SI8660BB-B-IS1 - 6-Ch 2.5kV Digital Isolator, 150Mbps | Skyworks
MPN: SI8660BB-B-IS1 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.86 | $4.86 |
| 10 | $4.38 | $43.80 |
| 100 | $3.62 | $362.00 |
| 500 | $3.18 | $1,590.00 |
| 1,000 | $2.95 | $2,950.00 |
SI8660BB-B-IS1 Overview
A digital isolator is an integrated circuit that transfers logic signals across a galvanically isolated barrier using an internal high-frequency carrier (RF, magnetic, or optical) instead of optocouplers' slow LED-phototransistor path. It belongs to the hierarchy signal isolator -> isolator -> interface IC -> semiconductor. Compared to optocouplers, CMOS digital isolators deliver 10x to 100x faster data rates, 5x to 10x lower propagation delay, lower power consumption, tighter timing specifications, and better stability over temperature and device lifetime, while also eliminating the aging and CTR degradation inherent to LED-based isolators.
Key features include a fail-safe output (output default-high when input is unpowered), integrated power-on reset, 50 kV/µs transient immunity, 1.5 ns typical channel-to-channel skew, and 50 kV/µs ESD performance on the bus pins. The device supports 2.5 V, 3.3 V, and 5 V logic on each side independently, making it a flexible general-purpose isolator for SPI, I2C, GPIO, RS-485, and digital feedback paths.
Architecturally, the Si866x family uses an on-chip RF carrier modulated by the input data, transmitted across a high-voltage differential capacitive or transformer isolation barrier, then demodulated and re-timed on the secondary side. The internal oscillator and dual supply domains are referenced to separate grounds, enabling full galvanic isolation up to the rated working voltage. The six channels of the SI8660BB variant are partitioned as 0 forward / 6 reverse, suitable for uni-directional multi-channel signal return paths.
Typical applications include industrial fieldbus isolation (RS-485, CAN, Profibus), PLC and DCS I/O modules, isolated SPI/I2C interfaces between microcontrollers and ADCs, isolated gate-drive feedback in motor drives and solar inverters, isolated USB and Ethernet signal paths, and medical equipment patient-isolation barriers. The wide temperature range of -40°C to +125°C supports industrial and automotive-grade designs.
Design tip: place 0.1 µF bypass capacitors within 2 mm of each VDDA/VDDB pin and avoid routing high-speed traces directly under the SOIC body to minimize coupling to the ground plane. The default-high fail-safe output eliminates external pull resistors on the secondary side.
This page consolidates real-time distributor pricing, drop-in alternatives, design notes, and comparison tables that go beyond what the manufacturer datasheet alone provides for engineers evaluating the SI8660BB-B-IS1.
Drop-in alternatives for SI8660BB-B-IS1 — 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 SI8660BB-B-IS1 (same form factor and footprint) — differing in Package, Common-Mode Transient Immunity (CMTI), Data Rate, Operating Temperature, Technology.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
SI8661BB-B-IS1
✅ Drop-In📋 Reference alternative (not in catalog)
SI8662BB-B-IS1
✅ Drop-In✓ In Stock
$3.31 / Unit
View Datasheet →SI8663BB-B-IS1
✅ Drop-In📋 Reference alternative (not in catalog)
SI8660BB-B-IS1R
✅ Drop-In✓ In Stock
$2.78 / Unit
View Datasheet →SI8660BB-B-IU
✅ Drop-In📋 Reference alternative (not in catalog)
SI8660BB-B-IS1 Specifications
| Function | 6-channel digital isolator |
| Number of Channels | 6 |
| Channel Direction (Fwd/Rev) | 0 forward / 6 reverse |
| Isolation Rating | 2500 Vrms |
| Data Rate | 150 Mbps |
| Propagation Delay (typ) | 8 ns |
| Common-Mode Transient Immunity (min) | 35 kV/µs |
| Common-Mode Transient Immunity (typ) | 50 kV/µs |
| Supply Voltage (VDDA, VDDB) | 2.375 V to 5.5 V |
| Operating Temperature | -40 °C to +125 °C |
| Package | 16-pin SOIC (NSOIC, narrow body, 0.154", 3.90 mm) |
| Mounting Type | Surface Mount |
| Fail-Safe Output | Yes (default-high on unpowered input) |
| Power-On Reset | Yes (integrated) |
| Channel-to-Channel Skew (typ) | 1.5 ns |
| RoHS Status | Compliant |
SI8660BB-B-IS1 Pin Configuration
| Pin 1 | VDDA — Side A supply voltage (2.375 V to 5.5 V) |
| Pin 2 | OUTA0 — Side A output channel 0 (reverse-direction output) |
| Pin 3 | OUTA1 — Side A output channel 1 (reverse-direction output) |
| Pin 4 | OUTA2 — Side A output channel 2 (reverse-direction output) |
| Pin 5 | OUTA3 — Side A output channel 3 (reverse-direction output) |
| Pin 6 | OUTA4 — Side A output channel 4 (reverse-direction output) |
| Pin 7 | OUTA5 — Side A output channel 5 (reverse-direction output) |
| Pin 8 | GNDA — Side A ground reference |
| Pin 9 | GNDB — Side B ground reference (isolated from GNDA) |
| Pin 10 | INB5 — Side B input channel 5 (reverse-direction input) |
| Pin 11 | INB4 — Side B input channel 4 (reverse-direction input) |
| Pin 12 | INB3 — Side B input channel 3 (reverse-direction input) |
| Pin 13 | INB2 — Side B input channel 2 (reverse-direction input) |
| Pin 14 | INB1 — Side B input channel 1 (reverse-direction input) |
| Pin 15 | INB0 — Side B input channel 0 (reverse-direction input) |
| Pin 16 | VDDB — Side B supply voltage (2.375 V to 5.5 V) |
Typical Applications
SI8660BB-B-IS1 is suitable for 7 applications: Industrial RS-485 / CAN Fieldbus Isolation, Isolated SPI / I2C ADC Interface, Motor Drive Gate-Drive Feedback Isolation, Solar Inverter String Monitoring, Medical Patient-Isolation Interface, Isolated Industrial GPIO and PLC I/O Module, Isolated USB and Ethernet Data Path.
Industrial RS-485 / CAN Fieldbus Isolation
The SI8660BB-B-IS1 fits industrial fieldbus isolation because all six channels operate at 150 Mbps with 8 ns propagation delay and 35 kV/µs minimum CMTI, comfortably handling RS-485 (up to 50 Mbps) and CAN-FD signals with margin. The 2500 Vrms isolation barrier protects low-voltage MCUs from 24 V bus transients and ground-potential differences across long cable runs. Six reverse-direction channels naturally accommodate full-duplex return paths for transceiver enable, fault, and RX signals on the isolated side. Industrial PLC and DCS modules use this configuration to meet IEC 61800-3 surge and fast-transient requirements while the -40 to +125 °C operating range supports outdoor and unconditioned cabinet installations.
Recommended
Isolated SPI / I2C ADC Interface
The SI8660BB-B-IS1 is well suited for isolating multi-channel SPI or I2C communication between a controller and high-precision ADCs. With 150 Mbps data rate and 1.5 ns channel skew, the device preserves SPI clock-to-data timing margins across the isolation barrier, while the 8 ns propagation delay adds minimal latency to the data-acquisition loop. Its 2.375-5.5 V supply on both sides enables direct connection to 3.3 V MCUs and 5 V legacy ADCs without level shifters. Six reverse channels support SPI CLK, MOSI, MISO, CS, plus two DRDY or fault signals, all returning to the controller. The integrated fail-safe default-high output eliminates external pull resistors and simplifies BOM.
Recommended
Motor Drive Gate-Drive Feedback Isolation
The SI8660BB-B-IS1 fits motor-drive gate-driver feedback paths where six isolation channels are needed to return gate-drive fault, desaturation, and current-sense signals from the high-voltage inverter stage to the low-voltage control board. The 35 kV/µs minimum CMTI tolerates the high dV/dt noise from IGBT/MOSFET switching transitions without data corruption. With 8 ns propagation delay and 1.5 ns channel-to-channel skew, the device maintains accurate timing for synchronous rectification and overcurrent protection, which is critical for safety in industrial drives up to several kW. The 2500 Vrms isolation barrier provides basic isolation per IEC 61800-5-1 for 600 V and 1200 V drive systems when reinforced isolation is not required.
Recommended
Solar Inverter String Monitoring
The SI8660BB-B-IS1 is used in solar inverter string-monitoring modules to isolate the DC string-voltage measurement path from the inverter control board. Six reverse channels handle up to six string-current or voltage feedback signals simultaneously, while 150 Mbps bandwidth supports both slow analog-digitized data and high-speed digital status flags from monitoring ASICs. The 2500 Vrms rating covers 1500 V DC string-to-ground transients when paired with external TVS protection, and the industrial temperature range of -40 to +125 °C allows deployment in outdoor combiner boxes. The fail-safe output ensures the inverter safely enters a known state on power-up or fault events.
Recommended
Medical Patient-Isolation Interface
The SI8660BB-B-IS1 provides the 2500 Vrms basic isolation barrier required for patient-connected medical equipment such as patient monitors, infusion pumps, and ECG systems (per IEC 60601-1 2xMOPP at 2500 V requires reinforced isolation - the Si8660 provides basic isolation, suitable for 1xMOPP or signal-isolation portions). Six channels support isolated SPI to the analog front-end, plus isolated UART or USB data lines back to the host processor. The 8 ns propagation delay is far below the 10 µs latency budget for real-time vital-sign monitoring, and the integrated power-on reset ensures defined states on power-up. Combined with an isolated DC-DC converter, the Si8660BB enables creepage and clearance-compliant PCB layouts for patient-isolation boundaries.
Recommended
Isolated Industrial GPIO and PLC I/O Module
The SI8660BB-B-IS1 fits 24-channel-density PLC digital-input modules by stacking three Si8660 devices, each handling 6 isolated inputs returning to the backplane logic. With 150 Mbps bandwidth, the isolator easily handles 100 kHz typical PLC input scan rates, while the 35 kV/µs CMTI tolerates the inductive load switching noise from adjacent relay outputs. The 2.375-5.5 V supply range allows direct connection to 24 V field-side logic via external resistor dividers on the field side. Industrial certifications required for PLC I/O modules (UL 508, IEC 61131-2) leverage the part's wide operating temperature and robust isolation barrier, simplifying compliance documentation.
Recommended
Isolated USB and Ethernet Data Path
The SI8660BB-B-IS1 is used in industrial USB and Ethernet isolators where the host-side controller and the cable-side bus require 2500 Vrms isolation for surge and ground-loop protection. Six reverse channels accommodate USB D+/D-, VBUS-sense, and Ethernet RX/TX pairs in a single device, while 150 Mbps bandwidth exceeds USB Full Speed (12 Mbps) and 10/100 Ethernet (100 Mbps) requirements with substantial margin. The 8 ns propagation delay adds negligible latency for transparent USB or Ethernet bridging, and the integrated fail-safe output prevents bus lockup when the host or device is unpowered. The NSOIC-16 package fits compact dongle-style isolator designs.
Recommended
Recommended Products Summary
Engineering reference data for SI8660BB-B-IS1 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | SI8661BB-B-IS1 | SI8662BB-B-IS1 | SI8663BB-B-IS1 | SI8660BB-B-IS1R | SI8660BB-B-IU |
|---|---|---|---|---|---|---|
| Brand | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions | Skyworks Solutions |
| Package | 16-SOIC (NSOIC, narrow body) | 16-SOIC (NSOIC, narrow body) - same | 16-SOIC (NSOIC, narrow body) - same | 16-SOIC (NSOIC, narrow body) - same | 16-SOIC (NSOIC, narrow body) - same | 16-SSOP (narrow body) |
| Number of Channels | 6 | 6 | 6 | 6 | 6 | 6 |
| Channel Direction (Fwd/Rev) | 0 / 6 | 1 / 5 | 2 / 4 | 3 / 3 | 0 / 6 (same) | 0 / 6 (same) |
| Isolation Voltage | 2500 Vrms | 2500 Vrms | 2500 Vrms | 2500 Vrms | 2500 Vrms | 2500 Vrms |
| Data Rate (max) | 150 Mbps | 150 Mbps | 150 Mbps | 150 Mbps | 150 Mbps | 150 Mbps |
| Propagation Delay (typ) | 8 ns | 8 ns | 8 ns | 8 ns | 8 ns | 8 ns |
| CMTI (min) | 35 kV/µs | 35 kV/µs | 35 kV/µs | 35 kV/µs | 35 kV/µs | 35 kV/µs |
| Fail-Safe Output | Yes | Yes | Yes | Yes | Yes | Yes |
Key Differentiators
- Highest channel count in 2.5 kVrms narrow-body SOIC-16 family (vs SI8640BB-B-IS (4-channel alternative in same family))
- 150 Mbps per-channel data rate with 35 kV/µs CMTI (vs Generic 1 Mbps optocoupler designs (e.g., 6N137 quad optoisolator stacks))
- Integrated fail-safe default-high output (vs TI ISO6741 (4-channel, 50 kV/µs))
Design Notes
Place 0.1 µF low-ESR ceramic bypass capacitors within 2 mm of each VDDA (pin 1) and VDDB (pin 16) pin. For multi-channel operation at maximum 150 Mbps data rate, add a 1 µF bulk capacitor on each supply side to handle transient current demand during simultaneous channel switching. The 2.375-5.5 V supply range allows direct connection to 3.3 V or 5 V rails without additional level shifters. Power-on reset is integrated; no external POR capacitor is required.
Maintain at least 4 mm clearance between the SI8660BB-B-IS1 and any copper trace or plane on either side of the isolation barrier to preserve the 2500 Vrms rating and meet IEC 60747-17 creepage/clearance requirements. Avoid routing high-speed signals directly beneath the SOIC body; route only low-speed signals or keep-out zones in the inner layers under the part. The exposed paddle is internally connected to GNDA on the A-side; do NOT connect the paddle to GNDB, as this would defeat the galvanic isolation.
For 150 Mbps operation, source-terminate each channel with a series resistor (typically 22-33 Ω) close to the driver to control reflections on the input side. The 8 ns propagation delay and 1.5 ns channel skew are specified at 50% Vdd thresholds with 15 pF load; verify timing margins in your actual load conditions, especially for clock-forwarded protocols like SPI where setup/hold times degrade with additional capacitive loading on the receiver side. Maintain tight return paths and avoid splitting ground planes across the isolation barrier.
Do NOT use the SI8660BB-B-IS1 in applications requiring reinforced isolation (e.g., 5 kVrms medical or 8 mm creepage for 690 V drives); use the Si8660T wide-body variant instead for 5 kVrms. Do NOT assume all 6 channels can operate at 150 Mbps simultaneously without verifying thermal performance - worst-case power dissipation can reach 250 mW at full load, requiring the SOIC-16 thermal pad to be soldered to a sufficient copper pour (≥100 mm² recommended) on each side.
Compliance Information
RoHS compliant per Skyworks product page. Industrial -40 to +125 °C temperature grade. Not AEC-Q100 qualified; for automotive isolation needs, refer to Skyworks' automotive-graded Si86xx variants.
