Skyworks Solutions Inc. SI8431AB-C-IS

Overview

SI8431AB-C-IS from Skyworks Solutions is a triple-channel digital isolator with reinforced insulation, rated for 2500 VRMS isolation, supporting up to 150 Mbps data rate and operating across –40 to 125 °C at 5 V or 3.3 V supply. It delivers worst-case propagation delay <9.5 ns, channel-to-channel skew ≤1.8 ns, and ultra-low power consumption (7.0 mA per side at 100 Mbps, 5 V). It is used in isolated motor control feedback loops requiring precise timing and high CMTI.

For engineers reviewing the SI8431AB-C-IS datasheet, SI8431AB-C-IS pinout, SI8431AB-C-IS application, or SI8431AB-C-IS equivalent, key selection criteria include its 150 Mbps capability, SOIC-16 wide-body package with 8.0 mm creepage/clearance, AEC-Q100 qualification, and compatibility with isolated ADC/DAC interfaces in industrial inverters.

Technical Context

The SI8431AB-C-IS implements capacitive isolation using on-chip RF modulation/demodulation across three independent channels, with separate primary-side (VDD1) and secondary-side (VDD2) supplies. Its architecture supports bidirectional signal transmission without start-up initialization and includes an enable input that places outputs in high-impedance state when asserted.

It features integrated 85 Ω output impedance per channel, 25 kV/µs common-mode transient immunity (CMTI), and operates stably under simultaneous 2.7–5.5 V supply conditions on both sides. Timing performance is guaranteed across temperature and voltage - including <6 ns typical propagation delay skew and 6 ns minimum pulse width at 150 Mbps.

Key Specifications

Pinout & Package

The SI8431AB-C-IS is housed in a 16-pin wide-body SOIC package (WB SOIC-16) with 8.0 mm minimum creepage and clearance, certified for reinforced insulation per IEC 60747-5-2 and UL 1577.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital isolator applications.

Compared with ADUM131BBRZ and ISO6731FDWR, the SI8431AB-C-IS uniquely combines 150 Mbps speed, 2500 VRMS rating in wide-body SOIC, and ≤1.8 ns channel skew - making it optimal for high-fidelity isolated feedback in automotive and industrial inverters where timing precision and noise immunity are co-critical.

Availability

SI8431AB-C-IS is available at Aetrix Electronics and suitable for industrial motor drives, EV onboard chargers, and isolated power supply monitoring requiring stable component supply and long-term lifecycle support.

Supply support for SI8431AB-C-IS 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 Si84xx family was designed for high-reliability galvanic isolation in harsh environments - targeting industrial automation, automotive electrification, and energy infrastructure where safety certification, timing accuracy, and thermal resilience are mandatory.

FAQ

What is the maximum data rate supported by the SI8431AB-C-IS?

The SI8431AB-C-IS supports a maximum data rate of 150 Mbps under specified conditions (VDD = 5 V, TA = –40 to 125 °C, CL = 15 pF). This is confirmed in Table 3 and Table 4 of the Skyworks datasheet Rev. 1.7 for the Si843xBx variant, which includes SI8431AB-C-IS. Performance remains stable across its full operating voltage and temperature range.

Does the SI8431AB-C-IS require external components for basic operation?

No, the SI8431AB-C-IS requires only two 0.1 µF bypass capacitors - one on VDD1 and one on VDD2 - as stated in the product description. No external resistors, transformers, or timing components are needed. The device powers up with valid data within 40 µs and needs no configuration or initialization sequence.

What safety certifications apply to the SI8431AB-C-IS?

The SI8431AB-C-IS is certified to UL 1577 (2500 VRMS, 1 min), CSA Component Notice 5A (IEC 60950-1/61010-1), and VDE IEC 60747-5-2. These are explicitly listed in Tables 6 and 7 of the datasheet. All certifications apply to the 2.5 kVRMS-rated devices, with production testing performed at 3.0 kVRMS for 1 second.

How does the enable (EN) pin function on the SI8431AB-C-IS?

The EN pin on the SI8431AB-C-IS is an active-high control that places all three outputs (OUT1–OUT3) into a high-impedance state when asserted. As shown in Figure 1 and Table 3, the enable-to-tri-state delay is ≤9.2 ns. When EN is low, normal signal transmission resumes with ≤8.0 ns enable-to-data-valid delay.

Is the SI8431AB-C-IS pin-compatible with other members of the Si843x family?

Yes, the SI8431AB-C-IS shares identical pinout and package (WB SOIC-16) with all Si8430/31/35 variants, including SI8430AB-C-IS and SI8435AB-C-IS. Pin assignments, supply connections, and enable functionality are fully consistent across the family, enabling drop-in replacement where speed and channel count align.