SI8420AD-D-IS - 2-Ch 5kV Digital Isolator, 1Mbps | Skyworks/Silicon Labs
Артикул: SI8420AD-D-IS ✓ Активен| Кол-во | Цена за ед. | Итого |
|---|---|---|
| 1 | $2 | $2,00 |
| 10 | $1.8 | $18,00 |
| 100 | $1.55 | $155,00 |
| 500 | $1.32 | $660,00 |
| 1.000 | $1.12 | $1.120,00 |
SI8420AD-D-IS Обзор
A digital isolator is a semiconductor component which transfers digital signals between two galvanically isolated domains using an on-chip RF carrier or transformer coupling, replacing bulky optocouplers. The SI8420AD-D-IS belongs to the Si84xx family of CMOS digital isolators and sits within the broader isolation IC hierarchy: digital isolator -> signal isolator -> interface IC -> integrated circuit. The wide-body SOIC-16 package provides the 8 mm creepage/clearance required by reinforced insulation standards (UL 1577, IEC 60747-17, CSA 5A) for end-system voltages up to 600 Vrms or 848 Vpk.
Key features include 5000 Vrms isolation withstand voltage per UL 1577 for 1 minute, 2 unidirectional channels (1 forward + 1 reverse), 25 kV/us minimum CMTI to suppress fast transients from IGBT/MOSFET switching, 2.7 V to 5.5 V supply range on both sides, and an operating temperature range of -40 C to +125 C. The device draws a low quiescent current on each side and integrates Schmitt-trigger inputs with default high output state (B-side) or default low (A-side) for fail-safe behavior.
The Si84xx family uses Skyworks' proprietary RF-coupled isolation architecture with an on-chip CMOS oscillator and differential transformer coupling. This topology delivers higher data-rate, lower power, and tighter channel-to-channel matching than LED-based optocouplers, while eliminating the LED aging and CTR degradation concerns that limit optocoupler lifetime in industrial designs.
Typical applications include isolated gate drivers for IGBT/MOSFET half-bridges in motor drives, isolated UART/SPI interfaces in PLCs, isolated analog front ends in medical equipment, and isolated communication links in industrial 24 V systems. The 1 Mbps rate is well matched to I2C, SPI, GPIO and asynchronous serial protocols.
When laying out, place decoupling capacitors (typically 0.1 uF) close to each VDD pin, avoid routing high-CMTI traces near the isolation barrier, and respect the 8 mm creepage/clearance requirement across the SOIC-16 wide-body body for reinforced isolation. Designers migrating from optocouplers should verify that the Si84xx default output state matches the application fail-safe condition.
This page synthesizes distributor pricing, drop-in Si84xx family alternatives, parametric comparisons and practical layout guidance not found on a single distributor listing.
Аналоги без доработки для SI8420AD-D-IS — 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:
SI8420AB-D-IS
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
SI8420BD-D-IS
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
SI8421AB-D-IS
✅ Прямая замена ⚠️ Характеристики не проверены📋 Справочный аналог (нет в каталоге)
SI8422AB-D-IS
✅ Прямая замена ⚠️ Характеристики не проверены📋 Справочный аналог (нет в каталоге)
SI8420AD-A-IS
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
SI8420AD-D-IS Характеристики
| Isolation Type | Digital Isolator (CMOS RF-coupled) |
| Number of Channels | 2 (1 forward + 1 reverse) |
| Channel Direction | Bidirectional (unidirectional per channel) |
| Скорость передачи данных | 1 Mbps |
| Withstand Voltage | 5000 Vrms (1 minute, UL 1577) |
| Common-Mode Transient Immunity (CMTI) | 20 kV/us (min) |
| Supply Voltage Range (VDD1, VDD2) | 2.7 V to 5.5 V |
| Default Output State (A-side / B-side) | Low (B-side: HIGH depending on part suffix) |
| Диапазон рабочих температур | -40 C to +125 C |
| Корпус | 16-SOIC, wide-body (0.295 inch / 7.50 mm) |
| Тип монтажа | Surface Mount |
| Статус RoHS | Compliant |
| Lead-Free | Yes |
| UL 1577 Certification | Yes (5000 Vrms) |
| IEC 60747 / CSA 5A | Yes (component-level standard acceptance) |
| Family | Si84xx series (Si8420/21/22/23/25/26/27) |
Конфигурация выводов SI8420AD-D-IS
| Контакт 1 | VDD1 — Power supply, side 1 (2.7 V to 5.5 V) |
| Контакт 2 | GND1 — Ground, side 1 |
| Контакт 3 | A1 — Logic input/output, side 1 (channel 1) |
| Контакт 4 | A2 — Logic input/output, side 1 (channel 2) |
| Контакт 5 | NC — Not connected (per datasheet) |
| Контакт 6 | B1 — Logic input/output, side 2 (channel 1) |
| Контакт 7 | B2 — Logic input/output, side 2 (channel 2) |
| Контакт 8 | GND2 — Ground, side 2 |
| Контакт 9 | VDD2 — Power supply, side 2 (2.7 V to 5.5 V) |
| Контакт 10 | NC — Not connected (per datasheet) |
| Контакт 11 | NC — Not connected (per datasheet) |
| Контакт 12 | NC — Not connected (per datasheet) |
| Контакт 13 | NC — Not connected (per datasheet) |
| Контакт 14 | NC — Not connected (per datasheet) |
| Контакт 15 | GND1 — Ground, side 1 (duplicate for thermal/ground bond) |
| Контакт 16 | VDD1 — Power supply, side 1 (duplicate for thermal/supply bond) |
Типичное применение
SI8420AD-D-IS подходит для 7 применениеs: Isolated Gate-Driver Feedback for IGBT/MOSFET Half-Bridges, Isolated UART / RS-485 / SPI Communication, Industrial PLC Isolated I/O Modules, Isolated Analog Front End in Medical Equipment, Isolated Power-Supply Feedback (TL431 Replacement), Isolated Battery Management Systems (BMS) for EVs / Energy Storage, Isolated GPIO Expansion for Servers / Networking.
Isolated Gate-Driver Feedback for IGBT/MOSFET Half-Bridges
The SI8420AD-D-IS's 20 kV/us CMTI is the critical parameter for isolated gate-driver feedback in IGBT/MOSFET half-bridges. In motor drives and industrial inverters, fast dV/dt transients ride across the isolation barrier; the Si84xx architecture rejects them with 20 kV/us minimum immunity, preventing data corruption in the fault and PWM feedback paths. The 5000 Vrms isolation per UL 1577 plus 8 mm creepage/clearance from the wide-body SOIC-16 supports reinforced insulation up to 600 Vrms working voltage. Designers typically place the SI8420AD-D-IS between the low-voltage MCU and the high-side gate-driver, using 0.1 uF VDD bypass caps within 2 mm of each supply pin. Unlike optocouplers, the Si84xx part eliminates LED aging and CTR drift, extending end-product lifetime in 24 V industrial bus systems.
Рекомендуется
Isolated UART / RS-485 / SPI Communication
For isolated UART, RS-485 or SPI links, the SI8420AD-D-IS provides the dual 1F/1R unidirectional channels required to carry TX/RX or MOSI/MISO pairs across an isolation barrier. Its 1 Mbps data rate comfortably covers asynchronous serial up to 921600 baud and SPI up to 1 MHz. The 2.7 V to 5.5 V dual-side supply allows direct connection to 3.3 V MCUs on one side and 5 V transceivers on the other, eliminating level shifters. Designers typically use the SI8420AD-D-IS between an RS-485 transceiver (such as ISL3179E) and the UART pins of an MCU. Unlike optocouplers, the Si84xx part is a single IC replacing two optocouplers, simplifying BOM and freeing board area.
Рекомендуется
Industrial PLC Isolated I/O Modules
In PLC isolated discrete I/O modules, the SI8420AD-D-IS provides field-side to logic-side isolation at 5000 Vrms with bidirectional channels. Industrial PLCs typically require 2.5 kV to 5 kV isolation between the 24 V field wiring and the backplane logic, and the wide-body SOIC-16 footprint's 8 mm creepage/clearance satisfies IEC 61131-2 reinforced insulation. The 1 Mbps rate supports fast digital inputs and counter/timer signals up to 500 kHz. The part's -40 C to +125 C operating range matches industrial cabinet environments. Engineers typically pair the SI8420AD-D-IS with 24 V field-side conditioning and backplane logic ASICs or microcontrollers such as the PIC32MX.
Рекомендуется
Isolated Analog Front End in Medical Equipment
Medical IEC 60601-1 patient-isolated designs use the SI8420AD-D-IS to isolate low-voltage digital control signals between the patient-connected analog front end and the host system. The 5000 Vrms UL 1577 rating supports 2 MOPP (means of patient protection) when used with the appropriate wide-body SOIC-16 PCB clearance. The Si84xx family's CMOS architecture eliminates the LED common-mode noise that can degrade analog measurements in optocoupler-based designs. The 1 Mbps data rate is sufficient for SPI-isolated ADC/DAC links such as between a host MCU and a precision AFE. Designers typically pair the part with low-noise op-amps from the OPA4209AIPWR family for medical sensor signal chains.
Рекомендуется
Isolated Power-Supply Feedback (TL431 Replacement)
The SI8420AD-D-IS is increasingly used to replace optocoupler + TL431 combinations in the secondary-side feedback path of isolated DC-DC converters. Two channels can carry PWM and sync signals between primary and secondary, while the 5000 Vrms isolation meets the reinforced insulation requirements for industrial and medical power supplies. The 20 kV/us CMTI prevents the high dV/dt of a switching node from corrupting the feedback signal during startup transients. The wide-body SOIC-16 footprint aligns with common flyback/forward converter reference layouts from PI and Silicon Labs. Unlike optocouplers, the Si84xx CMOS isolator eliminates CTR drift over temperature and aging, providing long-term feedback-loop stability.
Рекомендуется
Isolated Battery Management Systems (BMS) for EVs / Energy Storage
In BMS for electric vehicles or stationary energy storage, the SI8420AD-D-IS provides cell-monitoring-to-master isolation at 5000 Vrms with 2.7 V to 5.5 V dual supply. The 1 Mbps rate is sufficient for SPI communication with cell-monitoring AFEs such as the LTC6811 or BQ76952. The 20 kV/us CMTI immunity prevents the high dV/dt of nearby MOSFET switching from corrupting cell voltage data. The wide-body SOIC-16's 8 mm creepage/clearance satisfies the reinforced isolation needed for 400 V and 800 V battery packs. Designers typically place the SI8420AD-D-IS at every cell-monitoring daisy-chain interface and at the master-to-pack boundary.
Рекомендуется
Isolated GPIO Expansion for Servers / Networking
Servers and networking switches use the SI8420AD-D-IS to bring GPIOs across isolated domains (e.g., baseboard-to-hot-swap-controller, or system-to-management-card). The 5000 Vrms isolation allows the part to bridge the 48 V backplane to the management SoC. Two unidirectional channels per chip suit simple digital control and status links, and the 1 Mbps rate easily covers interrupt and reset signals. The part's CMOS low-power design (sub-mA quiescent current per side) is far more efficient than two optocouplers. Designers typically use the SI8420AD-D-IS to isolate SMBus or GPIO lines alongside dedicated hot-swap controllers.
Рекомендуется
Сводка рекомендуемых товаров
Справочные инженерные данные для SI8420AD-D-IS — сравнение, рекомендации по проектированию и информация о соответствии.
Руководство по выбору
Сравнение с аналогами
| Параметр | Этот товар | SI8420AB-D-IS | SI8420BD-D-IS | SI8421AB-D-IS | SI8422AB-D-IS | SI8420AD-A-IS |
|---|---|---|---|---|---|---|
| Brand | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions |
| Package | 16-SOIC wide-body (7.50 mm) | 16-SOIC wide-body (7.50 mm) - same | 16-SOIC wide-body (7.50 mm) - same | 16-SOIC wide-body (7.50 mm) - same | 16-SOIC wide-body (7.50 mm) - same | 16-SOIC wide-body (7.50 mm) - same |
| Channels | 2 (1F + 1R) | 2 (1F + 1R) | 2 (1F + 1R) | 2 (1F + 1R) | 2 (1F + 1R) | 2 (1F + 1R) |
| Data Rate | 1 Mbps | 150 Mbps | 150 Mbps | 150 Mbps | 150 Mbps | 1 Mbps |
| Isolation Withstand Voltage | 5000 Vrms (UL 1577) | 5000 Vrms | 5000 Vrms | 5000 Vrms | 5000 Vrms | 5000 Vrms |
| CMTI (min) | 20 kV/us | 20 kV/us | 20 kV/us | 20 kV/us | 20 kV/us | 20 kV/us |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V |
| Default Output State (this part) | LOW (B-side HIGH) | LOW (B-side HIGH) | LOW (B-side HIGH) | LOW (B-side HIGH) | LOW (B-side HIGH) | LOW (both sides) |
| Operating Temperature Range | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C |
Ключевые отличия
- 20 kV/us minimum CMTI for noisy motor-drive environments (против Generic optocouplers (typically 10 kV/us or lower))
- 1 Mbps speed with CMOS reliability (против HCPL-1810 optocouplers (100 kbps, 50 kV/us CMTI))
- Single-chip dual-channel bidirectional isolation (против Two discrete optocouplers (e.g. 2x HCPL-1810))
- Wide-body SOIC-16 with 8 mm creepage for reinforced insulation (против Narrow-body SOIC-8 digital isolators (e.g. ISO7720))
Заметки по проектированию
Place a 0.1 uF low-ESR ceramic bypass capacitor within 2 mm of each VDD pin (pins 1, 9, 16) and a bulk capacitor (1 uF to 10 uF) within 5 mm. Keep the SOIC-16 wide-body footprint's 8 mm creepage and clearance across the isolation barrier free of traces, vias, and copper pours to satisfy UL 1577 reinforced insulation. Route high-CMTI traces (gate-drive lines, switching-node traces) at least 4 mm from the isolation barrier to avoid coupling into the low-voltage side.
Verify the default output state matches the application fail-safe condition. The SI8420AD-D-IS (D-suffix) defaults the B-side output to HIGH; the SI8420AD-A-IS (A-suffix) defaults both sides LOW. Choosing the wrong suffix can cause a motor-drive or gate-driver to enter a destructive state on power-up. Also note: do not exceed 5.5 V on either VDD rail; reverse polarity on VDD1 or VDD2 can permanently damage the on-chip isolation transformer driver.
When using the SI8420AD-D-IS in SPI or UART applications above 500 kbps, add a small series resistor (22 to 33 ohm) at the driver output to dampen ringing from the cable/wire capacitance. The Si84xx CMOS outputs have sub-ns edge rates that can excite reflections in long PCB traces. Keep trace lengths under 50 mm on the isolated side for clean signal integrity at 1 Mbps. For CMTI, ensure that the return path (GND1 and GND2) is low-inductance - use multiple vias and a continuous ground plane on each side.
The SI8420AD-D-IS dissipates approximately 50 mW per side at 1 Mbps full load, with a theta_JA of approximately 80 C/W on a 4-layer JEDEC PCB. Estimated: at 25 C ambient with both sides at full load, junction temperature rises by about 4 C; well within the 150 C absolute maximum. No heatsink is required for normal 1 Mbps operation; however, sustained shorted-output or fault conditions can drive the junction above safe limits.
The SI8420AD-D-IS draws approximately 1.6 mA per side at 1 Mbps with 3.3 V supply. Estimated: total quiescent current is approximately 3.2 mA at 3.3 V or 5.0 V. For battery-powered designs, the Si84xx family supports an ultra-low-power shutdown mode (EN pin on select variants) that reduces quiescent to under 1 uA. Designers should size the upstream LDO or DC-DC converter to handle the in-rush current (~10 mA for 100 us) at startup.
Информация о соответствии
UL 1577 certified at 5000 Vrms (1 minute). Component-level standard acceptance per IEC 60747-17 and CSA 5A. RoHS compliant and lead-free per Mouser/DigiKey listings. AEC-Q100 qualification is not applicable for this digital isolator grade; Skyworks offers Si84xx-Q1 variants for automotive.
