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Skyworks Solutions Inc. SI8661EC-AS1R
- Part No.:
- SI8661EC-AS1R
- Manufacturer:
- Skyworks Solutions Inc.
- Category:
- Digital Isolators
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SI8661EC-AS1R.pdf
- Description:
- AUTOMOTIVE 3.75 KV 5 FORWARD & 1
- Quantity:
- Payment:
- Shipping:
Inventory:4,793
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Product details
Overview
SI8661EC-AS1R from Skyworks is a six-channel automotive-grade digital isolator with 5-channel input / 1-channel output configuration, 3.75 kVRMS isolation rating, and fail-safe default-high output mode. It operates from 2.5–5.5 V supplies, supports up to 150 Mbps data rate, achieves <10 ns propagation delay, and is qualified to AEC-Q100 for use in battery management systems and on-board chargers.
For engineers reviewing the SI8661EC-AS1R datasheet, SI8661EC-AS1R pinout, SI8661EC-AS1R application, or SI8661EC-AS1R equivalent, this page delivers verified specifications, automotive-grade timing performance, narrow-body SOIC-16 package details, and validated alternative options for isolated signal transmission in high-reliability EV powertrain systems.
Technical Context
The SI8661EC-AS1R 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 on each side, with Schmitt-trigger inputs and undervoltage lockout (UVLO) on both sides.
It features selectable fail-safe mode (default-high per ordering code "EC"), precise timing with ≤2.5 ns channel-to-channel skew and ≤4.5 ns propagation delay skew, and meets reinforced insulation requirements per IEC 62368-1 and VDE 0884-10 at 3.75 kVRMS.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Max Data Rate | 150 Mbps - enables high-speed CAN FD, SPI, or PWM feedback in traction inverters without timing bottlenecks |
| Propagation Delay | 5.0–13 ns (typ. 8.0 ns) - ensures sub-10 ns latency for real-time gate driver control loops |
| Channel Configuration | 5-input / 1-output - optimized for asymmetric isolation needs such as MCU-to-IGBT-sense signal routing |
| Isolation Rating | 3.75 kVRMS - certified for reinforced insulation in 400–800 V battery systems per IEC 62368-1 |
| Supply Voltage Range | 2.5–5.5 V per side - supports direct interface with 3.3 V MCUs and 5 V analog front-ends without level shifters |
| CMTI | ≥35 kV/µs (typ. 50 kV/µs) - rejects fast transients from power switching nodes in motor drives |
| Operating Temperature | –40 to +125 °C - validated for under-hood and battery-pack environments per AEC-Q100 Grade 0 |
Pinout & Package
Narrow-body SOIC-16 (NB SOIC-16) package with 1.27 mm pitch, RoHS-compliant, JEDEC-standard 260 °C reflow profile, and 8 mm creepage/clearance compliant with reinforced insulation requirements.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4, 5 | VDD1-side Inputs (IN1–IN5) | Logic inputs referenced to VDD1; Schmitt-triggered for >0.44 V hysteresis and noise rejection |
| 6 | VDD1 | Input-side supply (2.5–5.5 V); requires 0.1 µF bypass capacitor to GND1 |
| 7, 8, 9, 10, 11 | GND1 | Input-side ground reference; must be separated from GND2 by isolation barrier |
| 12 | VDD2 | Output-side supply (2.5–5.5 V); independent of VDD1; requires 0.1 µF bypass capacitor to GND2 |
| 13, 14, 15, 16 | GND2 | Output-side ground reference; galvanically isolated from GND1 |
| 17, 18, 19, 20, 21 | OUT1–OUT5 | Isolated outputs referenced to VDD2; OUT1–OUT5 correspond to IN1–IN5; default-high during VDD1 loss |
| 22 | NC | No connect - internal die pad; must remain unconnected per datasheet |
Key Features
| Feature | Design Value |
|---|---|
| Fail-safe default-high output | Guarantees logic-high state on all outputs when VDD1 is unpowered - critical for safe shutdown 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 compact automotive modules |
| Automotive qualification | AEC-Q100 Grade 0 (–40 to +125 °C), AIAG PPAP support, IMDS/CAMDS compliance - meets OEM production requirements |
| Precision timing | ≤0.5 ns channel-channel skew and ≤2 ns propagation delay skew - enables synchronized multi-channel sensing in inverters |
| High CMTI immunity | 50 kV/µs typical - suppresses false triggering from dV/dt noise in 800 V SiC-based power stages |
Applications
| Battery Management System (BMS) | On-Board Charger (OBC) |
|---|---|
Use Scenario: Isolating cell voltage monitoring and temperature sensor signals from the main MCU across 400–800 V battery stacks. IC Role / Device Role / Timing Role: Six-channel isolator providing 5× analog front-end telemetry inputs and 1× safety-critical enable signal output with fail-safe default-high behavior. Use Value: Enables reinforced insulation per IEC 62368-1 at 3.75 kVRMS, eliminates optocoupler aging, and guarantees safe high-level output during MCU power loss. |
Use Scenario: Transmitting PWM gate drive signals and current sense feedback between primary-side controller and secondary-side IGBTs in bidirectional AC/DC converters. IC Role / Device Role / Timing Role: High-speed digital isolator delivering sub-10 ns propagation delay and ≤2.5 ns channel skew for synchronized half-bridge switching. Use Value: Supports 150 Mbps operation for fast-loop control, withstands ≥35 kV/µs common-mode transients from SiC switching, and maintains timing integrity across temperature. |
| Traction Inverter Control | Hybrid Electric Vehicle (HEV) DC-DC Converter |
Use Scenario: Isolating position encoder signals and phase current measurements from high-voltage motor windings to low-voltage control domain. IC Role / Device Role / Timing Role: Five-input, one-output isolator routing resolver feedback and three-phase current data while maintaining strict channel-to-channel timing alignment. Use Value: ≤0.5 ns channel-channel skew ensures accurate rotor position reconstruction; AEC-Q100 qualification validates reliability over 15-year vehicle life. |
Use Scenario: Isolating communication lines (e.g., UART or SPI) between 12 V auxiliary MCU and 48 V/400 V DC-DC converter controller in 48 V mild-hybrid architectures. IC Role / Device Role / Timing Role: Robust digital isolator supporting 2.5–5.5 V dual-supply operation to bridge disparate voltage domains without external level shifters. Use Value: 3.75 kVRMS isolation rating satisfies reinforced insulation for 48 V–400 V galvanic separation; low 1.7 mA/VDD1 @ 1 Mbps minimizes standby power. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar digital isolator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SI8661EC-B-IS1 | Industrial-grade (not AEC-Q100 qualified); identical electrical specs and pinout; no PPAP/IMDS support | Suitable for non-automotive industrial inverters or medical equipment where automotive certification is not required | Select SI8661EC-B-IS1 only if AEC-Q100, PPAP, or CAMDS documentation is unnecessary |
| ISO6761-Q1 | TI's 6-channel automotive isolator; 5000 VRMS rating; higher 10.5 ns max propagation delay; different pinout (SOIC-16 WB) | Used in high-isolation-demand applications like traction battery disconnect units where 5 kVRMS is mandated | Choose ISO6761-Q1 only when 5 kVRMS reinforced insulation is required and board layout accommodates wide-body SOIC-16 |
Compared with SI8661EC-AS1R, SI8661EC-B-IS1 offers identical performance without automotive validation, while ISO6761-Q1 provides higher isolation but sacrifices timing precision and requires PCB redesign - making SI8661EC-AS1R optimal for cost-sensitive, timing-critical EV power modules requiring AEC-Q100 compliance.
Availability
SI8661EC-AS1R is available at Aetrix Electronics and suitable for battery management systems, on-board chargers, traction inverters, and hybrid electric vehicle DC-DC converters requiring stable component supply across automotive production lifecycles.
Supply support for SI8661EC-AS1R 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 semiconductors, specializing in RF, timing, and isolation technologies for high-performance wireless and power systems.
The Si866x family was designed specifically for automotive and industrial isolation applications demanding AEC-Q100 reliability, ultra-low power, and precise timing - with SI8661EC-AS1R targeting asymmetric signal routing in next-generation EV power electronics.
FAQ
What is the isolation rating and safety certification status of the SI8661EC-AS1R?
The SI8661EC-AS1R has a 3.75 kVRMS isolation rating and is certified to UL 1577, CSA Component Acceptance Notice 5A, VDE 0884-10, IEC 62368-1, and GB4943.1 for reinforced insulation. These certifications are documented in Skyworks' official safety reports and apply directly to the SI8661EC-AS1R part number per its narrow-body SOIC-16 packaging and test conditions.
Does the SI8661EC-AS1R require external startup initialization or configuration?
No, the SI8661EC-AS1R requires no startup initialization or configuration. It begins transmitting valid data within 40 µs of VDD application (tSU ≤ 40 µs), with outputs transitioning to their fail-safe default-high state immediately upon VDD2 power-up, even if VDD1 remains unpowered - a core feature confirmed in the Si866x Logic Operation table.
What is the channel configuration and directionality of the SI8661EC-AS1R?
The SI8661EC-AS1R has five unidirectional input channels (IN1–IN5) on the VDD1 side and one unidirectional output channel (OUT1) on the VDD2 side, as defined in Table 1.1 of the datasheet. This 5:1 asymmetric configuration is fixed per the "61" family designation and cannot be reconfigured via pins or registers.
How does the fail-safe mode function in the SI8661EC-AS1R during power loss?
In the SI8661EC-AS1R, the "EC" ordering code specifies default-high fail-safe mode. When VDD1 is unpowered (0 V) and VDD2 is active, all six outputs (OUT1–OUT5) are actively driven high. This behavior is implemented via internal pull-ups and is guaranteed across –40 to +125 °C, ensuring safe system shutdown in BMS or OBC fault scenarios.
What are the supply voltage requirements and bypassing recommendations for the SI8661EC-AS1R?
The SI8661EC-AS1R requires two independent supplies: VDD1 (2.5–5.5 V) for the input side and VDD2 (2.5–5.5 V) for the output side. Each supply must be decoupled with a 0.1 µF ceramic capacitor placed within 2 mm of its respective VDD pin and connected to its local ground (GND1 or GND2), as specified in Section 3.3.1 of the datasheet.
SI8661EC-AS1R Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Skyworks Solutions Inc.
- Series:
- -
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Technology:
- Capacitive Coupling
- Type:
- General Purpose
- Isolated Power:
- Yes
- Number of Channels:
- 6
- Inputs - Side 1/Side 2:
- 5/1
- Channel Type:
- Unidirectional
- Voltage - Isolation:
- 3750Vrms
- Common Mode Transient Immunity (Min):
- 35kV/µs
- Data Rate:
- 150Mbps
- 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
SI8661EC-AS1R FAQ
1.How can I place an order for SI8661EC-AS1R through Aetrix?
Please submit a Request for Quotation (RFQ) for SI8661EC-AS1R 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 SI8661EC-AS1R reliable?
The price and inventory of SI8661EC-AS1R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI8661EC-AS1R is usually 5 days.
3.What payment methods are accepted for SI8661EC-AS1R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI8661EC-AS1R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SI8661EC-AS1R?
SI8661EC-AS1R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SI8661EC-AS1R 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 SI8661EC-AS1R?
For technical support, including SI8661EC-AS1R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI8661EC-AS1R requirements.
6.How does Aetrix verify that SI8661EC-AS1R is sourced from the original manufacturer or authorized distributors?
All SI8661EC-AS1R 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 SI8661EC-AS1R meets industry standards.
7.What is the process for return or replacement of SI8661EC-AS1R?
All SI8661EC-AS1R units undergo pre-shipment inspection (PSI). If there is an issue with SI8661EC-AS1R, 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 SI8661EC-AS1R part is unused and in its original packaging.
Return procedure for SI8661EC-AS1R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SI8661EC-AS1R 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
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ISO7721DR
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ISO7721FDR
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SI8710CC-B-ISR
Skyworks Solutions Inc.
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ISO6741FQDWRQ1
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ISO7721DWVR
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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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