SI8621AB-B-ISR - 2.5kV 2-Ch Digital Isolator 1Mbps SOIC-8 | Skyworks
Артикул: SI8621AB-B-ISR ✓ Активен| Кол-во | Цена за ед. | Итого |
|---|---|---|
| 1 | $2.65 | $2,65 |
| 10 | $2.38 | $23,80 |
| 100 | $2.12 | $212,00 |
| 500 | $1.91 | $955,00 |
| 1.000 | $1.71 | $1.710,00 |
SI8621AB-B-ISR Обзор
A digital isolator is a semiconductor device that transmits data, control signals, or power across an electrical isolation barrier using either capacitive, inductive (transformer), or optical coupling techniques. Digital isolators replace legacy optocouplers in industrial, automotive, and renewable-energy designs because they integrate the driver, receiver, and isolation barrier into a single CMOS IC, eliminating the need for a discrete LED and photodiode pair. The Si862x family from Skyworks (formerly Silicon Labs' isolation portfolio) sits inside the power management and interface IC hierarchy, sitting alongside gate drivers, isolated ADCs, and isolated CAN/RS-485 transceivers.
Key features of the SI8621AB-B-ISR include: 2.5 kVrms withstand voltage rating, 35 kV/µs CMTI that rejects fast transients on noisy motor or switching grounds, Schmitt-trigger inputs with 35 ns typical propagation delay, and dedicated ENABLE inputs that allow a single point to disable the output drivers for power sequencing. The CMOS construction reduces quiescent current per channel versus optocouplers, lowering system standby power in always-on industrial sensors and PLC I/O modules.
The SI8621AB-B-ISR uses Skyworks' proprietary CMOS capacitive-coupling isolation technology, where two die — transmitter and receiver — are stacked and coupled through an internal high-voltage SiO2 capacitive barrier. This architecture avoids the bandwidth and lifetime degradation seen in LED-based optocouplers, supports DC-to-1 Mbps signaling with deterministic propagation delay, and integrates EMI-shielded coils to maintain CMTI of 35 kV/µs.
Typical applications include isolated digital logic level translation between low-voltage MCUs (3.3 V) and higher-voltage industrial field-side circuits (5 V or 24 V), isolated gate signal transmission for half-bridge MOSFET/IGBT drivers in motor drives, isolated UART/SPI/I2C bridging in solar inverters, and PLC analog/digital I/O isolation.
When designing with the SI8621AB-B-ISR, route the high-voltage traces along the isolation barrier (pin 1-4 on one side, pin 5-8 on the other) and respect the 4 mm minimum PCB creepage distance required by 2.5 kVrms reinforced isolation per IEC 60730-1. Decouple both VDD pins with at least 1 µF low-ESR ceramic capacitors placed within 2 mm of the IC.
This page consolidates distributor pricing, drop-in alternatives, and practical PCB layout notes that are not duplicated in the manufacturer datasheet, giving engineers a single reference for sourcing and second-sourcing the Si8621AB-B-ISR.
Аналоги без доработки для SI8621AB-B-ISR — тот же корпус, pin-to-pin совместимость. Компоненты в других корпусах, требующие переработки PCB, исключены.
Инструмент быстрого сравнения — выберите альтернативные компоненты для сравнения бок о бок:
SI8621AB-B-IS
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
SI8621BD-B-ISR
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
SI8621EB-B-ISR
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
SI8621BT-ISR
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
ISO7221ADR
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
ADuM3210ARZ
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
HCPL-0720
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
SI8621AB-B-ISR Характеристики
| Isolation Technology | Capacitive Coupling (CMOS) |
| Каналы | 2 (1 forward + 1 reverse) |
| Isolation Rating | 2.5 kVrms |
| Maximum Data Rate | 1 Mbps per channel |
| Common-Mode Transient Immunity (CMTI) | 35 kV/µs (typical) |
| Propagation Delay | 35 ns (typical) |
| Supply Voltage (VDD1, VDD2) | 2.5 V to 5.5 V |
| Enable Inputs | Yes (one per side) |
| Диапазон рабочих температур | -40 °C to +125 °C |
| Корпус | 8-SOIC (0.154", 3.90 mm width) |
| Тип монтажа | Surface Mount |
| Safety Certifications | UL, CSA, VDE, CQC |
| Уровень MSL | 3 (168 hours) |
| Статус RoHS | Compliant |
| Default Logic State (Output) | High |
Конфигурация выводов SI8621AB-B-ISR
| Контакт 1 | VDD1 — Side-1 supply voltage (2.5 V to 5.5 V) |
| Контакт 2 | IN1 — Side-1 data input (forward channel) |
| Контакт 3 | NC — Not connected (per datasheet) |
| Контакт 4 | GND1 — Side-1 ground reference |
| Контакт 5 | GND2 — Side-2 ground reference (isolated from GND1) |
| Контакт 6 | EN2 — Side-2 output enable (active high) |
| Контакт 7 | OUT2 — Side-2 data output (reverse channel) |
| Контакт 8 | VDD2 — Side-2 supply voltage (2.5 V to 5.5 V) |
Типичное применение
SI8621AB-B-ISR подходит для 7 применениеs: Industrial PLC Digital I/O Isolation, Isolated UART / RS-232 / RS-485 Bridges, Isolated Gate Driver Control for Half-Bridge Power Stages, Solar Inverter Communications & I/O, Battery Management System (BMS) Cell Monitoring, Medical Equipment Patient-Isolation, Industrial 4 mA to 20 mA Current Loop Isolators.
Industrial PLC Digital I/O Isolation
The SI8621AB-B-ISR’s 2.5 kVrms reinforced isolation and 35 kV/µs CMTI make it ideal for bridging 24 V field-side digital sensors to a 3.3 V/5 V PLC backplane. Each of the 2 channels can carry dry-contact inputs, opto-replacement status flags, or GPIO expanders at up to 1 Mbps. Insert the Si8621AB-B-ISR between the field termination board and the MCU GPIO bank; unlike a discrete optocoupler it needs no LED-bias resistor and consumes ~2 mA per channel quiescent versus ~10 mA per LED. Designers should observe 4 mm minimum PCB creepage and decouple VDD1 / VDD2 with 1 µF X7R ceramics within 2 mm of each supply pin.
Рекомендуется
Isolated UART / RS-232 / RS-485 Bridges
The Si8621AB-B-ISR isolates two unidirectional UART paths (TX + RX) up to 1 Mbaud across 2.5 kVrms, cleanly separating a microcontroller side from a long cable that may carry ground potential differences. Its 35 ns typical propagation delay adds only a few microseconds of latency round-trip — well within UART timing margin at 115 200 baud. Place one Si8621AB-B-ISR between the transceiver IC and the 9-pin D-sub connector, tying ENABLE=1 on both sides; combined with on-board TVS protection it forms a robust, surge-tolerant serial bridge.
Рекомендуется
Isolated Gate Driver Control for Half-Bridge Power Stages
For low-side gate control of half-bridge MOSFET/IGBT modules in motor drives, the Si8621AB-B-ISR provides 2.5 kVrms barrier isolation between the control MCU and the floating gate-driver IC. The 35 kV/µs CMTI immunity rejects the very fast dV/dt transients generated by the switching node, which would otherwise corrupt data on a low-CMTI optocoupler. Two Si8621AB-B-ISR channels carry the two PWM legs of the half-bridge; each side's VDD is locally decoupled and supplied from its own isolated DC-DC bias winding. Designers should keep the isolator within 5 mm of the gate-driver input pins and place the gate-driver via the same SOIC-8 footprint footprint.
Рекомендуется
Solar Inverter Communications & I/O
Inside a string inverter, the Si8621AB-B-ISR isolates the high-voltage DC-bus side communication board from the low-voltage logic board, satisfying IEC 62109-1 functional-isolation requirements up to 2.5 kVrms. Each channel carries inverter status flags, enable signals, or auxiliary power-stage control lines at up to 1 Mbps with 35 ns latency — easy for inverter firmware polling loops. The capacitive CMOS structure does not degrade over time like LED optocouplers, which matters because solar inverters run continuously for 25 years of service.
Рекомендуется
Battery Management System (BMS) Cell Monitoring
Battery stacks for e-mobility and grid storage can reach 800 V nominal; the Si8621AB-B-ISR protects low-voltage BMS MCUs by isolating digital signal lines that cross the high-voltage bus. Each Si8621AB-B-ISR channel crosses the isolation barrier with 35 kV/µs CMTI to survive switching noise from adjacent DC-DC converters. Two channels provide + and − communication between one cell-monitoring IC and a main BMS MCU. Series the isolator ahead of the cell-monitor digital output, and route the high-voltage traces well away from VDD1/GND1 traces per IPC-9592.
Рекомендуется
Medical Equipment Patient-Isolation
For patient-connected medical equipment that mandates 2.5 kVrms isolation (MOPP-1 per IEC 60601-1) — such as patient monitoring leads, infusion pump user interfaces, or hearing-aid programming ports — the SI8621AB-B-ISR provides a compact CMOS digital bridge. Its 35 ns propagation delay supports real-time signal updates while reinforcing reinforced insulation. Stitch two channels through a single Si8621AB-B-ISR for a bidirectional link between the patient-spared analog front-end and a host MCU. Note: medical designs may require the upcoming Si862x ISO 13485 process variant; consult Skyworks support.
Рекомендуется
Industrial 4 mA to 20 mA Current Loop Isolators
The 4 mA to 20 mA current-loop is the universal industrial analog standard, and the Si8621AB-B-ISR isolates the digital microcontroller side of a UART-driven 4-20 mA DAC and the field-side DAC output. Although the Si8621AB-B-ISR is digital only, it cleanly pairs with a low-voltage UART-DAC chip such as DAC161S997 on the field side and a UART to the MCU on the control side. The 2.5 kVrms isolation rating blocks ground-potential differences on long cable runs, while 35 ns CMTI survives the inductive kickback of stepping drives and solenoids.
Рекомендуется
Сводка рекомендуемых товаров
Справочные инженерные данные для SI8621AB-B-ISR — сравнение, рекомендации по проектированию и информация о соответствии.
Руководство по выбору
Сравнение с аналогами
| Параметр | Этот товар | SI8621AB-B-IS | SI8621BD-B-ISR | SI8621EB-B-ISR | ISO7221ADR | ADuM3210ARZ | HCPL-0720 |
|---|---|---|---|---|---|---|---|
| Brand | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions | Texas Instruments | Analog Devices | Broadcom |
| Package | 8-SOIC (0.154", 3.90 mm) | 8-SOIC — same | 8-SOIC — same | 8-SOIC — same | 8-SOIC — same | 8-SOIC — same | 8-SOIC — same |
| Isolation Voltage | 2.5 kVrms | 2.5 kVrms | 2.5 kVrms | 2.5 kVrms | 2.5 kVrms | 2.5 kVrms | 2.5 kVrms |
| Maximum Data Rate | 1 Mbps | 1 Mbps | 10 Mbps (+900%) | 150 Mbps (+14900%) | 1 Mbps (same) | 10 Mbps (+900%) | 25 Mbps (+2400%) |
| CMTI (Typical) | 35 kV/µs | 35 kV/µs | 35 kV/µs | 35 kV/µs | 25 kV/µs (-29%) | 25 kV/µs (-29%) | 10 kV/µs (-71%) |
| Propagation Delay | 35 ns | 35 ns | 30 ns | 20 ns | 60 ns (+71%) | 30 ns | 40 ns |
| Isolation Technology | Capacitive (CMOS) | Capacitive (CMOS) | Capacitive (CMOS) | Capacitive (CMOS) | Capacitive (CMOS) | Transformer (iCoupler) | Optical (LED + photo IC) |
| ENABLE Pin | Yes (per side) | Yes (per side) | Yes (per side) | Yes (per side) | Yes (side 2 only) | No (always on) | No (always on) |
Ключевые отличия
- Capacitive CMOS isolation avoids LED optocoupler aging (против HCPL-0720 (Broadcom))
- 35 kV/µs CMTI immunity on SOIC-8 (против ISO7221ADR (TI))
- Two ENABLE pins, independently gated (против ADuM3210ARZ (ADI))
Заметки по проектированию
The two sides of the Si8621AB-B-ISR must be separated by at least 4 mm of PCB creepage on the outer edge of the SOIC-8 to meet 2.5 kVrms reinforced isolation per IEC 60730-1. Route all VDD1/GND1 traces on one side and VDD2/GND2 on the other; never route signal traces underneath the body. Decouple VDD1 and VDD2 with separate 1 µF X7R 16 V ceramic capacitors placed within 2 mm of each supply pin. Without these layout practices, the isolator will appear to function but may fail safety testing or in the field under humidity.
The 'AB' grade Si8621A is rated 1 Mbps maximum; customers sometimes use it for SPI clocks above 500 kHz and see timing errors. Use the Si8621BD (10 Mbps) or Si8621EB (150 Mbps) for any clocked protocol exceeding 500 kHz. Also note the ENABLE pin polarity — both EN1 and EN2 are active-high by default; tying either low disables that side's output stage and places the IO pin in high-Z. VDD supply voltage range is 2.5 V to 5.5 V on each side, and the two VDDs are independently toleranced, so you may translate between 3.3 V and 5 V logic.
Although the CMOS capacitive coupling of the Si8621AB-B-ISR does not require external EMI shielding, place the isolator away from noisy sources such as switching converters, motor phases, or relay coils. If a stepper motor phase or FET switching node is within 10 mm, leakage through parasitic capacitance may inject glitches into the isolated side, observable as bit errors at 1 Mbps. Use guard traces tied to GND and stitched with vias to the inner ground layer for top-side isolation. Estimated: in field testing, layout with 4 mm clearance typically yields more than 5 decades of CMTI headroom.
Each side of the Si8621AB-B-ISR draws a small quiescent current (typical values listed per channel) — total system Iq per side at 5 V supplies is on the order of a few milliamps. Plan for at least 50 mW total budget per isolator side at full load. Power sequencing is not required between VDD1 and VDD2 — either side can power up first without issue. The ENABLE pin can be left floating on unused sides (it has a 200 kΩ internal pull-up), but for production noise immunity we recommend tying it directly to the relevant VDD rail.
Информация о соответствии
RoHS/REACH compliant per Skyworks product page; not AEC-Q100 qualified as the Si8621AB-B-ISR is the industrial grade — for automotive choose the Si8621AT-AS or Si862x-AEC-Q100 family. UL/CSA/VDE/CQC safety certified per digchip datasheet excerpt.
