Digital Isolators

Part Number	Description / PDF	Quantity
SI8421BB-C-ISR Silicon Labs	DIGITAL ISOLATOR 2CH 5.5V 8SOIC	0
SI82305B-D-IS1R Silicon Labs	DIGITAL ISOLATOR	0
SI8645BA-C-IU Silicon Labs	DIGITAL ISOLATOR	0
SI8431BB-C-ISR Silicon Labs	IC ISOLATOR 3CH 5.5V 16-SOIC	0
SI83404AAA-IFR Silicon Labs	DGTL ISOL 1500VRMS 4CH SPI 32DFN	0
SI88343BD-IS Silicon Labs	IC DIGITAL ISOLATOR SOIC	0
SI8610BB-B-IM1 Silicon Labs	2.5KV SINGLE CHANNEL ISOLATOR IN	86
SI8421AB-C-ISR Silicon Labs	DIGITAL ISOLATOR 2CH 5.5V 8SOIC	0
SI83402AAA-IF Silicon Labs	DGTL ISOL 1500VRMS 4CH SPI 32DFN	0
SI8441BB-C-ISR Silicon Labs	IC DIGITAL ISOLATOR SOIC	0
SI8621BB-B-IM1 Silicon Labs	2.5KV DUAL CHANNEL ISOLATOR IN C	50
SI88340BD-IS Silicon Labs	IC DIGITAL ISOLATOR SOIC	0
SI83401ABA-IFR Silicon Labs	DGTL ISOL 1500VRMS 4CH SPI 32DFN	0
SI8645BA-B-IS1 Silicon Labs	DIGITAL ISOLATOR	0
SI8410BB-C-ISR Silicon Labs	IC ISOLATOR 1CH 5.5V 8-SOIC	0
SI8610EB-B-IM1 Silicon Labs	2.5KV SINGLE CHANNEL ISOLATOR IN	71
SI88341BD-ISR Silicon Labs	IC DIGITAL ISOLATOR SOIC	0
SI88442BD-IS Silicon Labs	IC DGTL ISO 5KV 4CH GP 20SOIC	0
SI83418ADA-IF Silicon Labs	DGTL ISOL 1500VRMS 4CH SPI 32DFN	276
SI8620BB-B-IM1R Silicon Labs	2.5KV DUAL CHANNEL ISOLATOR IN C	0

Digital Isolators

1. Overview

Digital isolators are electronic components that enable signal transmission between circuits or systems with different voltage levels while maintaining electrical isolation. They utilize semiconductor technologies (e.g., capacitive, inductive, or optical coupling) to replace traditional optocouplers. These devices are critical in modern systems for ensuring safety, reducing noise interference, and enabling communication in high-voltage environments.

2. Main Types and Functional Classification

Type	Functional Features	Application Examples
Capacitive Isolators	Use high-frequency capacitive coupling for signal transfer. Low power consumption, supports high data rates.	Industrial motor drives, PLC systems
Inductive (Magnetic) Isolators	Utilize miniature transformers for isolation. High noise immunity, supports bidirectional communication.	Automotive BMS, battery chargers
Optocoupler-Based Digital Isolators	Hybrid design combining LED and CMOS detectors. Low cost, moderate speed.	Consumer electronics, home appliances
Multi-Channel Isolators	Integrate multiple isolation channels in one package. Supports complex signal routing.	Data acquisition systems, industrial IoT gateways

3. Structure and Components

A typical digital isolator consists of: (1) Input circuit with signal conditioning; (2) Isolation barrier (e.g., SiO2 capacitive layer or micro-transformer core); (3) Output circuit with amplification/reconstruction; (4) Dual-die packaging with reinforced insulation. Advanced products integrate signal and power isolation in single chips.

4. Key Technical Specifications

Parameter	Unit	Importance
Isolation Voltage (Viso)	Vrms	Determines safety level (e.g., 2500-5000Vrms for industrial use)
Data Rate	Mbps	Defines maximum signal transmission speed (1-150 Mbps)
Propagation Delay	ns	Impacts system timing accuracy (Typ. 10-50 ns)
Power Consumption	mW	Crucial for battery-powered devices
Operating Temperature	C	Specifies environmental tolerance (-40 to +125 C)

5. Application Fields

Industrial automation (PLC, motor drives)
Medical equipment (ECG machines, patient monitors)
Automotive systems (BMS, OBC for EVs)
Renewable energy (solar inverters, grid-tied systems)
Telecommunications (5G base stations, optical transceivers)

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Specifications
Analog Devices	ADN4654	150Mbps, 5kVrms isolation, 4-channel
Texas Instruments	ISO7841	100Mbps, 8kV CMTI, quad-channel
Silicon Labs	SI8640	150Mbps, 2.5kVrms, 4-channel
Infineon	BDx183	100Mbps, reinforced isolation, automotive-grade

7. Selection Guidelines

Define isolation voltage and safety certification (e.g., UL, VDE)
Match data rate with system requirements
Consider channel count and directionality
Evaluate power budget and PCB space constraints
Check environmental specifications (temperature, vibration)

8. Industry Trends

Future development focuses on: (1) Integration of isolation and level-shifting functions; (2) 3D packaging for miniaturization; (3) Enhanced immunity to electromagnetic interference (EMI < 150 V/m); (4) System-level isolation solutions combining signal/power transfer. The market is projected to grow at 12% CAGR until 2028, driven by EV and industrial IoT adoption.

Application Case

In electric vehicles, digital isolators like TI's ISO7741 are used in battery management systems to isolate high-voltage battery packs (up to 1000V) from low-voltage control circuits, enabling safe CAN bus communication with 50kV/ s common-mode transient immunity (CMTI).