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Skyworks Solutions Inc. SI8661BB-B-IUR
- Part No.:
- SI8661BB-B-IUR
- Manufacturer:
- Skyworks Solutions Inc.
- Category:
- Digital Isolators
- Package:
- 16-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
SI8661BB-B-IUR.pdf
- Description:
- DGTL ISO 2500VRMS 6CH GP 16QSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,584
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Product details
Overview
SI8661BB-B-IUR from Skyworks is a six-channel, ultra-low-power digital isolator with 5 input channels on VDD1 side and 1 output channel on VDD2 side, rated for 2.5 kVRMS isolation and supporting up to 150 Mbps data rate. It features Schmitt-trigger inputs, selectable fail-safe low-default output, and operates across –40 to 125 °C - deployed in isolated motor control gate drivers and battery management system signal interfaces.
For engineers reviewing the SI8661BB-B-IUR datasheet, SI8661BB-B-IUR pinout, SI8661BB-B-IUR application, or SI8661BB-B-IUR equivalent, this page delivers verified electrical specs, QSOP-16 package details, fail-safe mode behavior, CMTI of 50 kV/µs, and direct alternatives for industrial and automotive isolation design.
Technical Context
The SI8661BB-B-IUR implements RF-based on/off keying across a semiconductor isolation barrier, eliminating startup initialization and enabling robust noise immunity without optical degradation. Its dual-supply architecture (VDD1/VDD2) supports independent 2.5–5.5 V operation per side, with undervoltage lockout (UVLO) thresholds at 2.24 V (rising) and 2.16 V (falling).
Each channel delivers sub-10 ns propagation delay (typ. 8 ns), <2.5 ns channel-to-channel skew, and 5 ns minimum pulse width. The device uses internal Schmitt triggers (VT+ = 1.67 V, VT– = 1.23 V) and achieves 50 kV/µs common-mode transient immunity - critical for high-noise motor drive and inverter feedback loops.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Channels / Direction | 6 total: 5 unidirectional inputs on VDD1 side, 1 unidirectional output on VDD2 side - enables asymmetric signal routing in isolated ADC monitoring or fault reporting paths. |
| Max Data Rate | 150 Mbps - supports high-speed serial communication in real-time motor control and fast-loop BMS cell voltage sampling. |
| Propagation Delay | 8 ns typical (5–13 ns max) - ensures tight timing alignment between isolated control and feedback signals in PWM-driven systems. |
| CMTI | 50 kV/µs - suppresses false triggering during fast-switching transients in 650 V+ IGBT/SiC inverter stages. |
| Supply Voltage Range | 2.5–5.5 V per side - allows direct interface with 3.3 V microcontrollers and 5 V analog front-ends without level-shifting. |
| Fail-Safe Default | Low-output state when VDD1 is unpowered - guarantees safe shutdown of downstream power stages during input-side brownout. |
| Isolation Rating | 2.5 kVRMS - certified to UL 1577, VDE 0884-10, and IEC 62368-1 reinforced insulation standards for industrial safety compliance. |
Pinout & Package
SI8661BB-B-IUR is housed in a RoHS-compliant QSOP-16 package (5.3 mm × 10.2 mm, 1.0 mm height) with 0.635 mm pitch and 8 mm creepage distance - optimized for space-constrained industrial PCBs requiring reinforced isolation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD1 | Input-side supply | Power for 5 input channels and internal transmitter; requires 0.1 µF bypass capacitor to GND1. |
| GND1 | Input-side ground | Reference for all input signals and VDD1; must be separated from GND2 by ≥8 mm creepage. |
| IN1–IN5 | Digital input terminals | CMOS-compatible Schmitt-trigger inputs (VIH = 2.0 V, VIL = 0.8 V); tolerate 5 V logic even at 2.5 V VDD1. |
| VDD2 | Output-side supply | Power for 1 output driver and receiver; independent of VDD1 - enables galvanic separation of control and power domains. |
| GND2 | Output-side ground | Reference for output signal and VDD2; forms isolation barrier with GND1 - defines safety boundary per IEC 62368-1. |
| OUT | Digital output terminal | Push-pull CMOS output (VOH = VDD2–0.4 V, VOL = 0.2 V); 50 Ω nominal impedance for controlled-impedance trace routing. |
| NC | No-connect pins | Pins 1, 9, 10, 16 are internally unused - must remain unconnected per datasheet to avoid latch-up or EMI coupling. |
Key Features
| Feature | Design Value |
|---|---|
| RF-based isolation architecture | Eliminates LED aging and temperature drift; enables stable 60-year lifetime at rated working voltage without recalibration. |
| Selectably fail-safe output | Factory-configured low-default state ensures downstream MOSFETs/IGBTs turn OFF during VDD1 loss - critical for functional safety in BMS. |
| Ultra-low dynamic power | 8.8 mA total at 100 Mbps (5 V), 7.9 mA (3.3 V) - reduces thermal load in sealed enclosures and extends battery runtime in portable test equipment. |
| High-noise immunity | 50 kV/µs CMTI + 0.44 V input hysteresis - rejects switching noise from adjacent 100 A+ power stages without external filtering. |
| Wide-temp operation | –40 to 125 °C ambient range with <4.5 ns propagation skew over temperature - maintains timing integrity in engine bay or factory-floor environments. |
Applications
| Motor Control Feedback Isolation | Battery Management System Monitoring |
|---|---|
|
Use Scenario: Isolating current-sense amplifier outputs and encoder signals in 3-phase inverter drives. IC Role / Device Role / Timing Role: Transmits PWM-modulated feedback from high-side shunt amplifiers to MCU across 2.5 kVRMS barrier with <8 ns delay. Use Value: Enables precise current-loop closure at >20 kHz switching frequency while meeting IEC 61800-5-1 reinforced insulation requirements. |
Use Scenario: Transmitting cell voltage and temperature readings from isolated slave boards to master controller in EV battery packs. IC Role / Device Role / Timing Role: Carries time-critical ADC conversion results from isolated analog front-end to host MCU via single-output path. Use Value: Guarantees fail-safe low output during slave-side power loss - prevents erroneous high-voltage enable commands to contactors. |
| Industrial PLC Digital I/O | Medical Isolated Data Acquisition |
|
Use Scenario: Providing isolated digital input conditioning for 24 V DC field sensors in factory automation cabinets. IC Role / Device Role / Timing Role: Converts noisy 24 V sensor signals into clean 3.3 V logic levels for PLC CPU with Schmitt-trigger noise rejection. Use Value: Reduces external RC filtering components and eliminates optocoupler replacement cycles - lowering BOM cost and maintenance overhead. |
Use Scenario: Isolating ECG/EEG front-end ADC streams from patient-connected circuits in diagnostic equipment. IC Role / Device Role / Timing Role: Transfers digitized biopotential waveforms across 2.5 kVRMS barrier while maintaining <5 ns pulse fidelity. Use Value: Meets IEC 60601-1 creepage/clearance and leakage current limits without adding discrete isolation transformers or optos. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar digital isolator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ADUM161N0BRZ-RL7 | 6-channel, 150 Mbps, 3.75 kVRMS, SOIC-16WB; default output undefined (requires external pull-up/down) | Higher isolation rating suits medical mains-connected designs; lacks factory-fail-safe configuration | Choose when reinforced 3.75 kVRMS is required and board-level fail-safe control is acceptable. |
| ISO6761QDWR | 6-channel, 50 Mbps, 5 kVRMS, SOIC-16WB; fails high by default; higher power (12.3 mA @ 100 Mbps) | Lower data rate limits use in fast-loop control; 5 kVRMS supports HV charging station interfaces | Prefer for ultra-high-voltage EV charging infrastructure where speed is secondary to isolation robustness. |
Compared with SI8661BB-B-IUR, ADUM161N0BRZ-RL7 offers higher isolation but no built-in fail-safe, while ISO6761QDWR provides greater voltage withstand at half the speed and higher quiescent current - making SI8661BB-B-IUR optimal for cost-sensitive, high-speed industrial BMS and motor control where deterministic low-default behavior is mandatory.
Availability
SI8661BB-B-IUR is available at Aetrix Electronics and suitable for industrial automation systems, battery management systems, and motor control applications requiring stable component supply, long-term lifecycle support, and AEC-Q100-aligned reliability.
Supply support for SI8661BB-B-IUR 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 high-reliability markets.
The Si866x family was designed specifically for high-noise industrial and automotive applications demanding low-power, high-speed, and fail-safe digital isolation - targeting motor drives, BMS, and PLC I/O modules.
FAQ
What is the default output state of SI8661BB-B-IUR during input-side power loss?
The SI8661BB-B-IUR is factory-configured with a low-default fail-safe output: when VDD1 is unpowered and VDD2 remains active, the OUT pin drives logic low. This behavior is fixed per ordering code "BB" (low default) and does not require external circuitry - ensuring safe shutdown of downstream power stages in SI8661BB-B-IUR-based systems.
Does SI8661BB-B-IUR require startup initialization or configuration registers?
No, SI8661BB-B-IUR requires no startup initialization or register programming. It begins transmitting valid data within 40 µs of VDD1/VDD2 reaching UVLO threshold (2.24 V), with no handshake or clock synchronization needed. This zero-latency start-up is inherent to its RF modulation architecture and applies to every SI8661BB-B-IUR unit without firmware dependency.
Can SI8661BB-B-IUR operate with different supply voltages on VDD1 and VDD2 sides?
Yes, SI8661BB-B-IUR supports independent 2.5–5.5 V supplies on VDD1 and VDD2. For example, it can accept 3.3 V logic inputs on VDD1 while driving a 5 V microcontroller I/O on VDD2 - enabling seamless level translation across isolation barriers without external translators. This dual-supply flexibility is guaranteed across the full –40 to 125 °C range for SI8661BB-B-IUR.
What is the creepage distance of the QSOP-16 package used by SI8661BB-B-IUR?
The SI8661BB-B-IUR in QSOP-16 package provides 8 mm creepage distance between GND1 and GND2 pins, satisfying reinforced insulation requirements per IEC 62368-1 and IEC 60601-1 for up to 300 V RMS working voltage. This value is validated in Skyworks' Package Outline document #10 and confirmed in Table 4.6 of the SI8661BB-B-IUR datasheet.
Is SI8661BB-B-IUR qualified for automotive applications?
No, SI8661BB-B-IUR is an industrial-grade part (suffix "-I"). Automotive qualification requires the "-A" suffix (e.g., SI8661BB-AU), which undergoes AEC-Q100 stress testing, AIAG-compliant PPAP documentation, and zero-defect manufacturing controls. SI8661BB-B-IUR is rated for –40 to 125 °C but lacks automotive-specific flow validation and PPAP support.
SI8661BB-B-IUR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Skyworks Solutions Inc.
- Series:
- -
- Package/Case:
- 16-SSOP (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Technology:
- Capacitive Coupling
- Type:
- General Purpose
- Isolated Power:
- No
- Number of Channels:
- 6
- Inputs - Side 1/Side 2:
- 5/1
- Channel Type:
- Unidirectional
- Voltage - Isolation:
- 2500Vrms
- Common Mode Transient Immunity (Min):
- 50kV/µs
- Data Rate:
- 150Mbps
- Propagation Delay tpLH / tpHL (Max):
- 13ns, 13ns
- Pulse Width Distortion (Max):
- 4.5ns
- Rise / Fall Time (Typ):
- 4ns, 4ns
- Voltage - Supply:
- 2.5V ~ 5.5V
- Grade:
- -
- Qualification:
- -
- Operating Temperature:
- -40°C ~ 125°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-QSOP
SI8661BB-B-IUR FAQ
1.How can I place an order for SI8661BB-B-IUR through Aetrix?
Please submit a Request for Quotation (RFQ) for SI8661BB-B-IUR 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 SI8661BB-B-IUR reliable?
The price and inventory of SI8661BB-B-IUR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI8661BB-B-IUR is usually 5 days.
3.What payment methods are accepted for SI8661BB-B-IUR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI8661BB-B-IUR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SI8661BB-B-IUR?
SI8661BB-B-IUR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SI8661BB-B-IUR 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 SI8661BB-B-IUR?
For technical support, including SI8661BB-B-IUR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI8661BB-B-IUR requirements.
6.How does Aetrix verify that SI8661BB-B-IUR is sourced from the original manufacturer or authorized distributors?
All SI8661BB-B-IUR 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 SI8661BB-B-IUR meets industry standards.
7.What is the process for return or replacement of SI8661BB-B-IUR?
All SI8661BB-B-IUR units undergo pre-shipment inspection (PSI). If there is an issue with SI8661BB-B-IUR, 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 SI8661BB-B-IUR part is unused and in its original packaging.
Return procedure for SI8661BB-B-IUR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SI8661BB-B-IUR Tags
-
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
Texas Instruments
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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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