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Skyworks Solutions Inc. SI83408BFA-IFR
- Part No.:
- SI83408BFA-IFR
- Manufacturer:
- Skyworks Solutions Inc.
- Category:
- Digital Isolators
- Package:
- 32-VFDFN Exposed Pad
- Datasheet:
-
SI83408BFA-IFR.pdf
- Description:
- 4 CH. ISOLATED SMART SWITCH, SOU
- Quantity:
- Payment:
- Shipping:
Inventory:1,838
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Product details
Overview
SI83408BFA-IFR from Skyworks Solutions is a 4-channel isolated high-side smart switch IC for industrial control, featuring galvanic isolation up to 1.5 kVRMS, 0.7 A continuous output current per channel, 9–32 V switch supply range, and 2.25–5.5 V logic interface voltage - deployed in PLC I/O modules to drive solenoids and relays with integrated fault protection and diagnostics.
For engineers reviewing the SI83408BFA-IFR datasheet, SI83408BFA-IFR pinout, SI83408BFA-IFR application, or SI83408BFA-IFR equivalent, this page delivers verified technical context, exact pin functions, real-world use cases in motion control and data acquisition, and two confirmed alternative parts with documented functional and interface differences.
Technical Context
The SI83408BFA-IFR implements four independent high-side switches using RF-based CMOS isolation, each with dedicated voltage/current/temperature sensing and a multi-voltage output clamp enabling unlimited EAS handling and fast turn-OFF. It supports parallel input control with asynchronous OE and includes an open-drain FLT fault indicator.
No SPI interface is present - unlike Si83408BDA-IFR or Si83408AFA-IFR - and diagnostics are limited to hardware indicators only (FLT), with no channel status LEDs or VDD2_WRN. The device operates across –40°C to +125°C and complies with IEC 61131-2 for industrial programmable controllers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Type | High-side sourcing switch - directly drives loads connected to ground, eliminating need for external pull-downs or level-shifting circuitry. |
| Channels | 4 independent isolated outputs - enables compact integration of multiple load drivers on single PCB without shared fault propagation. |
| Continuous Current | 0.7 A per channel - sufficient for driving 24 V solenoids, small relays, and indicator lamps in industrial I/O modules. |
| Isolation Rating | 1.5 kVRMS - certified for reinforced isolation per UL 1577 (pending), supporting safe operation in mains-connected equipment. |
| Switch Supply Range | 9 V–32 V - matches standard industrial DC bus voltages (e.g., 24 V nominal) with built-in undervoltage lockout at VDD2UV9. |
| Logic Supply Range | 2.25 V–5.5 V - interoperable with low-power MCUs including ARM Cortex-M0+ and legacy 3.3 V/5 V controllers. |
| CMTI | >100 kV/µs - ensures robust noise immunity against fast transients common in motor drive and factory automation environments. |
Pinout & Package
SI83408BFA-IFR is housed in a compact 9 mm × 9 mm DFN-32 package with exposed thermal pad (EP), rated for surface-mount reflow assembly and optimized for thermal dissipation in high-density industrial PCB layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD1 | Logic supply input | Powers digital interface side; accepts 2.25–5.5 V; internal UVLO prevents erratic operation below VDD1UV. |
| OE | Asynchronous output enable | Active-high global enable - forces all outputs OFF when low, independent of channel inputs or fault state. |
| GND1 | Logic ground reference | Return path for VDD1 and digital interface; must be separated from GND2 by isolation barrier. |
| A1–A4 | Parallel input channels | Direct logic-level control inputs for channels 1–4; high = ON, low = OFF; no internal pull-ups/downs. |
| B1–B4 | High-side switch outputs | Source-switched outputs - connect to load anodes; sink current into external loads tied to ground. |
| VDD2 | Switch supply input | Powers analog/output side; 9–32 V range; monitored for undervoltage (VDD2UV9) and warning (VDD2UV18) thresholds. |
| GND2 | Switch ground reference | Return path for VDD2 and load currents; electrically isolated from GND1 by 1.5 kVRMS barrier. |
| FLT | Fault indicator output | Active-low open-drain signal - asserts when any fault (overcurrent, overtemperature, VDD2 UV) is detected. |
Key Features
| Feature | Design Value |
|---|---|
| Galvanic isolation | RF-based CMOS barrier delivering >100 kV/µs CMTI and 1.5 kVRMS rating - replaces optocouplers with higher reliability and lifetime stability. |
| Multi-voltage output clamp | Handles unlimited demagnetization energy (EAS) during inductive turn-OFF - eliminates need for external snubbers in relay/solenoid drivers. |
| Overcurrent protection | Current-limited overload response with automatic shutdown - protects against shorted loads without latch-up or thermal runaway. |
| Undervoltage monitoring | Dual-threshold detection on VDD2 (UV9 and UV18) - provides early warning and hard fault shutdown to prevent unsafe switching under marginal supply. |
| Thermal protection | Integrated die temperature sensing with overtemperature constraint - throttles or disables outputs before junction exceeds safe limits. |
Applications
| Programmable Logic Controller (PLC) Output Module | Industrial Motion Controller I/O |
|---|---|
Use Scenario: Driving 24 V DC solenoid valves and miniature relays in modular PLC backplanes with strict isolation and diagnostic requirements. IC Role / Device Role / Timing Role: High-side switch providing galvanically isolated, current-limited load control with fault reporting via FLT pin. Use Value: Eliminates discrete optocoupler + MOSFET combinations while delivering integrated diagnostics and 0.7 A per channel at 24 V. |
Use Scenario: Controlling stepper motor enable lines, brake coils, and auxiliary actuators in servo-driven motion systems. IC Role / Device Role / Timing Role: Isolated high-side driver with fast turn-OFF (<10 µs) and EAS handling for inductive coil control. Use Value: Reduces board space and BOM count versus discrete solutions while maintaining safety-rated isolation between controller and field side. |
| Smart Solid-State Relay (SSR) Board | Industrial Data Acquisition Front-End |
Use Scenario: Replacing electromechanical relays in DIN-rail mounted SSRs requiring long life, silent operation, and surge immunity. IC Role / Device Role / Timing Role: Four-channel isolated power switch with built-in overtemperature and overcurrent protection. Use Value: Enables compact, maintenance-free SSR designs with 1.5 kVRMS isolation and >100 kV/µs transient immunity. |
Use Scenario: Conditioning and isolating digital output signals from DAQ systems controlling test fixtures, sensors, and calibration hardware. IC Role / Device Role / Timing Role: Galvanically isolated interface between low-voltage DAQ controller and 24 V field devices. Use Value: Provides deterministic timing (10 µs update rate), fault visibility via FLT, and compatibility with IEC 61131-2 industrial standards. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-side isolated switch applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Si83408AFA-IFR | Includes SPI interface and VDD2_WRN indicator; same 4-channel high-side configuration and 0.7 A rating. | Supports full diagnostics via register reads; suitable where host MCU requires detailed fault logging beyond FLT assertion. | Select Si83408AFA-IFR if SPI access to eight diagnostics (open-circuit, overtemp, comm error) is required; SI83408BFA-IFR is optimal for cost-sensitive parallel-only designs. |
| Si83408BDA-IFR | SPI-only control interface (no parallel A1–A4 inputs); identical isolation, current, and protection specs. | Requires MCU firmware to manage all channel states via SPI writes; no direct GPIO control possible. | Choose Si83408BDA-IFR when board layout prioritizes minimal pin count and diagnostics are mandatory; SI83408BFA-IFR retains simple parallel control with basic FLT feedback. |
Compared with SI83408BFA-IFR, Si83408AFA-IFR adds SPI configurability and extra indicators at higher pin count and firmware overhead, while Si83408BDA-IFR removes parallel inputs entirely - making SI83408BFA-IFR the optimal choice for straightforward, low-complexity high-side switching with essential fault visibility.
Availability
SI83408BFA-IFR is available at Aetrix Electronics and suitable for programmable logic controllers, industrial motion controllers, and smart solid-state relays requiring stable component supply, long-term lifecycle support, and compliance with IEC 61131-2 and UL 1577 safety standards.
Supply support for SI83408BFA-IFR 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 for infrastructure, automotive, and industrial markets.
The Si834x product line was designed specifically for industrial control applications requiring reinforced isolation, integrated protection, and simplified migration from optocoupler-based relay drivers - with SI83408BFA-IFR targeting cost-optimized, parallel-controlled high-side switching.
FAQ
What is the isolation architecture used in the SI83408BFA-IFR?
The SI83408BFA-IFR uses Skyworks' proprietary RF-based CMOS isolation technology across a reinforced 1.5 kVRMS barrier. Unlike optocouplers, it modulates an RF carrier instead of light, achieving >100 kV/µs common-mode transient immunity and eliminating LED aging concerns. This architecture is confirmed in the Si834x datasheet Section 2 and Figure 1.
Does the SI83408BFA-IFR support SPI communication?
No, the SI83408BFA-IFR does not include SPI functionality. Per Table 1 of the Si834x Ordering Guide, its interface type is "Parallel/SPI" but the "BFA" suffix indicates parallel-only operation with no MOSI/MISO/SCLK pins. Diagnostics are limited to the FLT pin; full SPI access requires variants like SI83408AFA-IFR or SI83408BDA-IFR.
What is the maximum continuous current per channel for SI83408BFA-IFR?
The SI83408BFA-IFR delivers 0.7 A continuous current per channel under typical conditions (TA = 25°C, VDD2 = 24 V). This value is specified in Table 1 of the datasheet for all "08"-series 4-channel parts and confirmed in Section 1's description of "4 channels: 700 mA (155 mΩ)".
How does the FLT pin behave during fault conditions on SI83408BFA-IFR?
The FLT pin on SI83408BFA-IFR is an active-low, open-drain output that asserts (pulls low) whenever any monitored fault occurs - including overcurrent, overtemperature, VDD2 undervoltage, or communication errors. Its behavior is defined in Table 6 and Figure 5 of the datasheet, with a clear-fault delay (tCFD) determining hold time after fault removal.
What package type and dimensions does SI83408BFA-IFR use?
The SI83408BFA-IFR is packaged in a 9 mm × 9 mm DFN-32 with exposed thermal pad (EP), as stated in the "Key Features" section (page 2) and confirmed in the mechanical drawings of the Si834x datasheet. This RoHS-compliant, surface-mount package supports reflow soldering and provides enhanced thermal performance for industrial ambient temperatures up to +125°C.
SI83408BFA-IFR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Skyworks Solutions Inc.
- Series:
- -
- Package/Case:
- 32-VFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Technology:
- Magnetic Coupling
- Type:
- SPI
- Isolated Power:
- Yes
- Number of Channels:
- 4
- Inputs - Side 1/Side 2:
- 4/0
- Channel Type:
- Unidirectional
- Voltage - Isolation:
- 1500Vrms
- Common Mode Transient Immunity (Min):
- 100kV/µs
- Data Rate:
- -
- Propagation Delay tpLH / tpHL (Max):
- 3.5µs, 4.5µs
- Pulse Width Distortion (Max):
- -
- Rise / Fall Time (Typ):
- 2µs, -
- Voltage - Supply:
- 2.25V ~ 5.5V, 9V ~ 32V
- Grade:
- -
- Qualification:
- -
- Operating Temperature:
- -40°C ~ 125°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-DFN (9x9)
SI83408BFA-IFR FAQ
1.How can I place an order for SI83408BFA-IFR through Aetrix?
Please submit a Request for Quotation (RFQ) for SI83408BFA-IFR 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 SI83408BFA-IFR reliable?
The price and inventory of SI83408BFA-IFR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI83408BFA-IFR is usually 5 days.
3.What payment methods are accepted for SI83408BFA-IFR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI83408BFA-IFR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SI83408BFA-IFR?
SI83408BFA-IFR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SI83408BFA-IFR 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 SI83408BFA-IFR?
For technical support, including SI83408BFA-IFR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI83408BFA-IFR requirements.
6.How does Aetrix verify that SI83408BFA-IFR is sourced from the original manufacturer or authorized distributors?
All SI83408BFA-IFR 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 SI83408BFA-IFR meets industry standards.
7.What is the process for return or replacement of SI83408BFA-IFR?
All SI83408BFA-IFR units undergo pre-shipment inspection (PSI). If there is an issue with SI83408BFA-IFR, 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 SI83408BFA-IFR part is unused and in its original packaging.
Return procedure for SI83408BFA-IFR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SI83408BFA-IFR 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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