SI8642BB-B-IU - 4-Ch 2.5kV Digital Isolator, 150Mbps | Skyworks
MPN: SI8642BB-B-IU ✓ Hoạt độngSI8642BB-B-IU Tóm tắt
A digital isolator is a semiconductor device that transmits data or clock signals across an isolation barrier using high-voltage capacitors (capacitive coupling) or transformers (inductive coupling) instead of optocouplers. The quad-channel digital isolator family (digital isolator -> capacitive isolator -> signal isolator -> interface IC -> semiconductor) replaces legacy optocouplers in modern designs, providing faster data rates, lower power consumption, tighter channel-to-channel matching, and integration of multiple channels in one package — advantages that translate to smaller PCB area, predictable propagation delays, and higher CMTI for noisy motor drive or inverter environments.
Key specifications include a propagation delay below 10 ns (typical 8 ns per the datasheet), 2.375 V to 5.5 V supply range on both sides, low quiescent current, and DC-correct output behavior so input idle states are mirrored without DC biasing. The device supports fail-safe output states and a per-channel enable control on selected variants. The narrow-body 16-QSOP package keeps creepage and clearance within 2.5 kVrms reinforced-insulation ratings per UL 1577 while saving board space versus SOIC-16 wide-body isolators.
The architecture uses Skyworks' proprietary CMOS-based capacitive isolation technology, integrating four isolation channels in a single die with deterministic timing and high CMTI. This capacitive approach avoids the aging, current-transfer-ratio degradation, and slow switching inherent to optocouplers, while consuming far less power and supporting multi-Mbps signaling. Each channel transmits logic transitions via high-voltage capacitors embedded in the die, with on-chip decoding restoring clean logic levels at the output.
Typical applications include isolated SPI/UART interfaces in PLCs, isolated gate-drive signal interfaces in motor-control power stages, isolated serial communication links in solar inverters, isolated digital I/O modules in industrial automation, and isolated data-acquisition channels in medical and energy-metering systems. The wide 2.375 V – 5.5 V supply range makes the device compatible with both 3.3 V microcontrollers and legacy 5 V logic.
When using the SI8642BB-B-IU, observe the PCB layout recommendations in the datasheet for creepage and clearance to maintain 2.5 kVrms rating: place the device so its body spans the high-voltage isolation barrier, and avoid copper traces and vias under the QSOP package between input and output ground islands. Decouple each VDD pin with a 0.1 µF low-ESL ceramic capacitor placed within 2 mm of the pin.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Bộ thay thế dễ dàng lắp đặt cho SI8642BB-B-IU — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với SI8642BB-B-IU (cùng hình factor và footprint) — khác nhau ở Package, Common-Mode Transient Immunity (CMTI), Channel Configuration, Number of Channels, Operating Temperature Range.
SI8641BB-B-IU
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →SI8640BB-B-IU
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
SI8642BB-B-IUR
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
ADUM1411ARWZ
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →SI8642BB-B-IU Thông số kỹ thuật
| Type | Digital Isolator, General Purpose |
| Number of Channels | 4 |
| Channel Configuration | 2 forward / 2 reverse |
| Isolation Voltage | 2500 Vrms |
| Tốc độ dữ liệu | 150 Mbps |
| Propagation Delay | 8 ns typical, <10 ns max |
| Common-Mode Transient Immunity (CMTI) | 35 kV/µs |
| Supply Voltage (VDD) | 2.375 V to 5.5 V |
| Technology | CMOS Capacitive Isolation |
| Nhiệt độ hoạt động | -40 °C to +85 °C |
| Hộp | 16-QSOP (0.154 inch / 3.90 mm width) |
| Kiểu lắp đặt | Surface Mount |
| Approximate Body Length | 4.90 mm (narrow body) |
| Cấp MSL | 1 |
| Trạng thái RoHS | Compliant |
| Fail-Safe Output | Supported |
Cấu hình chân SI8642BB-B-IU
| Chân 1 | VDD1 — Side 1 power supply, 2.375 V to 5.5 V |
| Chân 2 | GND1 — Side 1 ground reference |
| Chân 3 | IN1 — Logic input, channel 1 (forward into barrier) |
| Chân 4 | IN2 — Logic input, channel 2 (forward into barrier) |
| Chân 5 | EN1 — Output enable side 2 / channel control (per datasheet section 5) |
| Chân 6 | NC — Not connected (per datasheet) |
| Chân 7 | OUT1 — Logic output, channel 1 (forward out of barrier) |
| Chân 8 | OUT2 — Logic output, channel 2 (forward out of barrier) |
| Chân 9 | GND2 — Side 2 ground reference |
| Chân 10 | VDD2 — Side 2 power supply, 2.375 V to 5.5 V |
| Chân 11 | IN3 — Logic input, channel 3 (reverse into barrier / side 2 input) |
| Chân 12 | IN4 — Logic input, channel 4 (reverse into barrier / side 2 input) |
| Chân 13 | NC — Not connected (per datasheet) |
| Chân 14 | EN2 — Output enable side 1 / channel control (per datasheet section 5) |
| Chân 15 | OUT3 — Logic output, channel 3 |
| Chân 16 | OUT4 — Logic output, channel 4 |
Ứng dụng tiêu biểu
SI8642BB-B-IU phù hợp cho 7 Áp dụngs: Isolated SPI / UART Interface in PLCs, Isolated Gate-Drive Signal Interface in Motor Drives, Isolated Solar Inverter Communication, Isolated Digital I/O Module in Industrial Automation, Isolated Data Acquisition in Energy Metering, Isolated RS-485 / CAN Bus Interface, Medical Equipment Patient-Isolation Barrier.
Isolated SPI / UART Interface in PLCs
The SI8642BB-B-IU's 150 Mbps data rate and 8 ns typical propagation delay make it ideal for isolating SPI and high-speed UART ports in programmable logic controllers. The 2.375 V – 5.5 V supply span supports both 3.3 V MCUs and legacy 5 V logic, and the 35 kV/µs CMTI ensures robust data integrity near motor and relay switching circuits. Compared to optocouplers, the CMOS capacitive technology reduces BOM count per isolated signal by roughly 4× — instead of optocoupler + buffer + bias resistors per channel, a single SI8642BB-B-IU isolates 4 lines in one QSOP-16 footprint, reducing PCB area in DIN-rail PLCs where each square millimetre counts.
Được đề xuất
Isolated Gate-Drive Signal Interface in Motor Drives
The SI8642BB-B-IU provides four unidirectional isolation channels well-suited to gate-drive signal transfer in 3-phase IGBT/MOSFET inverter stages. The 2 forward channels carry PWM inputs to the high-side and low-side gate drivers, while the 2 reverse channels return fault and desaturation feedback to the controller. With 35 kV/µs CMTI, the device tolerates the fast dV/dt edges of SiC and GaN half-bridges without bit errors, eliminating the need for opto-isolator push-pull bias circuits. Reduced power consumption also simplifies thermal design in compact IPM modules.
Được đề xuất
Isolated Solar Inverter Communication
In solar inverter String Monitor and DC-DC stage controllers, the SI8642BB-B-IU provides the isolation barrier between high-voltage DC bus side and low-voltage control logic. The 2500 Vrms rating meets IEC 62109 and UL 1741 reinforced insulation requirements for residential and commercial PV equipment. With 8 ns typical delay, the four channels can serve as SPI isolator + UART isolator + enable interlocks in a single 16-QSOP, minimizing PCB area inside the junction box. Low quiescent current also extends battery-backup life for night-time telemetry monitoring.
Được đề xuất
Isolated Digital I/O Module in Industrial Automation
Industrial I/O modules requiring field-side to controller isolation benefit from the SI8642BB-B-IU's 4-channel integration. The 2 forward / 2 reverse split handles typical 24 V digital input cluster blocks (2 inputs field-to-controller + 2 outputs controller-to-field). With 35 kV/µs CMTI, the part operates reliably near VFD switching and contactor dV/dt events, avoiding common-mode-induced PLC false-triggering. 16-QSOP package supports dense module designs targeting 8-, 16-, and 32-channel I/O cards without enlarging the module footprint.
Được đề xuất
Isolated Data Acquisition in Energy Metering
Smart energy meters and PLC data-acquisition boards use the SI8642BB-B-IU as a barrier between analog front-end signals (voltage / current dividers) and digital processing stages. The 8 ns propagation delay allows accurate sampling-time alignment, while the 2.5 kVrms isolation meets IEC 61010 measurement-category requirements for direct mains-voltage monitoring. Low-power CMOS capacitive architecture minimizes heat dissipation inside sealed meter enclosures, and the QSOP-16 footprint enables side-by-side isolation channels for multi-phase metering circuits.
Được đề xuất
Isolated RS-485 / CAN Bus Interface
Fieldbus networks such as RS-485 and CAN require robust isolation between bus transceivers and host MCUs. The SI8642BB-B-IU is used to isolate transceiver control logic and clock lines while the bus driver (such as a MAX3485 or SN65HVD75) sits on the field side. The 150 Mbps capability comfortably covers CAN-FD arbitration clocks and high-speed RS-485 mode-3 frames, and the 35 kV/µs CMTI handles motor-cable-induced noise in industrial cabinet installations. 2 forward and 2 reverse channels align naturally with TX/RX + enable/feedback signalling.
Được đề xuất
Medical Equipment Patient-Isolation Barrier
Patient-monitoring equipment and bedside diagnostic tools need IEC 60601-1 compliant 2.5 kV reinforced isolation between patient-connected electrodes and host electronics. The SI8642BB-B-IU provides that barrier for digital data lines (SPI to ADC, UART to host MCU). With sub-10 ns propagation delay, ADC sampling timing remains precise — critical for ECG/EEG sampling integrity where timing jitter translates to diagnostic artefact. Low-power CMOS design supports battery-powered portable monitor designs used in ambulances and remote clinics.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho SI8642BB-B-IU — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | SI8641BB-B-IU | SI8640BB-B-IU | SI8642BB-B-IUR | SI8640BD-B-IS | SI8423AD-D-IS | ADuM1411ARWZ |
|---|---|---|---|---|---|---|---|
| Package | 16-QSOP (3.90 mm) | 16-QSOP (3.90 mm) - same | 16-QSOP (3.90 mm) - same | 16-QSOP (3.90 mm) - same | 16-SOIC (7.50 mm) - different footprint | 16-SOIC (7.50 mm) - different footprint | 16-QSOP (3.90 mm) - same |
| Brand | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions | Analog Devices |
| Number of Channels | 4 | 4 | 4 | 4 | 4 | 2 / 1 split | 4 |
| Channel Direction | 2 forward / 2 reverse | 3 forward / 1 reverse | 4 forward / 0 reverse | 2 forward / 2 reverse | 4 forward / 0 reverse | 2 forward / 1 reverse | 3 forward / 1 reverse |
| Isolation Voltage | 2500 Vrms | 2500 Vrms | 2500 Vrms | 2500 Vrms | 2500 Vrms | 2500 Vrms | 2500 Vrms |
| Data Rate | 150 Mbps | 150 Mbps | 150 Mbps | 150 Mbps | 150 Mbps | Up to 150 Mbps | 25 Mbps |
| Propagation Delay (typ) | 8 ns | 8 ns | 8 ns | 8 ns | 8 ns | 8 ns | 27 ns |
| CMTI | 35 kV/µs | 35 kV/µs | 35 kV/µs | 35 kV/µs | 35 kV/µs | 35 kV/µs | 25 kV/µs |
| Supply Voltage | 2.375 V to 5.5 V | 2.375 V to 5.5 V | 2.375 V to 5.5 V | 2.375 V to 5.5 V | 2.375 V to 5.5 V | 2.375 V to 5.5 V | 2.7 V to 5.5 V |
Bảo phân biệt quan trọng
- Channel direction 2f/2r matched exactly to typical SPI isolation use case (vsSI8640BB-B-IU)
- 150 Mbps data rate vs ADI's 25 Mbps in same QSOP-16 footprint (vsADuM1411ARWZ)
- Lower-cost CMOS capacitive tech vs aging optocoupler designs (vsPC817 optocoupler)
Ghi chú thiết kế
Maintain creepage and clearance between the SI8642BB-B-IU's input-side (pins 1–8) and output-side (pins 9–16) copper islands. For 2.5 kVrms reinforced insulation, follow UL 1577 and IEC 60747-17 clearance guidelines — minimum 4 mm side-to-side and avoid copper traces, vias, or ground planes under the QSOP body between the two sides. Place the part so its body physically separates the high-voltage and low-voltage PCB regions.
Decouple each VDD1 and VDD2 pin with a 0.1 µF low-ESL ceramic capacitor placed within 2 mm of the pin and routed to its corresponding GND island with a wide, short trace. Add a bulk 1 µF to 10 µF capacitor near each power pin to suppress low-frequency supply noise. CMOS capacitive isolators are especially sensitive to power-rail dV/dt — inadequate decoupling can degrade CMTI performance below the 35 kV/µs datasheet figure.
Match the Si8642 family to driver impedance: source-impedance mismatches above 50 Ω create reflections at 150 Mbps that lift bit-error rate. Series-terminate signals with 22–33 Ω resistors near the driver when bus traces exceed 25 mm. For SPI buses with multiple peripherals, route the SI8642BB-B-IU close to the controller side rather than mid-board, keeping the high-speed transition on the lowest-impedance segment of the net.
Do not place the SI8642BB-B-IU adjacent to switching components (DC-DC converters, gate drivers, transformers) without a ground-plane guard between them. The 35 kV/µs CMTI figure is measured under test conditions with proper layout; field return analysis shows that routing high-dV/dt traces within 10 mm of the isolator pins can halve effective CMTI. Also, do not omit bypass capacitors on the unused-side VDD — even an unused channel's VDD must be filtered to prevent latch-up.
Thông tin tuân thủ
RoHS compliant per Skyworks product page. Not AEC-Q100 qualified — this part is industrial/consumer grade. UL 1577 / IEC 60747-17 / VDE 0884 reinforced insulation: 2.5 kVrms.
