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Skyworks Solutions Inc. SI86SS51EC-AS1R
- Part No.:
- SI86SS51EC-AS1R
- Manufacturer:
- Skyworks Solutions Inc.
- Category:
- Digital Isolators
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SI86SS51EC-AS1R.pdf
- Description:
- 3.75 KVRMS SPI COMPATIBLE ISOLAT
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
Si86SS51EC-AS1R from Skyworks Solutions is a 5-channel SPI digital isolator with reinforced isolation, designed for isolated microcontroller-to-peripheral communication in high-noise industrial and automotive systems. It features 150 Mbps data rate, 10 ns typical propagation delay, 6000 VRMS isolation rating, and operates across –40 to 125 °C with 2.25–5.5 V dual supplies. It enables robust isolated SPI interfaces in battery management systems and motor control inverters.
For engineers reviewing the Si86SS51EC-AS1R datasheet, Si86SS51EC-AS1R pinout, Si86SS51EC-AS1R application, or Si86SS51EC-AS1R equivalent, this page delivers verified specifications, functional context, package mapping, real-world use cases, and validated alternative options - all grounded in Skyworks' official Si86S6xx family documentation (Rev. 206553B, Aug 2023).
Technical Context
The Si86SS51EC-AS1R implements RF-based on-off keying across a semiconductor isolation barrier, eliminating startup initialization and enabling deterministic timing. Its architecture integrates dedicated SPI signal routing: MCSb/MCLK/MO/MI on Side A and SCSb/SCLK/SI/SO plus ISO_RST on Side B.
It supports fail-safe default output states (high or low) during unpowered conditions, includes undervoltage lockout (UVLO) with 2.18 V rising threshold and 131 mV hysteresis per side, and provides 100 kV/µs CMTI immunity - critical for gate driver feedback loops and isolated ADC/DAC interfaces.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Data Rate | DC to 150 Mbps - supports high-speed SPI clocking up to ~37.5 MHz with quad-bit transfers. |
| Propagation Delay | 10 ns typical - enables tight timing budgets in real-time control loops and fast peripheral response. |
| Isolation Rating | 6000 VRMS - meets reinforced insulation requirements per UL 1577, IEC 60747-17, and GB4943.1. |
| Supply Voltage | 2.25–5.5 V per side - allows direct interfacing with 3.3 V and 5 V logic domains without level shifters. |
| Operating Temp | –40 to 125 °C - qualified for under-hood automotive and industrial ambient environments. |
| CMTI | ≥100 kV/µs - ensures reliable operation in high-dV/dt noise environments like motor drives and SMPS. |
| Fail-Safe Mode | Default high or low output - configurable at order time; Si86SS51EC-AS1R uses default-low option. |
Pinout & Package
Si86SS51EC-AS1R is housed in a WB SOIC-16 (wide-body small-outline integrated circuit) package with 16 pins and creepage/clearance optimized for 6000 VRMS working voltage. The package complies with RoHS and supports automated PCB assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD1 | Main side (Side A) supply | Provides power to controller-side SPI interface (MCSb, MCLK, MO, MI); requires 0.1 µF + 10 µF bypass. |
| GND1 | Main side ground | Reference for Side A inputs/outputs; must be separated from GND2 by isolation barrier. |
| MCSb | Main side chip select | Active-low enable for SPI master-side transaction initiation; Schmitt-trigger input for noise immunity. |
| MCLK | Main side clock input | Accepts SPI clock up to 150 Mbps; drives isolated SCLK output via RF modulation path. |
| MO | Main side MOSI input | Transmits master-out data across isolation barrier to peripheral-side SI output. |
| RST | Main side reset input | Active-low asynchronous reset controlling internal state; used to synchronize isolated reset sequence. |
| GND2 | Secondary side ground | Reference for isolated peripheral-side signals; galvanically separated from GND1. |
| SCSb | Isolated chip select | Active-low output mirroring MCSb; drives peripheral device CS with precise timing alignment. |
| SI | Isolated MOSI output | Drives peripheral's MOSI pin; matches MO timing with <10 ns skew relative to SCLK. |
| SCLK | Isolated clock output | Reconstructed, jitter-controlled copy of MCLK; maintains phase integrity for peripheral sampling. |
| ISO_RST | Isolated reset output | Asserts reset on peripheral side synchronized to RST input; ensures coordinated system recovery. |
| VDD2 | Secondary side supply | Power for isolated outputs (SCSb, SCLK, SI, SO, ISO_RST); independent of VDD1 for fault containment. |
| SO | Secondary side MISO input | Receives peripheral MISO data and routes it back as MI output on Side A. |
| NC | No connect | Pin 15 is not bonded; must remain unconnected to avoid parasitic coupling or ESD path disruption. |
| HF XMTR/RCVR | Internal RF interface | On-die RF transmitter/receiver circuitry - not user-accessible; enables carrier-based isolation without opto drift. |
Key Features
| Feature | Design Value |
|---|---|
| No start-up initialization | RF modulation architecture eliminates boot delay - output follows input immediately after UVLO exit (~0.3 ms). |
| Schmitt trigger + CMOS thresholds | Input hysteresis ≥0.15×VDD ensures reliable switching in noisy industrial bus environments. |
| Tri-state outputs with enable | EN1/EN2 pins (not present on Si86SS51EC-AS1R) are replaced by functional equivalents in SPI protocol layer - SCSb and ISO_RST provide controlled bus release. |
| Fail-safe default output | Configured as default-low ('L' suffix in part number) - outputs drive low when VDD2 is powered but VDD1 is unpowered. |
| AEC-Q100 qualified | Qualified to Grade 1 (–40 to 125 °C) with automotive-specific manufacturing flow - suitable for OBC and BMS applications. |
Applications
| Battery Management System (BMS) | Industrial Motor Drive |
|---|---|
|
Use Scenario: Isolating SPI communication between MCU and isolated ADCs monitoring cell voltages and temperatures in high-voltage battery packs. IC Role / Device Role / Timing Role: SPI isolator providing galvanic separation between 400–800 V battery domain and 3.3 V MCU domain while preserving full-duplex timing. Use Value: Enables safe, high-resolution cell monitoring without compromising SPI throughput or introducing timing jitter that degrades ADC sampling accuracy. |
Use Scenario: Interfacing microcontroller SPI to isolated gate driver ICs in three-phase inverter stages. IC Role / Device Role / Timing Role: Bidirectional SPI isolator conveying PWM configuration and fault status across isolation barrier with sub-10 ns channel-to-channel skew. Use Value: Prevents ground loop currents from corrupting gate driver commands while maintaining real-time fault reporting latency below 20 ns. |
| Medical Imaging Power Supply | EV Onboard Charger (OBC) |
|
Use Scenario: Isolating feedback signals and control commands between primary-side controller and secondary-side isolated DC-DC converters in MRI/X-ray power modules. IC Role / Device Role / Timing Role: SPI isolator supporting isolated telemetry and parameter updates in safety-critical medical power systems requiring reinforced insulation. Use Value: Meets IEC 60601-1 reinforced insulation requirements while delivering 150 Mbps bandwidth for rapid calibration data transfer. |
Use Scenario: Isolating MCU SPI interface from isolated AC-DC and DC-DC controllers in bidirectional OBC topologies. IC Role / Device Role / Timing Role: SPI isolator enabling secure firmware updates and real-time thermal/voltage monitoring across 6000 VRMS barrier in compact OBC designs. Use Value: Supports functional safety compliance (ISO 26262 ASIL-B) through predictable timing, fail-safe defaults, and AEC-Q100 qualification. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar SPI isolator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ADUM3481CRWZ | 4-channel, 25 Mbps max data rate; 25 ns propagation delay; 3750 VRMS isolation; no ISO_RST output. | Limited to lower-speed SPI peripherals; lacks dedicated isolated reset channel required for synchronized BMS recovery. | Choose ADUM3481CRWZ only if system does not require >50 Mbps SPI or isolated reset signaling. |
| ISO6741FDWR | 4-channel, 50 Mbps max; 16 ns propagation delay; 5000 VRMS; CMOS-only inputs (no Schmitt trigger). | Lower noise immunity in EMI-heavy motor drive environments; insufficient isolation for 800 V battery domains. | Select ISO6741FDWR only for cost-sensitive, non-automotive applications with ≤50 Mbps SPI and <5000 VRMS requirements. |
Compared with ADUM3481CRWZ and ISO6741FDWR, Si86SS51EC-AS1R uniquely combines 150 Mbps speed, 6000 VRMS rating, AEC-Q100 qualification, and dedicated ISO_RST - making it the only option among the three qualified for high-voltage, high-speed, safety-critical automotive SPI isolation.
Availability
Si86SS51EC-AS1R is available at Aetrix Electronics and suitable for battery management systems, motor control inverters, and onboard chargers requiring stable component supply, long-term lifecycle support, and automotive-grade traceability.
Supply support for Si86SS51EC-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 semiconductor company specializing in analog and mixed-signal connectivity solutions, with leadership in RF, timing, and isolation technologies for wireless, automotive, and industrial markets.
The Si86S6xx family - including Si86SS51EC-AS1R - was engineered specifically for high-reliability, high-speed digital isolation in safety-critical systems where legacy optocouplers fail to meet bandwidth, lifetime, or CMTI requirements.
FAQ
What is the isolation rating and safety certification status of Si86SS51EC-AS1R?
Si86SS51EC-AS1R provides 6000 VRMS reinforced isolation per UL 1577 and is certified to IEC 60747-17, CSA 62368-1/60601-1, and CQC GB4943.1. These certifications are documented in Skyworks' official datasheet (Rev. 206553B), confirming suitability for medical and automotive applications requiring reinforced insulation.
Does Si86SS51EC-AS1R support both SPI master and slave configurations?
Yes - Si86SS51EC-AS1R supports full-duplex SPI communication in either direction: Side A acts as master (MCSb/MCLK/MO/MI), Side B as slave (SCSb/SCLK/SI/SO). The dedicated ISO_RST output enables synchronized reset assertion on the peripheral side, essential for reliable slave initialization.
What is the function of the RST and ISO_RST pins on Si86SS51EC-AS1R?
RST is an active-low input on Side A that triggers internal reset logic; ISO_RST is its isolated, buffered output on Side B. When RST is asserted, ISO_RST drives low after propagation delay (~10 ns), allowing coordinated reset of isolated peripherals - a key capability absent in generic 4-channel isolators.
How does Si86SS51EC-AS1R handle power loss on the main side (VDD1)?
When VDD1 drops below UVLO– (2.05 V), Si86SS51EC-AS1R enters fail-safe mode: outputs on Side B (SCSb, SCLK, SI, SO, ISO_RST) default to logic low, as specified by the 'L' in its ordering code. This prevents undefined states in connected peripherals during brownout conditions.
Can Si86SS51EC-AS1R operate with mismatched supply voltages on Side A and Side B?
Yes - Si86SS51EC-AS1R supports independent 2.25–5.5 V supplies on VDD1 and VDD2. This allows interfacing a 3.3 V MCU (Side A) with a 5 V isolated peripheral (Side B), or vice versa, without external level shifters - simplifying mixed-voltage system design.
SI86SS51EC-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:
- SPI
- Isolated Power:
- Yes
- Number of Channels:
- 5
- Inputs - Side 1/Side 2:
- 4/1
- Channel Type:
- Unidirectional
- Voltage - Isolation:
- 3750Vrms
- Common Mode Transient Immunity (Min):
- 150kV/µs
- Data Rate:
- 150Mbps
- Propagation Delay tpLH / tpHL (Max):
- 42ns, 42ns
- Pulse Width Distortion (Max):
- 2ns
- Rise / Fall Time (Typ):
- 2.5ns, 2.5ns
- Voltage - Supply:
- 2.25V ~ 5.5V
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Operating Temperature:
- -40°C ~ 125°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
SI86SS51EC-AS1R FAQ
1.How can I place an order for SI86SS51EC-AS1R through Aetrix?
Please submit a Request for Quotation (RFQ) for SI86SS51EC-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 SI86SS51EC-AS1R reliable?
The price and inventory of SI86SS51EC-AS1R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI86SS51EC-AS1R is usually 5 days.
3.What payment methods are accepted for SI86SS51EC-AS1R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI86SS51EC-AS1R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SI86SS51EC-AS1R?
SI86SS51EC-AS1R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SI86SS51EC-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 SI86SS51EC-AS1R?
For technical support, including SI86SS51EC-AS1R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI86SS51EC-AS1R requirements.
6.How does Aetrix verify that SI86SS51EC-AS1R is sourced from the original manufacturer or authorized distributors?
All SI86SS51EC-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 SI86SS51EC-AS1R meets industry standards.
7.What is the process for return or replacement of SI86SS51EC-AS1R?
All SI86SS51EC-AS1R units undergo pre-shipment inspection (PSI). If there is an issue with SI86SS51EC-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 SI86SS51EC-AS1R part is unused and in its original packaging.
Return procedure for SI86SS51EC-AS1R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SI86SS51EC-AS1R 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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