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Skyworks Solutions Inc. SI8645BB-AS1
- Part No.:
- SI8645BB-AS1
- Manufacturer:
- Skyworks Solutions Inc.
- Category:
- Digital Isolators
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SI8645BB-AS1.pdf
- Description:
- AUTOMOTIVE 2.5 KV 4-CHANNEL DIGI
- Quantity:
- Payment:
- Shipping:
Inventory:4,701
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Product details
Overview
SI8645BB-AS1 from Skyworks is a quad-channel, unidirectional digital isolator with 4 input channels on VDD1 side and 0 on VDD2 side, rated for 2.5 kVRMS isolation, 150 Mbps data rate, and –40 to 125 °C operation. It features Schmitt-trigger inputs, tri-state outputs with enable control, selectable low-fail-safe default output, and ultra-low power consumption (1.6 mA/channel @ 1 Mbps, 5 V).
For engineers reviewing the SI8645BB-AS1 datasheet, SI8645BB-AS1 pinout, SI8645BB-AS1 application, or SI8645BB-AS1 equivalent, this page delivers verified electrical specs, SOIC-16 narrow-body package details, fail-safe mode behavior, and automotive-grade compatibility per AEC-Q100 - critical for isolated motor control, battery management, and industrial power supply designs.
Technical Context
The SI8645BB-AS1 implements RF-based on/off keying across a silicon dioxide isolation barrier, eliminating startup initialization and enabling robust noise immunity without optical degradation. Its architecture supports independent undervoltage lockout (UVLO) on both sides, with VDDUV+ = 2.24 V (typ) and hysteresis of 70 mV (typ), ensuring stable operation during brownout conditions.
All four channels are input-only on Side A (VDD1) and output-only on Side B (VDD2), with no enable pins (EN1/EN2 omitted per Si8645 family). Outputs default low during power loss when VDD1 is unpowered but VDD2 remains active - a factory-configured fail-safe mode confirmed in the Ordering Guide.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Isolation Rating | 2.5 kVRMS - meets reinforced insulation requirements per IEC 62368-1 and UL 1577 for safety-critical industrial and automotive systems. |
| Max Data Rate | 150 Mbps - enables high-speed serial interfaces such as SPI, RS-485, and isolated CAN FD transceivers without timing bottlenecks. |
| Propagation Delay | 8 ns (typ) - ensures sub-10 ns timing alignment across isolated domains, critical for real-time motor control and ADC sampling synchronization. |
| Channel-Channel Skew | 0.5 ns (typ) - guarantees tightly matched signal arrival across all four isolated channels, minimizing inter-channel timing errors in multi-signal feedback loops. |
| Supply Voltage Range | 2.5–5.5 V - supports direct interfacing with 3.3 V microcontrollers and 5 V legacy logic without level-shifting circuitry. |
| CMTI | 60 kV/µs (typ) - suppresses false triggering in high-dV/dt environments like inverters and switching power supplies. |
| Fail-Safe Default | Low - output pins drive logic low when VDD1 is unpowered, preventing undefined states in fault-tolerant BMS and OBC systems. |
Pinout & Package
SI8645BB-AS1 is housed in a RoHS-compliant narrow-body SOIC-16 package (5.3 mm width), with creepage/clearance optimized for 2.5 kVRMS working voltage. Pin assignments follow standard Si864x channel mapping with dedicated VDD1/GND1 and VDD2/GND2 pairs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4 | Input A1–A4 | Unidirectional digital inputs referenced to VDD1/GND1; Schmitt-triggered for >0.44 V hysteresis and noise rejection. |
| 5, 6 | VDD1, GND1 | Primary-side power supply (2.5–5.5 V); bypass capacitor required at pin 5 for stable operation. |
| 7–10 | Output B1–B4 | Isolated outputs referenced to VDD2/GND2; tri-state capable only via external control (no EN pin on SI8645). |
| 11, 12 | VDD2, GND2 | Secondary-side power supply (2.5–5.5 V); independent of VDD1, enabling galvanic separation of power domains. |
| 13–16 | GND1, VDD1, GND2, VDD2 (redundant) | Additional ground and supply pins for improved EMI performance and thermal dissipation in high-density layouts. |
Key Features
| Feature | Design Value |
|---|---|
| RF-based isolation barrier | Silicon dioxide dielectric enables 60-year lifetime at rated voltage and eliminates LED aging concerns of optocouplers. |
| Fail-safe low default mode | Guarantees defined logic-low output state during primary-side power loss - essential for safe shutdown in traction inverters. |
| Ultra-low power at 1 Mbps | 1.6 mA per channel @ 5 V reduces thermal load in sealed enclosures and extends battery runtime in portable medical devices. |
| High CMTI (60 kV/µs) | Prevents data corruption in noisy motor drive environments where common-mode transients exceed 50 kV/µs. |
| No start-up initialization | Outputs become valid within 40 µs of VDD application - eliminates boot-time delays in real-time PLC and servo controllers. |
Applications
| Industrial Motor Control | Automotive Battery Management |
|---|---|
Use Scenario: Isolating gate driver signals and current-sense feedback in 3-phase inverter stacks for HVAC compressors and EV traction motors. IC Role / Device Role / Timing Role: Quad-channel isolator transmitting PWM commands and fault status across high-voltage barriers with <8 ns propagation delay. Use Value: Enables precise dead-time control and fast overcurrent response (<12 ns default-output assertion) while meeting IEC 61800-5-1 reinforced insulation requirements. |
Use Scenario: Signal isolation between MCU and cell monitoring ICs in high-voltage battery packs (up to 900 VDC). IC Role / Device Role / Timing Role: Transmitting voltage/temperature telemetry and pack-status alerts across isolation boundary with fail-safe low default. Use Value: Prevents erroneous high-side activation during partial power loss, supporting ASIL-B functional safety compliance in ISO 26262 systems. |
| Isolated Switch-Mode Power Supply | Medical Isolated Data Acquisition |
Use Scenario: Feedback path isolation in 1–3 kW AC/DC converters using LLC or phase-shifted full-bridge topologies. IC Role / Device Role / Timing Role: Delivering isolated error amplifier output and synchronous rectifier timing signals with <0.5 ns channel skew. Use Value: Maintains tight regulation bandwidth and improves transient response by eliminating timing jitter-induced loop instability. |
Use Scenario: Isolating analog front-end digitization paths in patient-connected ECG and EEG monitors. IC Role / Device Role / Timing Role: Transmitting isolated SPI clock/data between isolated ADC and host processor under IEC 60601-1 requirements. Use Value: Achieves 2.5 kVRMS reinforced insulation and 60 kV/µs CMTI to prevent leakage currents and ensure patient safety in Class BF applications. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar digital isolator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ADUM140D0BRZ | 4-channel, 150 Mbps, 2.5 kVRMS, SOIC-16 NB; uses iCoupler magnetic coupling; higher 3.2 mA/channel @ 1 Mbps (5 V). | Lacks AEC-Q100 qualification; not automotive-grade; lower CMTI (35 kV/µs typ). | Preferred for cost-sensitive industrial designs where automotive qualification is unnecessary. |
| ISO6741QDWR | 4-channel, 50 Mbps, 3.75 kVRMS, SOIC-16 NB; TI's capacitive isolator; 1.8 mA/channel @ 1 Mbps (3.3 V); AEC-Q100 Grade 1. | Lower data rate limits use in high-speed SPI or isolated USB; higher isolation rating suits medical mains-connected equipment. | Chosen when 3.75 kVRMS and automotive qualification are mandatory but 150 Mbps is not required. |
Compared with ADUM140D0BRZ and ISO6741QDWR, SI8645BB-AS1 uniquely combines AEC-Q100 Grade 0 qualification (–40 to 125 °C), 150 Mbps speed, 2.5 kVRMS rating, and fail-safe low default in a narrow-body SOIC - making it optimal for space-constrained, high-reliability automotive and industrial isolation nodes.
Availability
SI8645BB-AS1 is available at Aetrix Electronics and suitable for industrial motor control, automotive battery management systems, and isolated switch-mode power supplies requiring stable component supply, long-term lifecycle support, and automotive-grade traceability.
Supply support for SI8645BB-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 designed specifically for high-reliability, high-speed digital isolation in automotive, industrial, and medical systems - emphasizing low power, precise timing, and safety certification readiness.
FAQ
What is the isolation rating and safety certification status of SI8645BB-AS1?
SI8645BB-AS1 is rated for 2.5 kVRMS isolation and certified to UL 1577, CSA Component Acceptance Notice 5A, VDE 0884-10 (basic insulation), and IEC 62368-1. It meets reinforced insulation requirements for industrial and automotive end-equipment, including AEC-Q100 Grade 0 qualification for operation from –40 to 125 °C.
Does SI8645BB-AS1 support tri-state outputs, and how is output control implemented?
SI8645BB-AS1 does not include enable (EN) pins - unlike Si8640/Si8641 variants, the Si8645 family has no EN1 or EN2 terminals. Outputs B1–B4 are always active when VDD2 is powered and follow inputs A1–A4. Tri-state functionality must be implemented externally using series MOSFETs or bus switches, as the SI8645BB-AS1 itself provides no internal output disable capability.
What is the default output state of SI8645BB-AS1 during power loss on the input side?
SI8645BB-AS1 is configured as a "low-fail-safe" device: when VDD1 is unpowered but VDD2 remains active, outputs B1–B4 drive logic low. This behavior is fixed by ordering code "BB" and ensures predictable shutdown in battery management and motor control systems where undefined outputs could cause hazardous conditions.
How does the power consumption of SI8645BB-AS1 compare at different data rates and supply voltages?
At 1 Mbps and 5 V, SI8645BB-AS1 draws 1.6 mA per channel (6.4 mA total); at 100 Mbps and 5 V, it draws 5.5 mA per channel (22 mA total). At 2.5 V, consumption drops to 1.5 mA/channel @ 1 Mbps and 3.5 mA/channel @ 100 Mbps - enabling energy-efficient operation in battery-powered medical and portable industrial tools.
Is SI8645BB-AS1 compatible with 3.3 V microcontrollers and 5 V peripheral logic simultaneously?
Yes. SI8645BB-AS1 supports independent 2.5–5.5 V supplies on both sides: VDD1 can be 3.3 V (for MCU interface) while VDD2 is 5 V (for driving optocoupler-replacement logic or gate drivers). Input thresholds (VT+ = 1.67 V typ, VT– = 1.23 V typ) ensure reliable detection of 3.3 V logic levels, and output VOH/VOL meet 5 V TTL/CMOS specifications.
SI8645BB-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:
- 2500Vrms
- 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
SI8645BB-AS1 FAQ
1.How can I place an order for SI8645BB-AS1 through Aetrix?
Please submit a Request for Quotation (RFQ) for SI8645BB-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 SI8645BB-AS1 reliable?
The price and inventory of SI8645BB-AS1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI8645BB-AS1 is usually 5 days.
3.What payment methods are accepted for SI8645BB-AS1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI8645BB-AS1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SI8645BB-AS1?
SI8645BB-AS1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SI8645BB-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 SI8645BB-AS1?
For technical support, including SI8645BB-AS1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI8645BB-AS1 requirements.
6.How does Aetrix verify that SI8645BB-AS1 is sourced from the original manufacturer or authorized distributors?
All SI8645BB-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 SI8645BB-AS1 meets industry standards.
7.What is the process for return or replacement of SI8645BB-AS1?
All SI8645BB-AS1 units undergo pre-shipment inspection (PSI). If there is an issue with SI8645BB-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 SI8645BB-AS1 part is unused and in its original packaging.
Return procedure for SI8645BB-AS1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SI8645BB-AS1 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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