Skyworks Solutions Inc. SI8640EB-AU

Overview

SI8640EB-AU from Skyworks is a quad-channel, unidirectional digital isolator with 4 inputs on VDD1 side and 0 inputs on VDD2 side, delivering 150 Mbps data rate, <10 ns propagation delay, and 2.5 kV RMS isolation rating in QSOP-16 package. It features Schmitt-trigger inputs, tri-state outputs with single enable control (EN), and selectable high-default fail-safe mode - deployed in battery management systems and isolated ADC interfaces where signal integrity and power-loss behavior are critical.

For engineers reviewing the SI8640EB-AU datasheet, SI8640EB-AU pinout, SI8640EB-AU application, or SI8640EB-AU equivalent, key selection criteria include its 4-channel input-only topology, automotive-grade AEC-Q100 qualification, 2.5–5.5 V dual-supply operation, and reinforced insulation compliance per VDE 0884-10 for safety-critical subsystems.

Technical Context

The SI8640EB-AU implements RF-based on/off keying across a silicon-die isolation barrier, eliminating startup initialization and enabling deterministic timing without PLL lock time. Its architecture supports independent undervoltage lockout (UVLO) on both sides, with VDDUV+ = 2.24 V (typ) and hysteresis of 70 mV (typ), ensuring robust operation during brownout conditions.

All four channels reside on the input side (Side A), driving outputs on Side B; EN is located on Side B and controls all four outputs simultaneously. The device uses Schmitt-trigger inputs (VT+ = 1.67 V, VT– = 1.23 V, VHYS = 0.44 V typ) for >50 kV/µs common-mode transient immunity and operates across –40 to +125 °C ambient temperature.

Key Specifications

Pinout & Package

SI8640EB-AU is housed in a 16-pin QSOP package with 1.27 mm lead pitch and 0.150" body width. Pin numbering follows standard QSOP convention (pin 1 marked, counterclockwise).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADUM140E0BRQZ and ISO7740FDWR, SI8640EB-AU uniquely combines AEC-Q100 qualification, high-default fail-safe mode, and QSOP-16 footprint - making it optimal for space-constrained automotive BMS modules requiring guaranteed safe-state behavior during supply faults.

Availability

SI8640EB-AU is available at Aetrix Electronics and suitable for battery management systems, on-board chargers, traction inverters, and isolated ADC interfaces requiring stable component supply across automotive and industrial production programs.

Supply support for SI8640EB-AU 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 infrastructure, automotive, and industrial markets.

The Si864x family was engineered specifically for high-reliability, high-speed digital isolation in automotive electrification and industrial power systems - emphasizing AEC-Q100 compliance, low-power operation, and robust noise immunity across extended temperature ranges.

FAQ

What is the isolation rating and safety certification status of SI8640EB-AU?

SI8640EB-AU provides 2.5 kV RMS isolation and is certified to UL 1577 (1 min), CSA Component Notice 5A, and basic VDE 0884-10. It meets IEC 62368-1 and IEC 60601-1 requirements for reinforced insulation in medical and industrial equipment. As an automotive-grade part, it carries full AEC-Q100 Grade 1 qualification and is supported with AIAG-compliant PPAP documentation.

Does SI8640EB-AU require external pull-up or pull-down resistors on its inputs or outputs?

No. SI8640EB-AU integrates internal 2 µA pull-ups on inputs/outputs for high-default variants like SI8640EB-AU, eliminating need for external biasing. Its Schmitt-trigger inputs (VT+ = 1.67 V, VT– = 1.23 V) provide inherent noise immunity, and outputs drive 4 mA at VOH/VOL specifications without external termination under standard loads.

How does the EN pin function on SI8640EB-AU, and what happens to outputs when EN is low?

EN is a single active-high enable input on the output side (VDD2 domain). When EN = low, all four outputs (OUTB1–OUTB4) enter high-impedance state within 12 ns (ten2 max), decoupling downstream circuitry. This feature enables system-level power sequencing and hot-swap capability without affecting input-side operation.

What is the maximum ambient operating temperature for SI8640EB-AU, and how does temperature affect propagation delay?

SI8640EB-AU operates from –40 to +125 °C ambient temperature. Propagation delay varies from 5.0 ns (min) to 13 ns (max) across this range, with typical value of 8.0 ns at 25 °C and 5 V supply. Temperature-induced delay variation is monotonic and fully characterized per Table 4.2 - enabling accurate timing budgeting in automotive powertrain applications.

Can SI8640EB-AU interface directly with 3.3 V microcontrollers and 5 V analog circuits?

Yes. SI8640EB-AU supports independent 2.5–5.5 V supplies on both sides: VDD1 can be 3.3 V for MCU-side logic compatibility, while VDD2 can be 5 V to drive analog ICs or level-shifted interfaces. Input thresholds (VIH = 2.0 V min, VIL = 0.8 V max) and output drive strength (VOH ≥ VDD2 – 0.4 V) ensure robust interoperability across mixed-voltage domains without external level shifters.