Digital Isolators

Digital isolators are electronic components that transmit signals through optical, magnetic, or capacitive coupling technologies. They provide electrical isolation between systems with different voltages or grounds, ensuring data accuracy and system security.

1. What are the Core Functions of Digital Isolators?

Electrical Isolation and Safety Protection

Isolating high- and low-voltage circuits, they prevent damage from power supply fluctuations and electrostatic discharge (ESD) to low-voltage circuits, with an isolation voltage of up to 5000 VRMS.

Interference Immunity

Suppresses electromagnetic interference (EMI) and noise, ensuring signal stability, with a typical common-mode transient immunity (CMTI) of ±100 kV/μs.

High-Speed Signal Transmission

Supporting data rates of 100 Mbps to 150 Mbps, far exceeding traditional optocouplers, they are suitable for real-time control systems.

2. What are the Types and Principles of Digital Isolators?

Type	Working Principle	Features
Optocoupler Isolation	Input electrical signal → LED light signal → Photodetector → Output electrical signal.	Low cost, long lifespan; slow speed (<50 Mbps).
Magnetic Isolation	Signal transmission via magnetic field coupling, achieved through a transformer or inductor.	Long transmission distance; large size, weak resistance to magnetic interference.
Capacitive Isolation	Capacitive coupling technology with internal AC/DC dual-channel intelligent switching.	Excellent high-frequency performance (150 Mbps), low power consumption, and strong EMI immunity.

 

3. What are the Key Application Scenarios of Digital Isolators?

1) Smart Home and Industrial Control: Isolates sensor and actuator signals, preventing ground loop interference and improving device reliability.

2) New Energy Vehicles and Autonomous Driving:

Battery Management System (BMS): Ensures secure communication between high-voltage batteries and low-voltage control circuits.

Motor Drive: Ensures delay-free transmission of power signals in traction inverters to prevent latch-up effects.

3) Medical and Power Systems: Isolates patient circuits in devices such as electrocardiographs, enabling high-precision current/voltage measurement in power monitoring.

4. Technology Evolution Trends of Digital Isolators

Integrated Design: Multi-channel isolators reduce external components and optimize PCB layout.

Wireless Signal Isolation: New solutions (such as Silicon Labs’ products) replace physical media with 2.4 GHz RF transmission, offering lower power consumption and higher speeds.

Improved Reliability: Capacitive isolators address power-on surge issues and ensure correct signal polarity.

Digital isolators are driving innovation in high-safety electronic systems, becoming a key enabling technology in autonomous driving, Industry 4.0, and energy sectors.