SI8600AB-B-ISR - 2.5kV I2C Digital Isolator, 8-SOIC | Skyworks/Silicon Labs
MPN: SI8600AB-B-ISR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.33 | $2.33 |
| 10 | $2.1 | $21.00 |
| 100 | $1.86 | $186.00 |
| 500 | $1.62 | $810.00 |
| 1,000 | $1.4 | $1,400.00 |
| 3,000 | $1.18 | $3,540.00 |
SI8600AB-B-ISR Overview
A digital isolator is a semiconductor device that transmits data across an electrical isolation barrier using capacitive, magnetic, or RF coupling instead of optocouplers. Compared to optocouplers, RF-coupled isolators such as the SI8600 deliver faster propagation delay (typically 20 ns), dramatically lower power consumption, and stable parametric behavior over temperature and aging. Digital isolators are the modern building block of functional-isolation signal chains in industrial I2C buses, where they break ground loops while preserving bidirectional handshake semantics.
Key features include two bidirectional channels with open-drain, 35 mA sink capability, hot-swap tolerant inputs that tolerate bus contention during plug-in, clock-stretching support, and Schmitt-triggered inputs with typical 20 ns propagation delay. The 8-SOIC package footprint is the industry-standard digital-isolator outline, and the device requires no external clock or configuration components.
Internally the SI8600AB-B-ISR uses Silicon Labs' proprietary RF isolation technology, transmitting edge transitions across a polyimide insulation region using an on-chip RF carrier. This topology yields >25 years of insulation lifetime at rated working voltage, deterministic propagation delay, and >50 kV/µs transient immunity that exceeds optocoupler performance by an order of magnitude.
Typical applications include isolated I2C bus interfaces between a microcontroller and a sensor front-end, hot-swappable I2C peripherals in telecom equipment, SMBus isolation in server backplanes, industrial I/O modules with functional isolation, and any 4-wire bidirectional I2C/SMBus link requiring reinforced safety isolation.
A key design consideration is that both sides of the SI8600AB-B-ISR require their own bypass capacitor (typically 0.1 µF ceramic close to VDD pins) and pull-up resistors sized for the chosen I2C speed. The device supports standard-mode (100 kHz), fast-mode (400 kHz), and fast-mode-plus (1 MHz) I2C; for 1.7 MHz operation consult the datasheet.
This page consolidates distributor pricing, drop-in alternatives including the TI ISO1640 pin-to-pin replacement, and practical PCB and hot-swap design notes that go beyond the manufacturer datasheet narrative.
Drop-in alternatives for SI8600AB-B-ISR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with SI8600AB-B-ISR (same form factor and footprint) — differing in Package, RoHS Status, Common-Mode Transient Immunity (CMTI), Hot-Swap Support, Number of Channels.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
SI8600AB-B-IS
✅ Drop-In✓ In Stock
$3.95 / Unit
View Datasheet →SI8600AC-B-ISR
✅ Drop-In📋 Reference alternative (not in catalog)
SI8602AB-B-ISR
✅ Drop-In📋 Reference alternative (not in catalog)
SI8600AB-B-ISR-Q1
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ISO1640BDR
✅ Drop-In✓ In Stock
$2.05 / Unit
View Datasheet →ISO1640-Q1
✅ Drop-In📋 Reference alternative (not in catalog)
SI8600AB-B-ISR Specifications
| Function | Bidirectional I2C Digital Isolator |
| Channels | 2 bidirectional (SDA + SCL) |
| Isolation Voltage (rms) | 2500 Vrms |
| Common-Mode Transient Immunity (CMTI) | 35 kV/µs (min) |
| Data Rate (max) | 1.7 MHz |
| Propagation Delay (typ) | 20 ns |
| Supply Voltage (both sides) | 3 V to 5.5 V |
| Output Type | Open-drain, 35 mA sink capability |
| Hot-Swap Tolerant | Yes |
| Clock Stretching Support | Yes |
| Operating Temperature | -40 C to +125 C |
| Package | 8-SOIC (0.154 inch / 3.90 mm width) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
SI8600AB-B-ISR Pin Configuration
| Pin 1 | VDD1 — Side 1 supply voltage (3 V to 5.5 V) |
| Pin 2 | GND1 — Side 1 ground (isolated from GND2) |
| Pin 3 | SDA1 — Bidirectional serial data, side 1 (open-drain, 35 mA sink) |
| Pin 4 | SCL1 — Bidirectional serial clock, side 1 (open-drain, 35 mA sink) |
| Pin 5 | SCL2 — Bidirectional serial clock, side 2 (open-drain, 35 mA sink) |
| Pin 6 | SDA2 — Bidirectional serial data, side 2 (open-drain, 35 mA sink) |
| Pin 7 | GND2 — Side 2 ground (isolated from GND1) |
| Pin 8 | VDD2 — Side 2 supply voltage (3 V to 5.5 V) |
Typical Applications
SI8600AB-B-ISR is suitable for 6 applications: Industrial I2C Bus Isolation in PLC Backplanes, Hot-Swappable SMBus Peripherals in Telecom Equipment, Isolated Battery-Management I2C Interface (BMS), Isolated Sensor Front-End Interface, Medical Equipment I2C Isolation (Patient-Connected Devices), LED Display Panel I2C Multidrop Isolation.
Industrial I2C Bus Isolation in PLC Backplanes
The SI8600AB-B-ISR provides 2500 Vrms functional isolation between a PLC CPU and remote I/O modules on a 24 V industrial backplane where ground-potential differences and switching transients would otherwise corrupt the I2C link. The 35 kV/us minimum CMTI tolerates the fast dV/dt events common on 24 V motor-drive and solenoid buses, while the bidirectional SDA and SCL channels preserve the standard I2C handshake including clock stretching. Both sides operate from 3 V to 5.5 V, letting engineers derive isolated 3.3 V rails from the 24 V bulk. The -40 C to +125 C operating range covers factory-floor environmental requirements.
Recommended
Hot-Swappable SMBus Peripherals in Telecom Equipment
The SI8600AB-B-ISR is purpose-built for hot-swappable SMBus peripheral cards in telecom and server backplanes where bus contention during insertion is unavoidable. The device's hot-swap tolerant inputs prevent back-powering and bus contention while the open-drain 35 mA sink drivers deliver clean low-side transitions. The 1.7 MHz maximum data rate covers all standard SMBus speeds including fast-mode-plus, while the 20 ns typical propagation delay keeps the bus within SMBus timing budgets. The 8-SOIC footprint is the industry-standard digital-isolator outline, simplifying second-source qualification.
Recommended
Isolated Battery-Management I2C Interface (BMS)
The SI8600AB-B-ISR is widely used in lithium-ion battery-management systems (BMS) to isolate the I2C link between the host microcontroller and the high-side cell-monitoring AFE, where common-mode voltages can exceed 60 V and ground loops would degrade coulomb-counting accuracy. The 2500 Vrms rating provides basic isolation suitable for 12 V to 48 V battery packs, and the bidirectional SDA/SCL pass-through preserves SMBus alert response. The 20 ns propagation delay does not perturb the host's cell-balancing control loop, and the 35 mA sink capability easily drives long bus cables to remote AFEs.
Recommended
Isolated Sensor Front-End Interface
The SI8600AB-B-ISR provides the I2C isolation barrier between a microcontroller and an isolated sensor front-end (e.g. digital temperature, pressure, or gas sensor) where the sensor must operate at a different ground potential. The two bidirectional channels carry SDA and SCL while preserving the standard I2C ACK/NACK semantics and clock stretching. The 3 V to 5.5 V supply range on both sides lets the sensor module use its own low-noise LDO without cross-side dependency. With 35 kV/us CMTI, the device withstands ESD and EFT events common near analog sensors.
Recommended
Medical Equipment I2C Isolation (Patient-Connected Devices)
The SI8600AB-B-ISR provides 2500 Vrms functional isolation between patient-connected medical sensors and the host controller in patient-monitoring devices where patient leakage currents must be limited per IEC 60601-1. The device's two bidirectional channels carry SDA and SCL between the isolated sensor front-end and the display/processor unit. The 20 ns propagation delay supports real-time vital-signs monitoring, while the 1.7 MHz enable enables PMBus-style battery telemetry on portable carts. Always verify system-level IEC 60601-1 compliance with a certified isolation barrier; the SI8600 is one component of that system.
Recommended
LED Display Panel I2C Multidrop Isolation
The SI8600AB-B-ISR is used inside large-format LED video walls and signage panels to isolate the I2C link between the controller and each individual LED-driver card over hundreds of feet of bus cable. The 35 mA sink capability and 1.7 MHz enable the bus to drive long capacitive chains, and the 35 kV/us CMTI rejects the high dV/dt from PWM dimming on the LED strings. The bidirectional SDA/SCL preserves display-config writes, while the 8-SOIC footprint makes it easy to place close to each connector on a multi-card backplane.
Recommended
Recommended Products Summary
Engineering reference data for SI8600AB-B-ISR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | SI8600AB-B-IS | SI8600AC-B-ISR | SI8602AB-B-ISR | ISO1640 | ISO1640-Q1 |
|---|---|---|---|---|---|---|
| Brand | Skyworks Solutions (formerly Silicon Labs) | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions | Texas Instruments | Texas Instruments |
| 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 (D) - same | 8-SOIC (D) - same |
| Isolation Voltage | 2500 Vrms | 2500 Vrms | 2500 Vrms | 2500 Vrms | 2500 Vrms | 2500 Vrms |
| Max Data Rate | 1.7 MHz | 1.7 MHz | 1.7 MHz | 1.7 MHz | 1.7 MHz | 1.7 MHz |
| Channels | 2 bidirectional (SDA + SCL) | 2 bidirectional | 2 bidirectional | 1 bidi SDA + 1 unidi SCL | 2 bidirectional | 2 bidirectional |
| Supply Voltage | 3 V to 5.5 V (both sides) | 3 V to 5.5 V | AC variant (see datasheet) | 3 V to 5.5 V | Side 1: 3-5.5V; Side 2: 2.25-5.5V | Side 1: 3-5.5V; Side 2: 2.25-5.5V |
| Automotive Grade | No | No | No | No | No | Yes (AEC-Q100) |
Key Differentiators
- Native bidirectional I2C in 8 pins without external direction logic (vs Generic optocoupler + buffer solution)
- 35 kV/µs minimum CMTI - 7x better than typical optocouplers (vs Optocoupler-based I2C isolator (e.g. discrete HCPL-0723 + I2C buffer))
- TI ISO1640 cross-brand drop-in replacement available (vs ISO1640 (Texas Instruments))
Design Notes
Both sides of the SI8600AB-B-ISR require their own local bypass capacitor - typically 0.1 µF X7R ceramic placed within 2 mm of the VDD1 and VDD2 pins. Each side must be powered from a supply referenced to its own ground (GND1 and GND2 are isolated; do not connect them). For industrial 24 V systems, derive isolated 3.3 V or 5 V rails with a small isolated DC-DC converter (1 W is typically enough because the Si860x draws <10 mA on each rail). Star-ground the VDD return to the bypass cap's ground pad to suppress switching noise.
The 8-SOIC SI8600AB-B-ISR requires no special PCB layout beyond the standard digital-isolator footprint. Maintain at least 4 mm of clearance between side-1 and side-2 copper to preserve 2500 Vrms isolation; do not route any side-1 trace under the package body. Place pull-up resistors close to the SDA/SCL pins on each side, sized between 2.2 kohm (fast mode) and 10 kohm (standard mode) depending on bus capacitance. The exposed pad (if present in some variants) is not internally connected - leave it floating or tied to the side-1 ground, never to side-2 ground.
Do not cross-connect VDD1 and VDD2 grounds - doing so destroys the isolation barrier and defeats the purpose of the device. The SI8600AB-B-ISR is not a galvanic isolator for power, only for signals - do not attempt to power side 2 from side 1 through the isolation barrier. Do not pull SDA/SCL above VDD or below ground on either side, as the open-drain outputs are only rated to VDD. For bidirectional I2C, both lines need pull-ups on each side - omitting the side-2 pull-ups is the most common reason for read failures on isolated buses.
Compliance Information
RoHS compliant per JLCPCB and Heisener listings. Standard grade only - choose SI8600AB-B-ISR-Q1 for AEC-Q100 automotive. UL 1577 recognized at 2500 Vrms basic insulation per Skyworks datasheet.
