SI8422AD-D-IS - 5kV 2-Ch Digital Isolator, 1Mbps | Skyworks
Артикул: SI8422AD-D-IS ✓ Активен| Кол-во | Цена за ед. | Итого |
|---|---|---|
| 1 | $2.65 | $2,65 |
| 10 | $2.32 | $23,20 |
| 100 | $1.95 | $195,00 |
| 500 | $1.68 | $840,00 |
| 1.000 | $1.42 | $1.420,00 |
SI8422AD-D-IS Обзор
A digital isolator is a semiconductor device that transfers logic signals across an electrical isolation barrier using high-frequency carrier modulation rather than direct galvanic connection. Digital isolators (also called galvanic isolators or signal isolators) are a sub-category of interface IC that bridges functional blocks operating at different ground potentials - for example a microcontroller on a 3.3 V logic island and a power-converter gate driver on a high-voltage bus. Compared with traditional optocouplers, digital isolators consume less board area, offer tighter channel-to-channel matching, deliver higher CMTI, and avoid the gradual current-transfer-ratio (CTR) degradation that plagues LEDs.
Key features of this device include a typical propagation delay of 35 ns, a worst-case propagation delay skew below 10 ns, a common-mode transient immunity (CMTI) of 20 kV/µs (minimum), and support for a 2.7 V to 5.5 V supply on either side of the barrier. The two independent unidirectional channels are configured as 1 forward + 1 reverse, which matches the channel count of typical SPI or UART isolation but is the minimum viable count for I2C isolation (most I2C designs need bidirectional channels, for which the bidirectional Si8402 family would be required). All parts in the Si8422 family are safety certified by UL, CSA, and VDE; the wide-body SOIC variant supports reinforced insulation per IEC 60747-17 / IEC 62368-1.
From an architectural perspective, the Si8422 uses a differential RF carrier across the transformer, with the receiver recovering the data by envelope detection. The two independent channels are isolated by separate transformers that share the same high-voltage isolation barrier, giving true channel-to-channel isolation rather than just channel-to-ground isolation. The wide-body 16-SOIC (0.295 in / 7.50 mm) provides the 8 mm creepage/clearance required for reinforced 5 kVrms insulation in industrial and renewable-energy applications.
Typical applications include isolated gate-drive interfaces for industrial motor drives and solar inverters, isolated SPI / UART / GPIO expansion in PLC and industrial control modules, isolated data acquisition front-ends in medical and process-control equipment, isolated RS-485 / RS-232 transceivers, and isolated power-supply feedback paths. The -D- default-LOW output is preferred in fault-tolerant designs where the system should enter a safe state on power loss.
Design considerations include pairing the Si8422 with a high-quality 0.1 µF + 1 µF VDD bypass on each side of the barrier, placing it within 2 mm of the IC to suppress switching-edge ringing, and avoiding PCB traces under the device body that would compromise the 8 mm creepage distance. Its wide-body footprint requires 4-layer stack-up planning when used in consumer-grade 2-layer boards.
This page combines up-to-date distributor stock and pricing, drop-in alternatives in the same SOIC-16W package, and practical design notes that go beyond the manufacturer datasheet's typical-application section.
Аналоги без доработки для SI8422AD-D-IS — тот же корпус, pin-to-pin совместимость. Компоненты в других корпусах, требующие переработки PCB, исключены.
Варианты в этой серии
Модели той же серии, совместимые без доработки с SI8422AD-D-IS (тот же форм-фактор и посадочное место) — отличается по Common-Mode Transient Immunity (CMTI), Package, RoHS Status, Technology, AEC-Q100 Qualification.
Инструмент быстрого сравнения — выберите альтернативные компоненты для сравнения бок о бок:
SI8422AD-D-ISR
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
SI8422BB-D-IS
✅ Прямая замена✓ В наличии
$1.52 / шт.
Открыть даташит →SI8422BD-D-IS
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
SI8422AB-D-IS
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
SI8431BB-D-IS
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
ISO7821DW
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
ISO7421DW
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
SI8422AD-D-IS Характеристики
| Isolation Voltage | 5000 Vrms |
| Каналы | 2 (1 forward + 1 reverse) |
| Maximum Data Rate | 1 Mbps |
| Common-Mode Transient Immunity (CMTI) | 20 kV/µs (minimum) |
| Typical Propagation Delay | 35 ns |
| Propagation Delay Skew | <10 ns (worst case, channel-to-channel) |
| Supply Voltage Range | 2.7 V to 5.5 V (each side) |
| Default Output State (Fail-Safe) | Logic LOW when input side unpowered (D variant) |
| Channel Configuration | Unidirectional, 1 fwd + 1 reverse |
| Technology | RF-coupled CMOS digital isolator (transformer-based) |
| Корпус | Wide-body 16-SOIC, 0.295 in (7.50 mm) |
| Creepage / Clearance | 8 mm (wide-body SOIC) |
| Рабочая температура | -40 °C to +125 °C |
| Safety Certifications | UL, CSA, VDE (Reinforced Insulation per IEC 60747-17 / IEC 62368-1) |
| Статус RoHS | ROHS3 Compliant |
| Уровень MSL | 3 (per JEDEC J-STD-020) |
Конфигурация выводов SI8422AD-D-IS
| Контакт 1 | VDD1 — Side 1 power supply (2.7 V - 5.5 V); bypass with 0.1 µF + 1 µF to GND |
| Контакт 2 | GND1 — Side 1 ground / VSS1 return |
| Контакт 3 | A1 — Side 1 input - Channel 1 (forward), logic input to AOUT1 on side 2 |
| Контакт 4 | A2 — Side 1 input - Channel 2 (return), logic input to BOUT2 on side 2 |
| Контакт 5 | NC — No Connect - leave open per datasheet |
| Контакт 6 | NC — No Connect - leave open per datasheet |
| Контакт 7 | NC — No Connect - leave open per datasheet |
| Контакт 8 | NC — No Connect - leave open per datasheet |
| Контакт 9 | NC — No Connect - leave open per datasheet |
| Контакт 10 | NC — No Connect - leave open per datasheet |
| Контакт 11 | GND2 — Side 2 ground / VSS2 return |
| Контакт 12 | B2 — Side 2 input - Channel 2 reverse input from side 2 to side 1 |
| Контакт 13 | B1 — Side 2 output - Channel 1 forward output (default-LOW on D suffix) |
| Контакт 14 | AOUT2 — Side 1 output - Channel 2 (default-LOW on D suffix) |
| Контакт 15 | NC — No Connect - leave open per datasheet |
| Контакт 16 | VDD2 — Side 2 power supply (2.7 V - 5.5 V); bypass with 0.1 µF + 1 µF to GND |
Типичное применение
SI8422AD-D-IS подходит для 7 применениеs: Isolated Industrial SPI/UART Bridge, Isolated Gate-Drive Communication Channel for Motor Drive, Solar Inverter Feedback Isolation, Medical Patient-Monitoring Signal Isolation, Isolated RS-485 / RS-232 Transceivers in Industrial Fieldbus, PLC and Industrial Control Module I/O Expansion, Isolated Power-Supply Feedback Path.
Isolated Industrial SPI/UART Bridge
The SI8422AD-D-IS is a strong fit for bridging SPI up to ~1 MHz or UART up to 1 Mbaud across the 5 kVrms isolation barrier between a low-voltage logic island and a field-side industrial bus. With 1 forward + 1 reverse unidirectional channel and typical propagation delay of 35 ns, the part cleanly handles SPI SCLK/MOSI on the forward channel and MISO on the reverse direction with 2 channels remaining for chip-select and interrupt. The 20 kV/µs minimum CMTI protects against dv/dt events from the isolated gate driver downstream of the bridge. Compared to a 2.5 kV basic-isolation optocoupler approach, the Si8422 saves board area, eliminates LED aging, and is supported by UL/CSA/VDE certifications for reinforced insulation in IEC 62368-1 systems.
Рекомендуется
Isolated Gate-Drive Communication Channel for Motor Drive
In a three-phase IGBT or SiC MOSFET motor drive, the SI8422AD-D-IS sits between the MCU-side low-voltage ground and the high-voltage DC-bus side ground to carry fault and feedback signals across the isolation barrier. Its 5000 Vrms reinforced rating and 8 mm creepage in wide-body SOIC are well-matched to 400-690 V AC industrial drives. The default-LOW fail-safe behavior of the D suffix is critical for motor-control applications, because it places gate-driver inhibit lines in a safe state when the control-side power supply is removed, avoiding shoot-through during power-up and power-down transients. Two independent channels allow separate fault and enable lines to be isolated with a single small-outline IC.
Рекомендуется
Solar Inverter Feedback Isolation
Solar string inverters and central inverters rely on reinforced isolation to separate the high-voltage DC bus (up to 1500 V) from the low-voltage control and communications section. The SI8422AD-D-IS is well-suited to isolating the feedback loop of an auxiliary SMPS, the trip signal of an overvoltage protection circuit, and the enable line of the IGBT/SiC gate driver. Its 2 independent channels, 5 kVrms reinforced insulation, and 20 kV/µs CMTI handle the very fast dv/dt edges produced by the inverter's 50-100 kHz switching, while remaining small enough to fit a 1 oz copper 4-layer PCB. Wide-body 16-SOIC was historically chosen for this use case because of the 8 mm creepage clearance available from the JEDEC-wide SO footprint.
Рекомендуется
Medical Patient-Monitoring Signal Isolation
Patient-monitoring equipment such as ECG, EEG, and pulse-oximetry front-ends must achieve 5 kV of patient isolation to comply with IEC 60601-1 and ANSI/AAMI ES60601-1. The SI8422AD-D-IS, with UL/CSA/VDE certification and 5000 Vrms reinforced insulation, fits this requirement when only a few low-data-rate signals (typically under 1 Mbps) need to cross the isolation barrier. Its 35 ns propagation delay is acceptable for sampling rates of 1 kSPS - 10 kSPS used in patient monitoring, and 2 channels are enough to isolate both a serial data line and a synchronization pulse. The CMOS-based RF technology avoids the current-transfer-ratio (CTR) aging of optocouplers, which is critical for medical devices expected to provide decades of service life.
Рекомендуется
Isolated RS-485 / RS-232 Transceivers in Industrial Fieldbus
RS-485 is the dominant industrial fieldbus for factory-automation networks, and Modbus, PROFIBUS, and BACnet often need galvanic isolation to break ground loops and survive surge events. The SI8422AD-D-IS isolates the low-voltage UART side of an RS-485 transceiver (e.g. THVD1424) from the bus-side high-voltage common-mode domain. With 1 forward + 1 reverse channel, it carries TX and RX cleanly across the barrier, while additional GPIO lines for direction control or fault indication can use the spare channel. The 5 kVrms reinforced rating beats the 2.5 kV basic isolation of most RS-485 designs, and the wide-body SOIC footprint supports 8 mm creepage on standard 4-layer fieldbus PCBs.
Рекомендуется
PLC and Industrial Control Module I/O Expansion
PLC digital-input modules and small-signal-output modules require channel-by-channel galvanic isolation from the backplane logic. The SI8422AD-D-IS fits per-channel isolation of 2-wire slow-control signals such as 24 V proximity-switch inputs or relay-coil drive outputs. Its 2.7 V - 5.5 V wide supply range on each side lets the module-side operate directly from a 3.3 V logic rail and the field-side from a 5 V regulator. The 1 Mbps data rate is well above the de-bounced switch sample rate of a typical PLC digital input. The wide-body SOIC footprint also lets the design use a single shared heatsink-isolation air gap across an entire 8- or 16-channel input card, simplifying mechanical layout and reducing assembly cost.
Рекомендуется
Isolated Power-Supply Feedback Path
Closed-loop isolated DC-DC converters use a TL431 optocoupler or a digital-isolation feedback path to communicate output-voltage regulation across the isolation barrier. The SI8422AD-D-IS replaces the optocoupler in lower-power (<5 W) isolated converters where its 35 ns propagation delay is acceptable for the regulation loop bandwidth (typically 10-50 kHz for these converters). Two channels allow both the FB signal and a synchronization or enable line to share one isolator IC. The 5 kVrms reinforced rating matches the auxiliary-power safety target of IEC 62368-1, and the Si8422 eliminates the optocoupler's CTR drift over time, improving long-term set-point accuracy of the regulated output by 1-2%.
Рекомендуется
Сводка рекомендуемых товаров
Справочные инженерные данные для SI8422AD-D-IS — сравнение, рекомендации по проектированию и информация о соответствии.
Руководство по выбору
Сравнение с аналогами
| Параметр | Этот товар | SI8422AD-D-ISR | SI8422BB-D-IS | SI8422AB-D-IS | ISO7821DW | ISO7421DW |
|---|---|---|---|---|---|---|
| Brand | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions | Texas Instruments | Texas Instruments |
| Package | Wide-Body 16-SOIC, 0.295 in (7.50 mm) | Wide-Body 16-SOIC, 0.295 in (7.50 mm) - same | Wide-Body 16-SOIC, 0.295 in (7.50 mm) - same | Wide-Body 16-SOIC, 0.295 in (7.50 mm) - same | Wide-Body 16-SOIC, 0.295 in (7.50 mm) - same | Wide-Body 16-SOIC, 0.295 in (7.50 mm) - same |
| Isolation Voltage | 5000 Vrms | 5000 Vrms | 5000 Vrms | 2500 Vrms | 8000 Vrms (reinforced) | 2500 Vrms (basic) |
| Maximum Data Rate | 1 Mbps | 1 Mbps | 25 Mbps | 1 Mbps | 100 Mbps | 1 Mbps |
| Channels (Configuration) | 2 (1 fwd + 1 rev) | 2 (1 fwd + 1 rev) | 2 (1 fwd + 1 rev) | 2 (1 fwd + 1 rev) | 2 (1 fwd + 1 rev) | 2 (1 fwd + 1 rev) |
| CMTI (minimum) | 20 kV/µs | 20 kV/µs | 20 kV/µs | 20 kV/µs | 100 kV/µs | 25 kV/µs |
| Default Output (Fail-Safe) | LOW (D suffix) | LOW (D suffix) | LOW (D suffix) | LOW (D suffix) | HIGH (default-LOW variant separately orderable) | Configurable (via pin) |
| Approx. Unit Price (qty 1) | USD 2.65 | USD 2.65 (tape and reel code only) | USD 3.05 | USD 2.20 | USD 4.50 | USD 2.95 |
Ключевые отличия
- Highest isolation rating in the Si8422 family at 5 kVrms reinforced (против SI8422AB-D-IS)
- Lower-cost cross-brand alternative exists with reinforced 5 kVrms (против ISO7421DW)
- Same-footprint cross-brand alternative with higher data rate (против ISO7821DW)
- RF-coupled CMOS technology, no LED aging (против PS2801A-1-A (optocoupler))
Заметки по проектированию
Provide a 0.1 µF X7R bypass within 2 mm of each VDD pin and add a 1 µF to 10 µF bulk capacitor for the entire isolation barrier. The Si8422AD-D-IS draws up to ~6 mA per side at 5 V with both channels toggling at 1 Mbps, so a low-ESR regulator is essential. Do not share a single bypass across both VDD pins because each side has its own reference plane. Estimated: total quiescent ~6 mA per side at 1 Mbps, 3 V supply = 18 mW per side.
Wide-body 16-SOIC has 8 mm of creepage/clearance between side-1 and side-2 pin groups, which is what allows the 5 kVrms reinforced rating. Do NOT route any traces, vias, or copper pours underneath the package body. Keep at least 8 mm of clean board surface between side-1 ground and side-2 ground. On 4-layer stack-ups, ensure inner layer ground planes are also gapped under the SOIC body. On 2-layer consumer-grade boards, the wide-body SOIC may not be feasible; consider 8-pin SOIC narrow-body parts or NB SOIC 4-channel variants instead.
Common pitfalls when substituting the SI8422AD-D-IS: (1) placing the device over a signal trace reduces creepage and voids reinforced isolation; (2) tying pin 5/6/7/8/9/10/15 to ground rather than NC creates extra parasitic capacitance that can degrade CMTI; (3) using a single isolated DC-DC instead of separate bias supplies per side defeats the isolation barrier. Always verify with HiPot and surge testing after PCB changes. Estimated CMTI degradation from a typical layout mistake: 25-40%.
At 1 Mbps the Si8422AD-D-IS is well below its CMRR-limited rise-time budget - the 35 ns propagation delay and <10 ns channel-skew mean the device can drive 50 pF loads cleanly. Place a 33 Ω-100 Ω series resistor at the input pin to dampen reflections when driving long PCB traces (>5 cm) or backplanes. For very fast edges (>100 V/ns) from the upstream driver, add a 4.7 kΩ pull-up to align the rate-of-rise with the isolator's guaranteed operating range.
Информация о соответствии
ROHS3 compliant per DigiKey product page. Safety certified by UL, CSA, and VDE (file numbers listed in datasheet). Wide-body 16-SOIC supports reinforced insulation per IEC 60747-17 / IEC 62368-1.
