full timing and noise immunity specifications maintained - no level shifters required.
SI8661AB-AS1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Skyworks Solutions Inc.
- Series:
- -
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Technology:
- Capacitive Coupling
- Type:
- General Purpose
- Isolated Power:
- Yes
- Number of Channels:
- 6
- Inputs - Side 1/Side 2:
- -
- Channel Type:
- Unidirectional
- Voltage - Isolation:
- -
- Common Mode Transient Immunity (Min):
- 35kV/µs
- Data Rate:
- -
- Propagation Delay tpLH / tpHL (Max):
- 13ns, 13ns
- Pulse Width Distortion (Max):
- 4.5ns
- Rise / Fall Time (Typ):
- 2.5ns, 2.5ns
- Voltage - Supply:
- 2.375V ~ 5.5V
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Operating Temperature:
- -40°C ~ 125°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
SI8661AB-AS1 FAQ
1.How can I place an order for SI8661AB-AS1 through Aetrix?
Please submit a Request for Quotation (RFQ) for SI8661AB-AS1 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 SI8661AB-AS1 reliable?
The price and inventory of SI8661AB-AS1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI8661AB-AS1 is usually 5 days.
3.What payment methods are accepted for SI8661AB-AS1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI8661AB-AS1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SI8661AB-AS1?
SI8661AB-AS1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SI8661AB-AS1 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 SI8661AB-AS1?
For technical support, including SI8661AB-AS1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI8661AB-AS1 requirements.
6.How does Aetrix verify that SI8661AB-AS1 is sourced from the original manufacturer or authorized distributors?
All SI8661AB-AS1 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 SI8661AB-AS1 meets industry standards.
7.What is the process for return or replacement of SI8661AB-AS1?
All SI8661AB-AS1 units undergo pre-shipment inspection (PSI). If there is an issue with SI8661AB-AS1, 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 SI8661AB-AS1 part is unused and in its original packaging.
Return procedure for SI8661AB-AS1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SI8661AB-AS1 Tags
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ISO1212DBQR
Texas Instruments
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ISO6721BDR
Texas Instruments
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SI8710AC-B-ISR
Skyworks Solutions Inc.
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ISO7720FDR
Texas Instruments
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ISO7721DR
Texas Instruments
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ISO7721FDR
Texas Instruments
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SI8710CC-B-ISR
Skyworks Solutions Inc.
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ISO6741FQDWRQ1
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ISO7721DWVR
Texas Instruments
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ISO7762FDBQR
Texas Instruments
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ISO7741DWR
Texas Instruments
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ISO7741FDWR
Texas Instruments
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