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Home > Products > Isolators > Digital Isolators

Skyworks Solutions Inc. SI88444BD-ISR

Name: SI88444BD-ISR
Brand: Skyworks Solutions Inc.
SKU: SI88444BD-ISR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SI88444BD-ISR

Manufacturer:: Skyworks Solutions Inc.

Category:: Digital Isolators

Package:: 20-SOIC (0.295", 7.50mm Width)

Datasheet:: SI88444BD-ISR.pdf

Description:: IC DGTL ISO 5KV 4CH GP 20SOIC

Quantity:: RFQ Add To RFQ list

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Product details

Overview

SI88444BD-ISR from Skyworks Solutions is a quad-channel digital isolator with integrated isolated DC-DC converter, designed for high-voltage input (up to 24 V) to isolated 3.3/5.0 V or 24 V output configurations. It delivers up to 5 W peak isolated power, supports data rates up to 100 Mbps, achieves ≤23 ns propagation delay, and provides 5000 VRMS reinforced isolation. It is used in traction inverters and battery management systems where primary-side voltage exceeds 5.5 V and external FET drive is required.

For engineers reviewing the SI88444BD-ISR datasheet, SI88444BD-ISR pinout, SI88444BD-ISR application, or SI88444BD-ISR equivalent, this page delivers verified specifications, SOIC-20 wide-body package details, confirmed AEC-Q100 qualification, and validated alternative options for high-voltage isolated power + signal transfer in automotive and industrial systems.

Technical Context

The SI88444BD-ISR implements four unidirectional RF-based digital isolation channels across a silicon dioxide capacitive barrier, using on/off keying modulation for superior noise immunity and magnetic field rejection. Its isolated DC-DC converter uses a modified flyback topology with external primary-side NMOS switch (driven by ESW), current sensing via RSN, and secondary-side voltage feedback via VSNS.

This variant belongs to the Si884xx family optimized for high-voltage input operation (≥7 V up to 24 V). It features fixed 250 kHz switching frequency, no shutdown (SH) or soft-start (SS) pins, and requires Type 1 loop compensation at COMP with R_COMP = 100 kΩ. VREGA supports VDDA regulation when primary supply >5.5 V.

Key Specifications

Parameter	Value and Actual Design Meaning
Isolation Rating	5000 VRMS for 1 minute - meets UL 1577, CSA 62368-1, VDE 62368-1, and CQC GB4943.1 reinforced insulation requirements.
Data Rate	Up to 100 Mbps - enables high-speed serial communication (e.g., SPI, UART, CAN FD) across isolation barrier without timing bottlenecks.
Propagation Delay	≤23 ns max - ensures precise timing alignment in real-time control loops such as motor gate driving or ADC sampling synchronization.
DC-DC Output Power	Up to 5 W peak - sufficient to power secondary-side microcontrollers, sensors, and gate drivers in isolated domains without auxiliary supplies.
Operating Temp	–40 °C to +125 °C - qualified for under-hood automotive use and industrial environments with extended thermal cycling.
AEC-Q100 Grade	Qualified per AEC-Q100 Rev G - confirms robustness for automotive applications including HEV/EV traction inverters and BMS.
Package	SOIC-20 wide-body (7.5 mm body width) - provides 8.3 mm creepage/clearance, enabling compliance with reinforced insulation standards.

Pinout & Package

SI88444BD-ISR is housed in a RoHS-compliant SOIC-20 wide-body package (7.5 mm body width, 1.27 mm pitch), supporting 5000 VRMS isolation and ≥8.3 mm creepage/clearance. Pin numbering follows standard SOIC convention with isolation barrier separating primary (pins 1–10, 19–20) and secondary (pins 11–18) sides.

Pin/Terminal	Circuit Role	Design Meaning
1, 2, 3, 4, 5, 6, 9, 10	HF XMTR / HF RCVR (A1–A4, B1–B4)	Four unidirectional digital channel I/Os: A1–A4 on primary side, B1–B4 on secondary side - each pair crosses isolation barrier via RF modulation.
7, 8	RSN, ESW	Primary-side current sense input (RSN) and external NMOS switch driver output (ESW) - enables high-voltage flyback operation (>5.5 V input).
11, 12, 14, 13	GNDA, VDDA, VREGA, SH	Primary-side ground (GNDA), primary logic supply (VDDA ≤5.5 V), voltage reference for external regulator (VREGA), and unused SH pin (no shutdown function).
15, 16, 17, 18	GNDB, VDDB, DNC/VREGB, NC	Secondary-side ground (GNDB), secondary logic supply (VDDB), do-not-connect pin (DNC/VREGB - internal Zener active only if VOUT >5.5 V), and no-connect (NC).
19, 20	VSNS, COMP	Secondary-side feedback input (VSNS) and compensation node (COMP) - enables closed-loop regulation with R_COMP = 100 kΩ and external C_COMP.

Key Features

Feature	Design Value
RF-based digital isolation	On/off keying modulation provides 100 kV/µs typical transient immunity and immunity to magnetic fields - eliminates need for complex initialization or clock recovery.
Integrated flyback DC-DC controller	Supports 24 V primary input with external NMOS switch (ESW-driven) and current sensing (RSN) - enables efficient, compact isolated power without optocouplers or secondary-side biasing.
Secondary-side voltage sensing	VSNS feedback path transmits error signal across isolation barrier - achieves superior line/load regulation (<±1.5% over load/line) without optocoupler drift or aging.
Thermal protection & cycle skipping	Internal thermal shutdown prevents junction damage; automatic cycle skipping at light loads reduces switching losses - improves efficiency across full load range.
AEC-Q100 automotive qualification	Validated for automotive-grade reliability including HTOL, TC, UHAST, and ESD - supports PPAP documentation and IMDS/CAMDS compliance for Tier-1 supply chains.

Applications

Traction Inverter Control	Battery Management System (BMS)
Use Scenario: Isolating gate-drive signals and analog feedback from high-voltage DC bus (400–800 V) to MCU in EV traction inverters. IC Role / Device Role / Timing Role: SI88444BD-ISR provides four isolated digital channels for PWM gate control (A1–A4 → B1–B4) and isolated 5 V power (via DC-DC) for secondary-side gate drivers and current sensors. Use Value: Enables single-chip isolation + power solution replacing discrete optocouplers + isolated DC-DC modules - reduces PCB area by >40% and eliminates optocoupler aging-related timing drift.	Use Scenario: Monitoring cell voltages and temperatures across 96-cell series stack in high-voltage EV battery packs. IC Role / Device Role / Timing Role: SI88444BD-ISR isolates SPI communication between primary-side MCU and secondary-side analog front-end (AFE) ICs while powering them via its integrated DC-DC output. Use Value: Delivers precise, low-jitter timing (≤23 ns prop delay) for synchronized multi-channel ADC sampling - critical for accurate state-of-charge (SoC) calculation.
Industrial PLC Analog I/O Module	Isolated Switch-Mode Power Supply (SMPS)
Use Scenario: Providing galvanic isolation between field-side 24 V sensor inputs and controller-side 3.3 V logic in programmable logic controllers. IC Role / Device Role / Timing Role: SI88444BD-ISR isolates digital status/control lines (e.g., fault flags, enable signals) and powers isolated ADC/DAC interfaces using its regulated 5 V output. Use Value: Eliminates need for separate isolated DC-DC converter - simplifies BOM and improves long-term reliability versus transformer-based solutions with aging magnetics.	Use Scenario: Generating isolated 5 V or 24 V auxiliary supply in telecom rectifiers or server PSUs with 24–48 V input rails. IC Role / Device Role / Timing Role: SI88444BD-ISR functions as isolated flyback controller with external MOSFET (driven by ESW), current sense (RSN), and secondary-side feedback (VSNS). Use Value: Achieves 83% peak efficiency with external power switch - outperforms opto-coupled feedback designs by >8% efficiency and reduces thermal design complexity.

Traction Inverter Control

Battery Management System (BMS)

Use Scenario: Isolating gate-drive signals and analog feedback from high-voltage DC bus (400–800 V) to MCU in EV traction inverters.

IC Role / Device Role / Timing Role: SI88444BD-ISR provides four isolated digital channels for PWM gate control (A1–A4 → B1–B4) and isolated 5 V power (via DC-DC) for secondary-side gate drivers and current sensors.

Use Value: Enables single-chip isolation + power solution replacing discrete optocouplers + isolated DC-DC modules - reduces PCB area by >40% and eliminates optocoupler aging-related timing drift.

Use Scenario: Monitoring cell voltages and temperatures across 96-cell series stack in high-voltage EV battery packs.

IC Role / Device Role / Timing Role: SI88444BD-ISR isolates SPI communication between primary-side MCU and secondary-side analog front-end (AFE) ICs while powering them via its integrated DC-DC output.

Use Value: Delivers precise, low-jitter timing (≤23 ns prop delay) for synchronized multi-channel ADC sampling - critical for accurate state-of-charge (SoC) calculation.

Industrial PLC Analog I/O Module

Isolated Switch-Mode Power Supply (SMPS)

Use Scenario: Providing galvanic isolation between field-side 24 V sensor inputs and controller-side 3.3 V logic in programmable logic controllers.

IC Role / Device Role / Timing Role: SI88444BD-ISR isolates digital status/control lines (e.g., fault flags, enable signals) and powers isolated ADC/DAC interfaces using its regulated 5 V output.

Use Value: Eliminates need for separate isolated DC-DC converter - simplifies BOM and improves long-term reliability versus transformer-based solutions with aging magnetics.

Use Scenario: Generating isolated 5 V or 24 V auxiliary supply in telecom rectifiers or server PSUs with 24–48 V input rails.

IC Role / Device Role / Timing Role: SI88444BD-ISR functions as isolated flyback controller with external MOSFET (driven by ESW), current sense (RSN), and secondary-side feedback (VSNS).

Use Value: Achieves 83% peak efficiency with external power switch - outperforms opto-coupled feedback designs by >8% efficiency and reduces thermal design complexity.

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
SI88440BD-ISR	No internal VREGA; requires external linear regulator for VDDA if primary supply >5.5 V. Same SOIC-20 package and pinout.	Lacks integrated VREGA reference - unsuitable when primary-side supply exceeds 5.5 V and no local LDO is available.	Select SI88440BD-ISR only when VDDA can be sourced locally ≤5.5 V; otherwise SI88444BD-ISR's VREGA enables direct high-voltage primary-side regulation.
ADUM6420ARWZ	Analog Devices part with 4-channel isolator + 500 mW isolated DC-DC (not 5 W); uses different transformer interface and lacks RSN/ESW pins.	Lower power output limits use to low-power MCU/sensor domains; not suitable for gate-driver power or high-current loads.	Choose ADUM6420ARWZ for space-constrained, low-power applications needing only ~500 mW; SI88444BD-ISR is required for >2 W secondary-side loads.

Compared with SI88440BD-ISR, SI88444BD-ISR adds VREGA for direct high-voltage primary-side regulation, eliminating an external LDO. Against ADUM6420ARWZ, it delivers 10× more isolated power (5 W vs. 500 mW) and supports external FET drive for higher-efficiency flyback topologies - making it uniquely suited for automotive traction and industrial power conversion.

Availability

SI88444BD-ISR is available at Aetrix Electronics and suitable for traction inverters, battery management systems, and isolated switch-mode power supplies requiring stable component supply, automotive-grade reliability, and integrated high-power isolation.

Supply support for SI88444BD-ISR 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 product line was engineered to replace optocouplers and discrete isolated DC-DC modules in automotive and industrial systems - delivering integrated signal + power isolation with AEC-Q100 qualification and reinforced safety certification.

FAQ

What is the maximum isolated output power of the SI88444BD-ISR?

The SI88444BD-ISR supports up to 5 W peak isolated output power when used with an appropriately rated external transformer and NMOS switch. This capability is enabled by its ESW pin (external switch driver) and RSN pin (current sense), allowing efficient high-voltage flyback operation - significantly exceeding the 500 mW limit of optocoupler-integrated alternatives like ADUM6420ARWZ.

Does the SI88444BD-ISR support shutdown or soft-start functionality?

No, the SI88444BD-ISR does not include shutdown (SH) or soft-start (SS) functionality. As confirmed in Section 2.3.1 of the datasheet, these features are unavailable on Si884xx devices. Pin 6 is labeled "SH" but is unused; the device relies on fixed 250 kHz operation and inherent thermal protection instead of user-controlled startup sequencing.

What transformer specifications are validated for use with the SI88444BD-ISR?

Validated transformers for SI88444BD-ISR include UMEC UTB02250s (7–24 V input, 3.3–5.5 V output, 3.0:1 turns ratio, 5 kVRMS isolation) and Mentech TTER09-0458S1 (8–24 V input/output, 1.0:1 ratio, 5 kVRMS). These meet leakage inductance (<600 nH), primary inductance (25 µH ±5%), and isolation rating requirements specified in AN901 for high-voltage Si884xx operation.

How is loop compensation implemented on the SI88444BD-ISR?

Loop compensation for the SI88444BD-ISR's DC-DC converter is implemented externally at the COMP pin using a Type 1 network: a 100 kΩ resistor (RCOMP) in series with a capacitor (CCOMP). The capacitance value is calculated based on target crossover frequency (fC) using C_COMP = 1/(2π × fC × R_COMP). This differs from Si882xx/3xx variants, which use 49.9 kΩ.

Can the SI88444BD-ISR be used for 24 V to 24 V isolated conversion?

Yes, the SI88444BD-ISR supports 24 V to 24 V isolated DC-DC conversion. As stated in Section 2.3.13, Si884xx devices are intended for high-voltage configurations including 24 V input to 24 V output. This requires an external transformer (e.g., Mentech TTER09-0458S1), NMOS switch driven by ESW, and appropriate resistor divider on VSNS to set output voltage.

SI88444BD-ISR Specifications

Product attributes: Attribute value

Manufacturer:: Skyworks Solutions Inc.

Series:: -

Package/Case:: 20-SOIC (0.295", 7.50mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Not For New Designs

Technology:: Capacitive Coupling

Type:: General Purpose

Isolated Power:: No

Number of Channels:: 4

Inputs - Side 1/Side 2:: 0/4

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:: -

Qualification:: -

Operating Temperature:: -40°C ~ 125°C

Mounting Type:: Surface Mount

Supplier Device Package:: 20-SOIC

SI88444BD-ISR FAQ

1.How can I place an order for SI88444BD-ISR through Aetrix?

Please submit a Request for Quotation (RFQ) for SI88444BD-ISR 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 SI88444BD-ISR reliable?

The price and inventory of SI88444BD-ISR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI88444BD-ISR is usually 5 days.

3.What payment methods are accepted for SI88444BD-ISR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI88444BD-ISR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SI88444BD-ISR?

SI88444BD-ISR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SI88444BD-ISR 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 SI88444BD-ISR?

For technical support, including SI88444BD-ISR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI88444BD-ISR requirements.

6.How does Aetrix verify that SI88444BD-ISR is sourced from the original manufacturer or authorized distributors?

All SI88444BD-ISR 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 SI88444BD-ISR meets industry standards.

7.What is the process for return or replacement of SI88444BD-ISR?

All SI88444BD-ISR units undergo pre-shipment inspection (PSI). If there is an issue with SI88444BD-ISR, 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 SI88444BD-ISR part is unused and in its original packaging.

Return procedure for SI88444BD-ISR:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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