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Skyworks Solutions Inc. SI88644EC-ASR
- Part No.:
- SI88644EC-ASR
- Manufacturer:
- Skyworks Solutions Inc.
- Category:
- Digital Isolators
- Package:
- 24-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
SI88644EC-ASR.pdf
- Description:
- LINEAR IC
- Quantity:
- Payment:
- Shipping:
Inventory:2,252
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Product details
Overview
SI88644EC-ASR from Skyworks Solutions is a quad-channel digital isolator with integrated isolated DC-DC converter, delivering up to 5 W peak output power, supporting 100 Mbps data rate, 23 ns max propagation delay, and 5000 VRMS isolation. It operates across –40 to +125 °C and targets high-reliability industrial and automotive power conversion and signal isolation.
For engineers reviewing the SI88644EC-ASR datasheet, SI88644EC-ASR pinout, SI88644EC-ASR application, or SI88644EC-ASR equivalent, this page provides verified functional specifications, SOIC-24 wide-body package mapping, transformer-coupled flyback DC-DC architecture details, and validated alternative options for 24 V input to isolated 5 V/24 V output systems.
Technical Context
The SI88644EC-ASR implements four unidirectional RF-based digital isolation channels using capacitive silicon dioxide barriers, with on/off keying modulation for superior EMI immunity and 18 ns typical propagation delay. Its isolated DC-DC converter uses external NMOS switching (via ESW pin) and current sensing (RSN pin) in a peak-current-mode flyback topology.
This variant is configured for high-voltage primary-side operation (up to 24 V input), requiring external power switch Q1 and sense resistor R4. It supports programmable switching frequency (200–800 kHz via SH_FC/SS RC network) and soft-start control (capacitor on SS), with secondary-side voltage feedback via VSNS and loop compensation at COMP.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Isolation Rating | 5000 VRMS for one minute - enables reinforced insulation per UL 1577, CSA 62368-1, and VDE 62368-1. |
| Data Rate | Up to 100 Mbps - supports high-speed serial interfaces including SPI, RS-485, and CAN FD physical layer signaling. |
| Propagation Delay | 23 ns maximum - ensures tight timing alignment in real-time control loops and motor gate driver feedback paths. |
| DC-DC Output Power | Up to 5 W peak with external FET - sufficient to power isolated microcontrollers, ADCs, and gate drivers without auxiliary supplies. |
| Operating Temp | –40 to +125 °C - qualified for under-hood automotive and industrial ambient environments. |
| Transient Immunity | 100 kV/µs typical - maintains signal integrity during fast-switching events in inverters and SMPS. |
| AEC-Q100 Grade | Qualified - meets automotive reliability requirements for hybrid/electric vehicle battery management and traction inverters. |
Pinout & Package
SI88644EC-ASR is housed in a RoHS-compliant SOIC-24 wide-body package (15.4 mm × 7.5 mm, 1.27 mm pitch) with creepage/clearance optimized for 5000 VRMS isolation. Pin layout follows Figure 4 (Si88644) in the datasheet.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDDA | Digital isolator primary-side supply | Accepts 3.0–5.5 V; powers A-side logic and internal controller; requires local bypass capacitor. |
| GNDA | Primary-side signal ground | Must be short-traced to GNDP; forms low-inductance return path for isolator and DC-DC control circuitry. |
| A1–A4 | Primary-side digital input channels | Unidirectional inputs; compatible with CMOS logic levels; no external bias required. |
| VDDP | DC-DC primary-side power input | Accepts up to 24 V input; connects to external bulk capacitor and transformer primary winding. |
| GNDP | DC-DC primary-side ground | Shared reference for VDDP, ESW, RSN, and SH_FC; must be directly tied to GNDA with minimal trace length. |
| ESW | External switch driver output | Drives gate of external NMOS Q1; enables high-voltage (>5.5 V) primary-side operation. |
| RSN | Current sense input | Monitors peak primary current via shunt resistor R4; sets overcurrent protection threshold. |
| SH_FC | Shutdown and frequency control | High-level assertion disables DC-DC; RC network with SS sets PWM frequency between 200–800 kHz. |
| SS | Soft-start timing capacitor | Controls inrush current limiting during startup; capacitor value determines ramp time for VDDB rise. |
| VREGA | Primary-side voltage reference | Internal Zener output; used with external NPN transistor to generate regulated VDDA when input >5.5 V. |
| VDDB | Digital isolator secondary-side supply | Output of isolated DC-DC; powers B-side logic; adjustable from 3.3 V to 24 V via R1/R2 divider. |
| GNDB | Secondary-side signal ground | Reference for VDDB and B1–B4; isolated from GNDA; connects to COMP and VSNS return. |
| B1–B4 | Secondary-side digital output channels | Unidirectional outputs; rail-to-rail swing; drive loads up to 10 mA per channel. |
| VSNS | DC-DC output voltage feedback | Connects to resistor divider across VDDB; enables precise regulation independent of load or line variation. |
| COMP | Loop compensation node | Receives external RC network (RCOMP = 100 kΩ, CCOMP calculated per crossover frequency) for stable flyback control. |
| DNC/VREGB | Secondary-side voltage reference or no-connect | Internally zenered; connect only if VDDB >5.5 V; otherwise leave floating or NC per datasheet guidance. |
Key Features
| Feature | Design Value |
|---|---|
| Flyback DC-DC with external FET control | Enables 24 V input operation while maintaining high efficiency (83% peak) and thermal safety via cycle skipping at light loads. |
| Secondary-side voltage sensing | Eliminates optocouplers and associated bias circuitry, improving long-term reliability and load regulation accuracy (±1.5% typical). |
| Programmable soft start & shutdown | Capacitor-controlled SS pin limits inrush current; SH_FC pin allows system-level enable/disable without power cycling. |
| RF-based isolation architecture | Capacitive SiO₂ barrier with on/off keying delivers 100 kV/µs transient immunity and immunity to magnetic field coupling. |
| AEC-Q100 qualification | Validated for automotive use including battery management systems and traction inverter gate drive isolation. |
| SOIC-24 wide-body packaging | Provides 8.3 mm creepage and clearance, meeting reinforced insulation requirements for 5000 VRMS test voltage. |
Applications
| Industrial Motor Control | Automotive Battery Management |
|---|---|
Use Scenario: Isolating gate drive signals and current-sense feedback in 3-phase IGBT/SiC inverter stages. IC Role / Device Role / Timing Role: Provides galvanically isolated 4-channel signal transmission and localized 5 V/24 V isolated power for gate drivers and ADCs. Use Value: Enables compact, single-package solution replacing discrete isolators + isolated DC-DC modules, reducing BOM count by ≥3 components. |
Use Scenario: Monitoring cell voltages and temperature sensors across high-voltage battery packs (up to 900 V). IC Role / Device Role / Timing Role: Delivers reinforced isolation for analog front-end digitization and MCU communication across multiple pack modules. Use Value: Meets ASIL-D functional safety requirements via certified 5000 VRMS barrier and AEC-Q100 Grade 0 qualification. |
| Traction Inverter Interface | Isolated Switch-Mode Power Supply |
Use Scenario: Transmitting PWM commands from MCU to isolated gate driver ICs in EV traction inverters. IC Role / Device Role / Timing Role: Transmits high-speed, low-jitter control signals (≤23 ns delay) while powering secondary-side drivers from 24 V bus. Use Value: Supports 100 Mbps operation for high-resolution PWM and fault reporting, eliminating timing skew vs. optocoupler-based solutions. |
Use Scenario: Providing isolated auxiliary power and signal isolation in telecom rectifiers and server PSUs. IC Role / Device Role / Timing Role: Replaces separate isolated DC-DC converter and digital isolator pair in 48 V input systems. Use Value: Reduces footprint by 40% vs. dual-component solution; achieves 83% peak efficiency with external FET and Schottky diode. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad-channel isolated DC-DC applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SI88642EC-ASR | Same SOIC-24 package and pinout; differs in default failsafe state (A1–A4 default high vs. low on SI88644EC-ASR). | Used where default-output-high behavior is required during power-up or fault conditions. | Select SI88642EC-ASR when system logic expects active-high default on isolated outputs during reset. |
| ADUM6421ARWZ | 4-channel isolator + 500 mW isolated DC-DC; lower output power, fixed 3.3 V output, no programmable frequency or soft start. | Suitable for low-power MCU interfaces but not for driving gate drivers or high-current loads. | Choose ADUM6421ARWZ only for ≤500 mW secondary-side loads and non-automotive applications lacking AEC-Q100 need. |
Compared with SI88644EC-ASR, SI88642EC-ASR offers identical power and isolation specs but inverted failsafe logic, while ADUM6421ARWZ trades 10× less output power and no programmability for simpler implementation in low-power signal-only roles.
Availability
SI88644EC-ASR is available at Aetrix Electronics and suitable for industrial motor control, automotive battery management, and isolated switch-mode power supply designs requiring stable component supply, long-lifecycle support, and AEC-Q100 compliance.
Supply support for SI88644EC-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.
The Si88x4x family was designed to replace optocoupler-based isolation and discrete DC-DC converters in high-reliability industrial and automotive systems demanding integrated signal + power isolation.
FAQ
What is the maximum input voltage supported by SI88644EC-ASR?
The SI88644EC-ASR supports up to 24 V DC on its VDDP pin. It is specifically designed for high-voltage primary-side operation using an external NMOS switch driven by the ESW pin and current sensing via the RSN pin. This configuration enables robust performance in automotive 12 V/24 V and industrial 24 V bus applications without internal switch limitations.
Does SI88644EC-ASR require an external transformer?
Yes, SI88644EC-ASR requires an external miniature transformer (e.g., UMEC UTB02250s or Coilcraft TA7788-AL) to implement its isolated flyback DC-DC converter. The transformer provides galvanic isolation for both power transfer and feedback, and its turns ratio and leakage inductance are critical to achieving specified output regulation and efficiency. Layout guidelines mandate short, low-inductance traces to transformer pins.
How is the isolated output voltage set on SI88644EC-ASR?
The isolated output voltage (VDDB) is set by an external resistor divider (R1/R2) connected between VDDB and GNDB, feeding the VSNS pin. The internal error amplifier compares the divided voltage to a 1.22 V reference, adjusting duty cycle to maintain regulation. For example, using R1 = 100 kΩ and R2 = 15.4 kΩ yields ~5.0 V output. Full calculation is provided in the datasheet Equation on page 9.
What is the purpose of the COMP pin on SI88644EC-ASR?
The COMP pin on SI88644EC-ASR is the compensation node for the DC-DC converter's peak-current-mode control loop. It requires an external RC network (RCOMP = 100 kΩ, CCOMP calculated per target crossover frequency) to stabilize regulation against load and line transients. Incorrect compensation can cause oscillation or poor transient response, especially under dynamic load steps common in motor control.
Is SI88644EC-ASR pin-compatible with other Si88x4x variants?
SI88644EC-ASR is pin-compatible with all Si886xx variants (e.g., SI88640–SI88643) in the SOIC-24 package, sharing identical pin functions and layout. However, it is not pin-compatible with Si882xx, Si883xx, or Si884xx families due to differing pin assignments (e.g., SH vs. SH_FC location, presence of RSN/ESW). Always verify pin mapping against Figure 4 in the datasheet before PCB design.
SI88644EC-ASR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Skyworks Solutions Inc.
- Series:
- Si88x4x
- Package/Case:
- 24-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:
- 4
- Inputs - Side 1/Side 2:
- 0/4
- Channel Type:
- Unidirectional
- Voltage - Isolation:
- 3750Vrms
- 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:
- 24-SOIC
SI88644EC-ASR FAQ
1.How can I place an order for SI88644EC-ASR through Aetrix?
Please submit a Request for Quotation (RFQ) for SI88644EC-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 SI88644EC-ASR reliable?
The price and inventory of SI88644EC-ASR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI88644EC-ASR is usually 5 days.
3.What payment methods are accepted for SI88644EC-ASR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI88644EC-ASR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SI88644EC-ASR?
SI88644EC-ASR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SI88644EC-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 SI88644EC-ASR?
For technical support, including SI88644EC-ASR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI88644EC-ASR requirements.
6.How does Aetrix verify that SI88644EC-ASR is sourced from the original manufacturer or authorized distributors?
All SI88644EC-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 SI88644EC-ASR meets industry standards.
7.What is the process for return or replacement of SI88644EC-ASR?
All SI88644EC-ASR units undergo pre-shipment inspection (PSI). If there is an issue with SI88644EC-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 SI88644EC-ASR part is unused and in its original packaging.
Return procedure for SI88644EC-ASR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SI88644EC-ASR Tags
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ISO1212DBQR
Texas Instruments
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ISO6721BDR
Texas Instruments
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SI8710AC-B-ISR
Skyworks Solutions Inc.
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ISO7720FDR
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ISO7721DR
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ISO7721FDR
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SI8710CC-B-ISR
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ISO6741FQDWRQ1
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ISO7721DWVR
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ISO7762FDBQR
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ISO7741DWR
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ISO7741FDWR
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