My Inquiry
My Account
Skyworks Solutions Inc. SI8651AB-AS1
- Part No.:
- SI8651AB-AS1
- Manufacturer:
- Skyworks Solutions Inc.
- Category:
- Digital Isolators
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SI8651AB-AS1.pdf
- Description:
- AUTOMOTIVE 2.5 KV 4 FORWARD & 1
- Quantity:
- Payment:
- Shipping:
Inventory:3,608
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SI8651AB-AS1 from Skyworks is a five-channel, automotive-grade digital isolator with 4 input channels on VDD1 side and 1 output channel 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 fail-safe low-default output, and ultra-low power consumption (1.5 mA/channel at 1 Mbps, 2.5 V).
For engineers reviewing the SI8651AB-AS1 datasheet, SI8651AB-AS1 pinout, SI8651AB-AS1 application, or SI8651AB-AS1 equivalent, this page delivers verified technical context, precise timing specs (8 ns typical propagation delay, 0.5 ns channel skew), fail-safe behavior under undervoltage, and automotive-qualified reliability per AEC-Q100.
Technical Context
The SI8651AB-AS1 implements RF-based on/off keying across a semiconductor isolation barrier-no startup initialization required. Its dual-supply architecture (VDD1/VDD2) supports independent 2.5–5.5 V operation per side, with separate UVLO monitors ensuring robust behavior during asymmetric power sequencing.
It integrates two enable inputs (EN1 on Side A, EN2 on Side B) enabling independent tri-state control of the single output channel (A5) and four output channels (B1–B4). The device uses internal 2 µA pull-ups on enable pins and supports fail-safe default-low output via ordering option, confirmed in Table 1.1.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Channels | 5 total: 4 unidirectional inputs (Side A), 1 unidirectional output (Side B); enables isolated signal routing from controller to peripheral with direction separation. |
| Max Data Rate | 150 Mbps - supports high-speed serial interfaces including SPI clock lines, isolated UART, and fast sensor data links without timing bottlenecks. |
| Propagation Delay | 8 ns typical - ensures sub-10 ns latency critical for real-time motor control feedback loops and closed-loop timing systems. |
| Isolation Rating | 2.5 kVRMS - certified to UL 1577, VDE 0884-10, CSA 5A, and IEC 62368-1 reinforced insulation standards for industrial and automotive safety compliance. |
| Supply Voltage | 2.5–5.5 V per side - allows direct interfacing with 3.3 V microcontrollers and 5 V analog subsystems without level-shifting. |
| Fail-Safe Default | Low-output state during VDD1 loss - prevents unintended activation in battery management or OBC systems when primary supply fails. |
| CMTI | 50 kV/µs - rejects high dv/dt noise in traction inverters and SMPS, maintaining signal integrity in >1 kV switching environments. |
Pinout & Package
SI8651AB-AS1 is housed in a RoHS-compliant narrow-body SOIC-16 package (NB SOIC-16), 10.3 mm × 7.5 mm footprint, 1.5 mm height, with creepage/clearance ≥8.0 mm per regulatory tables.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD1 | Input-side power supply | Supplies 2.5–5.5 V to input logic and transmitter; UVLO threshold 2.24 V (typical) ensures clean startup before data transfer. |
| GND1 | Input-side ground reference | Return path for VDD1; must be separated from GND2 by ≥8 mm creepage for full 2.5 kVRMS isolation integrity. |
| INA1–INA4 | Input channels (Side A) | Schmitt-triggered digital inputs accepting 0–VDD1 logic; hysteresis 0.44 V (typical) rejects EMI in noisy motor drive environments. |
| EN1 | Enable for A5 output | Active-high control (2 µA internal pull-up); drives A5 into high-impedance when low - enables multiplexing or safe shutdown. |
| VDD2 | Output-side power supply | Independent 2.5–5.5 V supply for receiver and output drivers; enables galvanic separation between domains. |
| GND2 | Output-side ground reference | Return path for VDD2; electrically isolated from GND1; defines output logic levels referenced to local ground. |
| OUTB1–OUTB4 | Output channels (Side B) | CMOS-compatible outputs with 50 Ω nominal impedance; drive 15 pF loads at 150 Mbps with <4 ns rise/fall times. |
| EN2 | Enable for B1–B4 outputs | Active-high control (2 µA internal pull-up); disables all four B-side outputs simultaneously into high-Z state. |
| A5 | Single output from Side A | Directional output driven by INA1–INA4 logic; enabled only when EN1 = high; default-low during VDD1 loss per ordering option. |
Key Features
| Feature | Design Value |
|---|---|
| RF-based isolation barrier | Eliminates LED aging and temperature drift issues of optocouplers; maintains stable timing and power over –40 to +125 °C life cycle. |
| Selectably fail-safe output | Factory-configured low-default state ensures safe deactivation of downstream actuators or gate drivers during primary supply failure. |
| Tri-state enable architecture | Dual EN pins allow independent control of A5 and B1–B4 groups - supports dynamic bus sharing and fault-isolation in multi-peripheral systems. |
| Ultra-low power at 1 Mbps | 1.5 mA/channel @ 2.5 V enables always-on monitoring in battery-powered BMS nodes without compromising runtime. |
| AEC-Q100 qualified | Automotive-grade process flow, PPAP documentation, IMDS/CAMDS support, and zero-defect methodology ensure suitability for OBC and traction inverter use. |
Applications
| On-Board Charger (OBC) | Battery Management System (BMS) |
|---|---|
|
Use Scenario: Isolating MCU SPI commands and status signals between low-voltage control domain and 400–800 V DC-link power stage. IC Role / Device Role / Timing Role: SI8651AB-AS1 transmits isolated gate driver enable/disable signals and ADC readbacks with <8 ns delay and 50 kV/µs CMTI immunity. Use Value: Prevents latch-up and false triggering during high dv/dt transients in SiC/GaN-based OBC topologies while meeting ASIL-B functional safety requirements. |
Use Scenario: Communicating cell voltage and temperature measurements from isolated sensing front-end to main BMS controller across 2.5 kVRMS barrier. IC Role / Device Role / Timing Role: SI8651AB-AS1 carries isolated I²C or SPI data from isolated ADCs, using its 4-input/1-output configuration to consolidate telemetry streams. Use Value: Enables compact, low-power telemetry isolation with fail-safe low-default output - avoids erroneous cell disconnect commands during brownout events. |
| Traction Inverter Control | Industrial Motor Drive |
|
Use Scenario: Transmitting PWM dead-time control signals and fault feedback between inverter MCU and isolated gate driver ICs in EV powertrain. IC Role / Device Role / Timing Role: SI8651AB-AS1 routes isolated PWM enable and DESAT fault signals with sub-10 ns propagation delay and <0.5 ns channel skew. Use Value: Guarantees precise timing alignment across multiple gate drivers, minimizing shoot-through risk and improving inverter efficiency at 10–20 kHz switching frequencies. |
Use Scenario: Isolating encoder position data and PLC command signals in servo drives operating in electrically noisy factory environments. IC Role / Device Role / Timing Role: SI8651AB-AS1 interfaces with incremental encoders and fieldbus controllers, leveraging Schmitt-trigger inputs and 50 kV/µs CMTI. Use Value: Maintains position accuracy and command fidelity despite 400 VAC line noise and variable-frequency drive harmonics, reducing motion jitter and positioning errors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar digital isolator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SI8651BB-AS1 | Same pinout, package, and channel count; differs only in default output state (low vs. high). SI8651AB-AS1 has fail-safe low; SI8651BB-AS1 has fail-safe high. | Used where active-high enable or reset is required (e.g., certain gate driver ICs expecting high-enable logic). | Select SI8651AB-AS1 when system safety requires deactivation on input-side power loss; choose SI8651BB-AS1 for high-enable compatibility. |
| ADUM141E0BRZ | 4-channel, not 5-channel; no dedicated A5 output; different enable architecture (single EN); 25 kV/µs CMTI vs. 50 kV/µs. | Limited to 4-signal isolation; unsuitable for asymmetric 4-in/1-out routing or high-noise traction inverter use. | Consider only for cost-sensitive, lower-noise industrial applications where channel count and CMTI margin are non-critical. |
Compared with SI8651BB-AS1, SI8651AB-AS1 provides guaranteed low-default behavior during VDD1 loss - critical for fail-safe gate driver disable. Against ADUM141E0BRZ, SI8651AB-AS1 adds a fifth isolated path and doubles CMTI performance, enabling robust operation in automotive power electronics.
Availability
SI8651AB-AS1 is available at Aetrix Electronics and suitable for on-board chargers, battery management systems, and traction inverters requiring stable component supply, automotive qualification, and long-term lifecycle support.
Supply support for SI8651AB-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 high-performance analog semiconductors, specializing in RF, timing, and isolation technologies for communications, automotive, and industrial markets.
The Si865x family was designed specifically for automotive and industrial isolation needs - delivering AEC-Q100 qualification, reinforced insulation, and RF-based reliability superior to optocouplers in harsh EMI and thermal environments.
FAQ
What is the isolation rating and safety certification of SI8651AB-AS1?
SI8651AB-AS1 is rated for 2.5 kVRMS isolation and certified to UL 1577, VDE 0884-10, CSA Component Notice 5A, and IEC 62368-1 reinforced insulation standards. These certifications validate its use in automotive and industrial systems requiring functional safety up to ASIL-B and SIL-2 levels. The narrow-body SOIC-16 package meets creepage and clearance requirements for 2.5 kVRMS working voltage.
Does SI8651AB-AS1 require external startup initialization or configuration?
No, SI8651AB-AS1 requires no startup initialization or configuration. It begins transmitting valid data within 40 µs of VDD1/VDD2 reaching UVLO threshold (2.24 V typical), with outputs following input states immediately after start-up time. This zero-configuration behavior simplifies firmware design and eliminates boot-time uncertainty in safety-critical automotive systems.
How does the fail-safe mode operate in SI8651AB-AS1?
In SI8651AB-AS1, the fail-safe mode is factory-set to default-low output on the A5 channel when VDD1 is unpowered but VDD2 remains active. This behavior is hard-coded per ordering option and ensures downstream circuits (e.g., gate drivers) remain safely disabled during primary supply faults - a key requirement in OBC and BMS designs.
What are the enable pin functions for SI8651AB-AS1?
SI8651AB-AS1 has two enable inputs: EN1 controls the A5 output (Side A), and EN2 controls the B1–B4 outputs (Side B). Both are active-high with 2 µA internal pull-ups. When asserted, they enable normal output drive; when low, they place respective outputs in high-impedance state - enabling dynamic bus control and fault containment without external logic.
Is SI8651AB-AS1 compatible with 2.5 V, 3.3 V, and 5 V logic families?
Yes, SI8651AB-AS1 supports 2.5–5.5 V operation on both VDD1 and VDD2 sides, making it interoperable with 2.5 V FPGAs, 3.3 V microcontrollers, and 5 V analog peripherals. Input thresholds (VT+ = 1.67 V typ, VT– = 1.23 V typ) and output drive strength (VOH = VDD–0.4 V, VOL = 0.2 V max) ensure reliable interfacing across all three logic families without level shifters.
SI8651AB-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:
- No
- Number of Channels:
- 5
- Inputs - Side 1/Side 2:
- 4/1
- 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
SI8651AB-AS1 FAQ
1.How can I place an order for SI8651AB-AS1 through Aetrix?
Please submit a Request for Quotation (RFQ) for SI8651AB-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 SI8651AB-AS1 reliable?
The price and inventory of SI8651AB-AS1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI8651AB-AS1 is usually 5 days.
3.What payment methods are accepted for SI8651AB-AS1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI8651AB-AS1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SI8651AB-AS1?
SI8651AB-AS1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SI8651AB-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 SI8651AB-AS1?
For technical support, including SI8651AB-AS1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI8651AB-AS1 requirements.
6.How does Aetrix verify that SI8651AB-AS1 is sourced from the original manufacturer or authorized distributors?
All SI8651AB-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 SI8651AB-AS1 meets industry standards.
7.What is the process for return or replacement of SI8651AB-AS1?
All SI8651AB-AS1 units undergo pre-shipment inspection (PSI). If there is an issue with SI8651AB-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 SI8651AB-AS1 part is unused and in its original packaging.
Return procedure for SI8651AB-AS1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SI8651AB-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
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
