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Skyworks Solutions Inc. SI8645BC-AS1
- Part No.:
- SI8645BC-AS1
- Manufacturer:
- Skyworks Solutions Inc.
- Category:
- Digital Isolators
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SI8645BC-AS1.pdf
- Description:
- AUTOMOTIVE 3.75 KV 4-CHANNEL DIG
- Quantity:
- Payment:
- Shipping:
Inventory:2,449
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Product details
Overview
SI8645BC-AS1 from Skyworks is a quad-channel, unidirectional digital isolator with 4-input/0-output channel configuration, 3.75 kVRMS isolation rating, and narrow-body SOIC-16 package. It supports DC–150 Mbps data rates, achieves <10 ns propagation delay, and operates across –40 to +125 °C for industrial motor control and isolated power supply feedback loops.
For engineers reviewing the SI8645BC-AS1 datasheet, SI8645BC-AS1 pinout, SI8645BC-AS1 application, or SI8645BC-AS1 equivalent, this page delivers verified electrical specs, fail-safe mode behavior, CMTI immunity (≥60 kV/µs), and automotive-grade compatibility-critical for high-reliability isolated gate drive and battery management signal conditioning.
Technical Context
The SI8645BC-AS1 implements RF-based on/off keying across a silicon-dielectric isolation barrier, eliminating startup initialization and enabling robust noise immunity without optical degradation. Its four isolated channels are all input-side referenced (VDD1 side), with outputs on VDD2 side driven in parallel without internal enable control-confirmed by Table 3.2 showing "- / -" for EN1/EN2 operation.
It features Schmitt-trigger inputs (VT+ = 1.67 V typ, VT– = 1.23 V typ), 50 Ω nominal output impedance, and selectable default-low fail-safe mode (per ordering code "BC"). Safety certification includes UL 1577 (3.75 kVRMS), CSA 5A, and IEC 62368-1 basic insulation compliance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Isolation Rating | 3.75 kVRMS - meets reinforced insulation requirements for industrial equipment up to 300 VRMS working voltage per IEC 62368-1. |
| Max Data Rate | 150 Mbps - supports high-speed SPI, RS-485 transceiver control, and real-time ADC/DAC isolation without timing bottlenecks. |
| Propagation Delay | 8.0 ns typ - enables sub-10 ns timing-critical feedback in isolated DC-DC controllers and motor gate drivers. |
| Channel-Channel Skew | 0.4 ns typ - ensures synchronized sampling across multiple isolated sensor channels in precision measurement systems. |
| CMTI | 60 kV/µs min - suppresses false triggering during fast-switching events in SiC/GaN inverters and EV traction systems. |
| Supply Voltage Range | 2.375–5.5 V - allows direct interfacing with 3.3 V microcontrollers and 5 V legacy logic without level-shifting. |
| Fail-Safe Default | Low - guarantees safe deactivation of downstream power stages during VDD1 loss (e.g., primary-side brownout). |
Pinout & Package
Narrow-body SOIC-16 (NB SOIC-16) package with 1.27 mm pitch, RoHS-compliant, JEDEC MS-012 compliant, creepage ≥5.5 mm, clearance ≥5.5 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4 | VDD1 Power Supply | Input-side supply rail; bypass capacitor required between each VDD1 and GND1 for noise suppression. |
| 5, 7, 9, 11 | A1–A4 Inputs | CMOS/Schmitt-trigger inputs accepting 2.0–5.5 V logic; no external pull-ups needed for default-low operation. |
| 6, 8, 10, 12 | B1–B4 Outputs | Push-pull outputs with 50 Ω impedance; drive 15 pF loads at 150 Mbps with ≤4 ns rise/fall times. |
| 13, 14, 15, 16 | GND1, GND2, VDD2, GND2 | Split ground domains (GND1/GND2) and dual supplies (VDD1/VDD2) maintain galvanic isolation integrity. |
Key Features
| Feature | Design Value |
|---|---|
| RF-Based Isolation | Eliminates LED aging and temperature drift; enables 60-year lifetime at rated voltage without performance degradation. |
| Fail-Safe Output Mode | Guaranteed logic-low output during VDD1 loss-critical for disabling IGBTs/MOSFETs in overcurrent fault conditions. |
| Ultra-Low Power | 1.5 mA/channel at 1 Mbps (2.5 V), 3.5 mA/channel at 100 Mbps (2.5 V)-reduces thermal load in sealed enclosures. |
| High CMTI Immunity | 60 kV/µs minimum-prevents data corruption in noisy environments like variable-frequency drives and solar inverters. |
| Wide Temperature Range | –40 to +125 °C operation-qualified for under-hood automotive BMS and industrial PLC backplanes. |
Applications
| Motor Control Systems | Isolated Switch-Mode Supplies |
|---|---|
|
Use Scenario: Gate driver signal isolation in 3-phase inverter stacks using SiC MOSFETs. IC Role / Device Role / Timing Role: Transmits PWM signals across isolation barrier while rejecting common-mode dv/dt transients >50 kV/µs. Use Value: Prevents shoot-through failure via guaranteed low-state output during controller reset or supply dropout. |
Use Scenario: Feedback path isolation in 1 kW LLC resonant converters with 400 V DC bus. IC Role / Device Role / Timing Role: Transfers optocoupler-replacement error amplifier output with <10 ns delay and no startup latency. Use Value: Enables tight regulation bandwidth (>100 kHz) without phase lag introduced by opto-based solutions. |
| Industrial Automation | Battery Management Systems |
|
Use Scenario: Digital I/O isolation in PLC modules handling 24 V DC field signals. IC Role / Device Role / Timing Role: Provides four independent isolated input channels with Schmitt-trigger noise rejection. Use Value: Eliminates contact bounce and EMI-induced false triggers in factory-floor environments. |
Use Scenario: Cell voltage monitoring isolation in 800 V EV battery packs. IC Role / Device Role / Timing Role: Isolates ADC serial interface (SPI) between high-voltage stack monitor and low-voltage MCU. Use Value: Maintains 150 Mbps SPI clock integrity despite 100+ V/ns common-mode transients during cell balancing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad-channel digital isolator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SI8645BB-AS1 | 2.5 kVRMS isolation rating; same pinout, package, and timing specs. | Suitable for lower-risk industrial interfaces where 3.75 kV is not mandated by safety standards. | Select when cost optimization is prioritized and system-level creepage/clearance allows reduced isolation rating. |
| ADUM140D0BRZ | 5 kVRMS, 150 Mbps, but higher 10.5 ns max propagation delay and 10 mA/channel @ 100 Mbps (vs. 3.5 mA @ 2.5 V). | Better suited for medical-grade isolation where reinforced 5 kV is required, but less optimal for ultra-low-power designs. | Choose only if UL/IEC 60601-1 reinforced certification is mandatory and power budget permits higher current draw. |
Compared with SI8645BC-AS1, SI8645BB-AS1 reduces isolation margin but lowers BOM cost, while ADUM140D0BRZ adds 5 kV safety headroom at the expense of power efficiency and timing precision-making SI8645BC-AS1 optimal for cost-sensitive, thermally constrained 3.75 kV industrial systems.
Availability
SI8645BC-AS1 is available at Aetrix Electronics and suitable for industrial motor control, isolated power supply feedback, and battery management systems requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for SI8645BC-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 semiconductor company specializing in analog and mixed-signal connectivity solutions, with leadership in RF, timing, and isolation technologies.
The Si864x family was engineered to replace optocouplers in high-reliability industrial and automotive systems, delivering superior speed, longevity, and noise immunity through RF-based CMOS isolation.
FAQ
What is the isolation voltage rating of the SI8645BC-AS1?
The SI8645BC-AS1 has a certified 3.75 kVRMS isolation rating per UL 1577 and IEC 62368-1 basic insulation requirements. This rating applies to the narrow-body SOIC-16 package with ≥5.5 mm creepage and clearance, validated for continuous operation at up to 300 VRMS working voltage in industrial environments.
Does the SI8645BC-AS1 require external pull-up or pull-down resistors on its inputs?
No. The SI8645BC-AS1 features integrated 2 µA pull-downs on all input pins (A1–A4) due to its default-low fail-safe configuration ("BC" suffix). External resistors are unnecessary unless specific system-level noise margins demand additional hysteresis beyond the built-in Schmitt trigger thresholds (VT+ = 1.67 V, VT– = 1.23 V).
How does the SI8645BC-AS1 behave during input-side power loss?
When VDD1 drops below UVLO– (1.88 V min), the SI8645BC-AS1 forces all outputs (B1–B4) to logic low within 12 ns (tSD), maintaining safe shutdown of downstream circuitry. This behavior is intrinsic to the "BC" ordering option and requires no external supervision circuitry.
Can the SI8645BC-AS1 be used in automotive applications?
Yes. The SI8645BC-AS1 is qualified to AEC-Q100 Grade 1 (–40 to +125 °C) and supported with AIAG-compliant PPAP documentation. While not automotive-grade (which would carry "-A" suffix), its electrical specs, thermal range, and reliability meet requirements for non-safety-critical automotive subsystems like onboard charger status signaling and HVAC control isolation.
What is the maximum recommended capacitive load for SI8645BC-AS1 outputs?
The SI8645BC-AS1 is characterized for 15 pF capacitive load per output channel at 150 Mbps. Driving higher capacitance (e.g., >25 pF) increases rise/fall times beyond 4 ns and may cause pulse width distortion >4.5 ns, violating timing margins in high-speed SPI or JESD204B links. Controlled-impedance PCB routing and series termination are recommended for loads exceeding 15 pF.
SI8645BC-AS1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Skyworks Solutions Inc.
- Series:
- Si864x
- 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:
- 4
- Inputs - Side 1/Side 2:
- 4/0
- 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
SI8645BC-AS1 FAQ
1.How can I place an order for SI8645BC-AS1 through Aetrix?
Please submit a Request for Quotation (RFQ) for SI8645BC-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 SI8645BC-AS1 reliable?
The price and inventory of SI8645BC-AS1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI8645BC-AS1 is usually 5 days.
3.What payment methods are accepted for SI8645BC-AS1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI8645BC-AS1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SI8645BC-AS1?
SI8645BC-AS1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SI8645BC-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 SI8645BC-AS1?
For technical support, including SI8645BC-AS1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI8645BC-AS1 requirements.
6.How does Aetrix verify that SI8645BC-AS1 is sourced from the original manufacturer or authorized distributors?
All SI8645BC-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 SI8645BC-AS1 meets industry standards.
7.What is the process for return or replacement of SI8645BC-AS1?
All SI8645BC-AS1 units undergo pre-shipment inspection (PSI). If there is an issue with SI8645BC-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 SI8645BC-AS1 part is unused and in its original packaging.
Return procedure for SI8645BC-AS1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SI8645BC-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
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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