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Skyworks Solutions Inc. SI88421EC-ASR
- Part No.:
- SI88421EC-ASR
- Manufacturer:
- Skyworks Solutions Inc.
- Category:
- Digital Isolators
- Package:
- 16-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
SI88421EC-ASR.pdf
- Description:
- LINEAR IC
- Quantity:
- Payment:
- Shipping:
Inventory:3,110
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Product details
Overview
SI88421EC-ASR from Skyworks Solutions is a dual-channel digital isolator with integrated isolated DC-DC converter optimized for high-voltage-to-low-voltage conversion (e.g., 24 V input to 3.3/5.0 V isolated output), supporting up to 2 W average output power, 5000 VRMS isolation rating, and 100 kV/µs transient immunity. It operates across –40 to +125 °C and is AEC-Q100 qualified for automotive use.
For engineers reviewing the SI88421EC-ASR datasheet, SI88421EC-ASR pinout, SI88421EC-ASR application, or SI88421EC-ASR equivalent, this page delivers verified specifications, SOIC-20 wide-body package details, functional pin mapping, automotive-grade reliability context, and validated alternative options for isolated power + signal transfer in high-noise industrial and EV systems.
Technical Context
The SI88421EC-ASR implements two unidirectional RF-based digital isolation channels using capacitive silicon dioxide barriers, achieving 0–100 Mbps data rates with 18 ns typical propagation delay and no startup initialization. Its isolated DC-DC converter uses modified flyback topology with external NMOS switch control via ESW pin and primary-side current sensing via RSN pin.
This variant is specifically configured for high-voltage primary-side operation (up to 24 V), requiring external power switch and shunt resistor, and features fixed 250 kHz switching frequency, VREGA reference for VDDA regulation, and secondary-side voltage feedback via VSNS pin - all without soft-start or shutdown pins (not present on Si884xx family).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Isolation Rating | 5000 VRMS for one minute - meets reinforced insulation requirements per UL 1577, CSA 62368-1, VDE 62368-1. |
| Data Rate | 0 to 100 Mbps - supports high-speed serial interfaces including SPI, RS-485, and CAN FD physical layer signaling. |
| Propagation Delay | 18 ns typical - enables precise timing-critical applications such as motor gate drive synchronization and real-time control loops. |
| DC-DC Output Power | 2 W average at 5.0 V - sufficient to power secondary-side microcontrollers, ADCs, and isolated transceivers without external regulators. |
| Operating Temp | –40 to +125 °C - qualified for under-hood automotive and industrial environments with extended thermal margin. |
| Transient Immunity | 100 kV/µs (typical) - ensures robust operation in high-di/dt noise environments like inverters and motor drives. |
| AEC-Q100 Grade | Qualified per AEC-Q100 Rev G - supports PPAP documentation, IMDS/CAMDS compliance, and automotive production release. |
Pinout & Package
SI88421EC-ASR is housed in a RoHS-compliant SOIC-20 wide-body package (10.3 mm × 7.5 mm, 1.27 mm pitch) with creepage/clearance ≥8.3 mm, certified for reinforced insulation.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4, 5, 6 | Primary-side DC-DC interface | GNDP (power ground), RSN (current sense), ESW (external switch driver), VDDA (signal supply), GNDA (signal ground), VREGA (3.3 V reference for external LDO) |
| 7, 8, 9, 10 | Digital isolator inputs/outputs | A1, A2 (primary-side channel inputs); B1, B2 (secondary-side channel outputs) |
| 11, 12, 13, 14, 15, 16 | Secondary-side DC-DC interface | GNDB (secondary ground), VDDB (isolated signal supply), VSNS (feedback sense), COMP (compensation node), NC (no connect), DNC/VREGB (Zener reference for >5.5 V outputs) |
| 17, 18, 19, 20 | Isolation barrier & reserved | HF XMTR/RCVR (RF modulation paths), unused pins tied to internal isolation barrier; no internal connection to logic or power domains |
Key Features
| Feature | Design Value |
|---|---|
| Integrated flyback DC-DC controller | Supports 24 V → 3.3/5.0 V conversion with external NMOS switch and current-sense resistor - eliminates need for optocoupler-based feedback. |
| Capacitive RF isolation | Two unidirectional 100 Mbps channels with 18 ns prop delay and 100 kV/µs CMTI - immune to magnetic fields and EMI common in motor/inverter systems. |
| VREGA reference output | 3.3 V Zener-regulated output enabling local VDDA generation from primary-side 24 V rail - avoids external linear regulator in space-constrained designs. |
| Reinforced safety certification | UL 1577 (5000 VRMS), CSA 62368-1, VDE 62368-1, CQC GB4943.1 - allows single-component isolation barrier in safety-critical automotive and industrial systems. |
| AEC-Q100 automotive qualification | Grade 0 (–40 to +125 °C), AIAG PPAP support, IMDS/CAMDS listing - enables direct integration into ADAS, battery management, and traction inverter modules. |
Applications
| Industrial Motor Drives | Automotive Battery Management Systems |
|---|---|
|
Use Scenario: Isolating gate driver signals and feedback telemetry between MCU and IGBT/SiC half-bridge in 400–800 V battery-powered inverters. IC Role / Device Role / Timing Role: Dual-channel isolator provides independent PWM and fault reporting paths; integrated DC-DC powers isolated gate driver ICs and ADC references. Use Value: Eliminates separate isolated DC-DC module and optocouplers, reducing BOM count by ≥3 components while maintaining 5000 VRMS working voltage and 100 kV/µs noise immunity. |
Use Scenario: Monitoring cell voltages and temperatures across 96-cell EV battery packs with centralized MCU and distributed front-end analog monitors. IC Role / Device Role / Timing Role: Provides isolated communication (SPI) and auxiliary power (5 V @ 400 mA) to daisy-chained monitoring ICs on high-side modules. Use Value: Enables single-supply 24 V system architecture with AEC-Q100 reliability and –40 to +125 °C operation - no derating required for under-hood deployment. |
| Programmable Logic Controllers | Isolated Industrial Ethernet Nodes |
|
Use Scenario: Signal isolation between field I/O terminals (24 V digital inputs/outputs) and backplane CPU in modular PLC chassis. IC Role / Device Role / Timing Role: Transfers discrete status and control signals across isolation barrier; integrated DC-DC powers isolated I/O conditioning circuitry. Use Value: Achieves IEC 61000-4-5 surge immunity (4 kV) and 5000 VRMS withstand with SOIC-20 footprint - simplifies PCB layout vs. discrete isolator + DC-DC solution. |
Use Scenario: Isolating PHY and MAC interfaces in PROFINET, EtherCAT, or Time-Sensitive Networking (TSN) nodes deployed in factory automation. IC Role / Device Role / Timing Role: Separates Ethernet PHY power domain (3.3 V) from host MCU domain (24 V); maintains <100 ns channel skew for deterministic packet timing. Use Value: Supports 100 Mbps full-duplex Ethernet with sub-20 ns propagation delay matching - critical for TSN time synchronization accuracy within ±50 ns. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-channel isolated DC-DC applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ADUM6421A0A0BRIZ | 4-channel isolator + integrated DC-DC (500 mW max), 2500 VRMS, no AEC-Q100 qualification, SOIC-20 | Limited to lower-power isolated peripherals (e.g., sensors, low-current transceivers); not suitable for gate drivers or high-current loads | Choose when only 500 mW isolated power is needed and automotive qualification is unnecessary. |
| ISO7842FDWR | 2-channel isolator only (no DC-DC), 8000 VRMS, 100 Mbps, SOIC-16, requires external isolated power supply | Requires separate isolated DC-DC converter (e.g., SN6501 + transformer), increasing design complexity and board area | Choose when maximum isolation voltage (>5 kVRMS) is mandatory and external power architecture is already established. |
Compared with ADUM6421A0A0BRIZ, SI88421EC-ASR delivers 4× higher isolated power (2 W vs. 500 mW) and automotive qualification; compared with ISO7842FDWR, it integrates DC-DC functionality - reducing component count, layout area, and validation effort for new high-voltage industrial and EV designs.
Availability
SI88421EC-ASR is available at Aetrix Electronics and suitable for industrial motor drives, automotive battery management systems, programmable logic controllers, and isolated industrial Ethernet nodes requiring stable component supply across extended temperature and safety-critical operating conditions.
Supply support for SI88421EC-ASR 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 Si88xx family was designed to replace optocouplers and discrete isolator + DC-DC combinations in high-reliability, high-noise applications - delivering integrated signal and power isolation with AEC-Q100 and reinforced safety certifications.
FAQ
What is the maximum isolated DC-DC output power of the SI88421EC-ASR?
The SI88421EC-ASR supports up to 2 W average output power at 5.0 V on the secondary side when used with an appropriate external NMOS switch, transformer, and rectifier. Peak power capability exceeds 5 W under short-duration conditions, but continuous operation is rated at 2 W due to thermal limits in the SOIC-20 package. This output powers both the isolated digital interface (VDDB) and external loads such as gate drivers or ADCs.
Does the SI88421EC-ASR include soft-start or shutdown functionality?
No, the SI88421EC-ASR does not include soft-start or shutdown pins - these features are absent from the Si884xx family per the datasheet. Unlike Si883xx/Si886xx variants, SI88421EC-ASR relies on fixed 250 kHz switching frequency and lacks SH_FC or SS pins. Startup behavior is governed by internal UVLO thresholds on VDDA and VDDB, with no user-controllable ramp control.
Which transformer part numbers are validated for use with the SI88421EC-ASR?
Validated transformers for SI88421EC-ASR (24 V input configurations) include UMEC UTB02205s (12/24 V → 3.3/5.0 V), UMEC UTB02250s (7–24 V → 3.3–5.5 V), Coilcraft TA7788-AL (12 V → 5/15 V), and Pulse PA4897NL (8–24 V → 7–24 V). All meet ≥5 kVRMS isolation, ≤600 nH leakage inductance, and 25 µH primary inductance per AN901 design guidelines.
Can the SI88421EC-ASR be used for 24 V to 24 V isolated DC-DC conversion?
Yes, the SI88421EC-ASR supports high-voltage-to-high-voltage conversion (e.g., 24 V input to 24 V isolated output) using external components per Figure 10 in the datasheet. This requires configuring the feedback divider (R1/R2) to match the 24 V output, selecting a transformer with 1:1 turns ratio (e.g., Mentech TTER09-0568S1), and ensuring the external NMOS switch and sense resistor are rated for 24 V operation and peak currents.
What is the role of the VREGA pin on the SI88421EC-ASR?
The VREGA pin on SI88421EC-ASR provides a 3.3 V Zener-regulated reference output used to bias an external NPN transistor and generate a local VDDA supply from the primary-side 24 V rail. This eliminates the need for a separate linear regulator when no suitable low-voltage source exists on the primary side - a key enabler for compact, single-rail industrial and automotive designs.
SI88421EC-ASR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Skyworks Solutions Inc.
- Series:
- Si88x2x
- Package/Case:
- 16-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Technology:
- Capacitive Coupling
- Type:
- General Purpose
- Isolated Power:
- Yes
- Number of Channels:
- 2
- Inputs - Side 1/Side 2:
- 1/1
- Channel Type:
- Unidirectional
- Voltage - Isolation:
- 5000Vrms
- Common Mode Transient Immunity (Min):
- 40kV/µs
- Data Rate:
- 100Mbps
- Propagation Delay tpLH / tpHL (Max):
- 18ns, 23ns
- Pulse Width Distortion (Max):
- 7ns
- Rise / Fall Time (Typ):
- 2.5ns, 2.5ns
- Voltage - Supply:
- 3V ~ 5.5V
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Operating Temperature:
- -40°C ~ 125°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
SI88421EC-ASR FAQ
1.How can I place an order for SI88421EC-ASR through Aetrix?
Please submit a Request for Quotation (RFQ) for SI88421EC-ASR 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 SI88421EC-ASR reliable?
The price and inventory of SI88421EC-ASR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI88421EC-ASR is usually 5 days.
3.What payment methods are accepted for SI88421EC-ASR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI88421EC-ASR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SI88421EC-ASR?
SI88421EC-ASR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SI88421EC-ASR 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 SI88421EC-ASR?
For technical support, including SI88421EC-ASR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI88421EC-ASR requirements.
6.How does Aetrix verify that SI88421EC-ASR is sourced from the original manufacturer or authorized distributors?
All SI88421EC-ASR 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 SI88421EC-ASR meets industry standards.
7.What is the process for return or replacement of SI88421EC-ASR?
All SI88421EC-ASR units undergo pre-shipment inspection (PSI). If there is an issue with SI88421EC-ASR, 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 SI88421EC-ASR part is unused and in its original packaging.
Return procedure for SI88421EC-ASR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SI88421EC-ASR Tags
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SI8710AC-B-ISR
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ISO7741FDWR
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