SI8400AB-B-ISR - 2.5kV I2C Digital Isolator | Skyworks
N.º da peça: SI8400AB-B-ISR ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $7.82 | $7,82 |
| 10 | $7.35 | $73,50 |
| 100 | $6.95 | $695,00 |
| 500 | $6.55 | $3.275,00 |
| 1.000 | $6.1 | $6.100,00 |
SI8400AB-B-ISR Visão geral
A digital isolator is an interface IC that transfers digital signals across an isolation barrier without any galvanic connection, replacing slower and less reliable optocoupler designs. Within the interface isolation hierarchy, it sits alongside RS-485, CAN, and SPI isolators as a key building block of industrial signal-chain design, protecting low-voltage microcontrollers from high-voltage domains.
Key features include true bidirectional I2C transfer on both SDA and SCL lines, 2500 Vrms isolation per UL-type testing, 25 kV/us typical CMTI for noisy industrial environments, and proprietary RF-coupled isolation technology that delivers short propagation delays and low power consumption compared with optocouplers.
The Si8400 architecture uses Skyworks proprietary RF isolation technology, which the manufacturer describes as offering shorter propagation delays, lower power consumption, smaller installed size, and more stable timing than optocoupler-based isolation. The two isolated channels each carry one I2C signal, and the -B suffix grade defines the speed and supply operating range of the device.
Typical applications include isolated I2C links to power supplies and battery-management systems, isolated SMBus in server and telecom equipment, industrial PLC analog-front-end isolation, and level-shifting between I2C voltage domains. The 2500 Vrms rating suits reinforced basic isolation for 230 VAC industrial systems.
A key design consideration is that I2C isolators draw dynamic supply current proportional to bus speed and capacitive loading; ensure adequate bypass capacitance on both VDD1 and VDD2 and keep the isolated-side ground return low-impedance to preserve signal integrity across the barrier.
This page synthesizes distributor pricing, drop-in alternative cross-references, design notes, and FAQ answers not found on the manufacturer product page.
Alternativas drop-in para SI8400AB-B-ISR — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
SI8400AB-B-IS
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
SI8405AB-B-ISR
✅ Drop-In ⚠️ Especificações não verificadas📋 Alternativa de referência (fora do catálogo)
SI8440AB-C-ISR
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
ADuM1200ARZ
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
ISO7420MDR
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
IL710-3E
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
SI8400AB-B-ISR Especificações
| Isolation Type | Digital Isolator (I2C/SMBus) |
| Number of Channels | 2 (bidirectional) |
| Isolation Voltage | 2500 Vrms |
| Common-Mode Transient Immunity | 25 kV/us (typ) |
| Interface | I2C, SMBus |
| Encapsulamento | 8-SOIC (0.154 in, 3.90 mm width) |
| Tipo de montagem | Surface Mount |
| Isolation Technology | RF coupling (proprietary) |
| Reel Packaging | Tape and Reel (-ISR suffix) |
Configuração de pinos do SI8400AB-B-ISR
| Pino 1 | GND1 — Side 1 ground reference |
| Pino 2 | SDA1 — Side 1 bidirectional I2C data |
| Pino 3 | SCL1 — Side 1 bidirectional I2C clock |
| Pino 4 | VDD1 — Side 1 supply voltage |
| Pino 5 | VDD2 — Side 2 supply voltage |
| Pino 6 | SCL2 — Side 2 bidirectional I2C clock |
| Pino 7 | SDA2 — Side 2 bidirectional I2C data |
| Pino 8 | GND2 — Side 2 ground reference |
Aplicações típicas
SI8400AB-B-ISR é adequado para 6 aplicaçãos: Isolated I2C Power Supply Supervision, Industrial PLC and Motor Drive Control, Server and Telecom SMBus Isolation, Medical Patient-Connected Equipment, Battery Management Systems, Smart Meters and Building Automation.
Isolated I2C Power Supply Supervision
The SI8400AB-B-ISR is commonly used to isolate the I2C/PMBus management link between a hot-swappable power supply or DC-DC module and its system controller. Its 2500 Vrms isolation matches basic insulation requirements for 230 VAC-class equipment, while the 25 kV/us CMTI tolerates the fast dv/dt transients generated by switching power stages near the management bus. Because both SDA and SCL channels are bidirectional, the two-wire protocol passes without external direction control or glue logic. Designers should budget bypass capacitance on both VDD domains and verify total bus capacitance stays within I2C limits after adding the isolator's propagation delay.
Recomendado
Industrial PLC and Motor Drive Control
In programmable logic controllers and motor drives, the SI8400AB-B-ISR isolates I2C-connected sensors and configuration peripherals from the noisy power domain. The 25 kV/us typical CMTI is essential beside IGBT and SiC inverter legs, where common-mode slew rates routinely exceed 10 kV/us and would corrupt optocoupler-based links. The RF-coupled isolation barrier delivers stable, short propagation delay so configuration registers and status reads remain deterministic. Its 8-SOIC footprint fits dense control cards, replacing bulkier multi-optocoupler I2C isolation circuits while reducing component count and quiescent power on both sides of the barrier.
Recomendado
Server and Telecom SMBus Isolation
Data-center power shelves and telecom rectifiers use SMBus (a derivative of I2C) for battery and PSU management, and the SI8400AB-B-ISR's explicit SMBus support makes it a natural fit. The 2500 Vrms rating isolates field-side battery strings from the low-voltage management plane, and the bidirectional channels transparently pass SMBus transactions including clock stretching and arbitration. Low dynamic supply current matters in always-on management planes where every milliwatt counts against shelf power budgets. Place the isolator at the connector side of the management card so the isolation barrier sits exactly where field wiring enters the system.
Recomendado
Medical Patient-Connected Equipment
Diagnostic and monitoring equipment that touches a patient requires galvanic isolation between patient-connected circuitry and powered electronics, and the SI8400AB-B-ISR provides a 2500 Vrms digital barrier for I2C-connected sensor front ends. Compared with optocoupler alternatives, Skyworks' RF isolation technology provides lower power consumption and more stable timing, which preserves measurement repeatability in multi-channel sensor arrays. The small 8-SOIC package allows isolation directly on the analog head board rather than at a central controller, shortening sensitive analog traces. Verify the system's applicable medical isolation standard before finalizing creepage and clearance design around the barrier.
Recomendado
Battery Management Systems
Battery-management systems stack many cell-monitoring ICs across large common-mode voltages, and the SI8400AB-B-ISR isolates the I2C management link between stacked monitor devices and the pack controller. The 25 kV/us CMTI handles the rapid common-mode shifts that occur during contactor switching and pre-charge events, which is precisely the transient regime where optocoupler-based two-wire links lose data. Its bidirectional channels support both configuration writes from the controller and alarm interrupts from the monitors without direction pins. Designers should keep the isolated-side supply locally regulated and decoupled to prevent pack transients from coupling into the logic supply pins.
Recomendado
Smart Meters and Building Automation
Smart electricity meters and building-automation gateways need an isolated I2C path between metering front ends referenced to mains and low-voltage communication processors. The SI8400AB-B-ISR's 2500 Vrms isolation addresses the basic insulation requirement of 230 VAC metering designs, while its 25 kV/us CMTI survives the burst transients typical of utility environments. Low quiescent consumption supports always-on metrology, and the 8-SOIC footprint fits the constrained layouts of meter PCBs. Because both channels are bidirectional, the same isolator also serves configuration traffic to the metering AFE during calibration at the factory, eliminating a second isolation component.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para SI8400AB-B-ISR — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | SI8400AB-B-IS | SI8405AB-B-ISR | ADuM1200ARZ | ISO7420MDR | IL710-3E |
|---|---|---|---|---|---|---|
| Package | 8-SOIC (3.90 mm) | 8-SOIC (3.90 mm) - same | 8-SOIC (3.90 mm) - same | 8-SOIC (3.90 mm) - same | 8-SOIC (3.90 mm) - same | 8-SOIC (3.90 mm) - same |
| Brand | Skyworks Solutions (Silicon Labs) | Skyworks Solutions | Skyworks Solutions | Analog Devices | Texas Instruments | NVE Corporation |
| Isolation Voltage | 2500 Vrms | 2500 Vrms | 5 kVrms class | 2500 Vrms | 2500 Vrms | 2500 Vrms |
| Number of Channels | 2 (bidirectional) | 2 (bidirectional) | 2 (bidirectional) | 2 (unidirectional) | 2 (unidirectional) | 1 (unidirectional) |
| Native I2C/SMBus Support | Yes | Yes | Yes | No (generic) | No (generic) | No (generic) |
| Packaging | Tape & Reel (-ISR) | Tube | Tape & Reel | Tape & Reel | Tape & Reel | Tape & Reel |
Principais diferenciais
- Native bidirectional I2C channels (vs ADuM1200ARZ)
- Higher isolation grade option in same footprint (vs SI8400AB-B-IS)
- Optocoupler-replacement architecture (vs IL710-3E)
Notas de projeto
Place 0.1 uF ceramic bypass capacitors within 2 mm of both VDD1 and VDD2 pins, each referenced to its own ground domain (GND1/GND2). Digital isolators draw dynamic current proportional to I2C speed and load capacitance, so an additional 4.7 uF bulk capacitor per side is recommended when driving long bus traces. Maintain the full creepage and clearance distance across the barrier - keep no copper or components under the SOIC-8 body between side-1 and side-2 pin groups, and route isolated traces with adequate spacing to the mounting plane.
I2C propagation delay through the isolator adds to total bus timing budget. At 400 kHz fast-mode, cumulative isolator delay plus rise times must still fit the I2C tHIGH/tLOW windows; verify timing at the highest planned bus speed with worst-case capacitive loading. Use pull-up resistors sized to both bus capacitance and the isolator input stage - lower values (2.2 to 4.7 kohm) improve edge rates on isolated sides. Keep SDA and SCL symmetric in length on the isolated side to minimize skew between the two channels.
Do not substitute general-purpose isolators such as ADuM1200 or ISO7420 directly for this part in an I2C design without redesign: their channels are unidirectional and will latch or corrupt bidirectional SDA traffic. Also note the -IS (tube) and -ISR (reel) suffixes are the same die but different delivery media - MSL handling per JESD22 still applies before reflow. Finally, confirm the continuous working voltage across the barrier meets your safety standard; 2500 Vrms is the withstand test rating, not the continuous working rating.
Informações de conformidade
Compliance statuses not stated in the retrieved distributor data; confirm RoHS/REACH status on the Skyworks product page or datasheet before export-critical designs.
