Silicon Labs Grows its Offerings of Isolated Gate Drivers

The new gate drivers enable designers to drive modern SiCs, GaNs and fast Si FETs while increasing energy efficiency and saving precious board space

 

Si825xx 4 Amp Symmetric Drivers. Image courtesy of Silicon Labs

 

The units provide high 4 amps of sink/source current for faster FET turn on and to reduce switching losses. They cut latency in half with a maximum propagation delay of 30 ns, reducing the feedback loop delay, resulting in greater system efficiency. Because they are aimed at operation in electrically noisy environments, these isolated gate drivers feature augmented transient noise immunity. 

• Maximum supply voltage is 30 volts. 
• All units feature over-temperature protection and output UVLO fault detection
• All units are AEC-Q100 qualified
• Common mode transient immunity (CMTI) is 125 kV/μs. 
• They can accommodate up to 1500 VDC peak driver-to-driver differential voltage

 

Functional Description

The Si823Hx/825xx family differs from optocoupler gate drivers in that an RF carrier is modulated instead of light to provide isolation.

 

Image used courtesy of Data Sheet

 

This arrangement results in low power consumption and better immunity to electronic noise and stray magnetic fields

 

Si825xx

There are six members of the Si825xx grouping, all of them new. They are listed HERE.

 

Variations of the Si8252x. Modified image used courtesy of  Si8252x Data Sheet 

 

Members of this group offer two isolated drivers in one package. They feature an input voltage range of 4.5 to 20 Volts, enabling them to directly interface with analog controllers’ power rails. 

They support up to 5 kVRMS isolation voltage for 1 minute.

Dead-time is programmable over a 40 – 600 ns range.

 

Si823Hx 

There are 69 members of this family, not quite half of which are new. The complete listing is, HERE, with links to in-depth information about each specific device. There is also a detailed Data Sheet. 

These units feature single or two isolated drivers in one package with options for 2.5 kVrms and 3.75 kVrms isolation.

Dead-time is programmable dead time over 20 to 200 ns.

This group can operate with a 3.0 – 5.5 volt input VDD 

As per Brian Mirkin, vice president and general manager of Power Products at Silicon Labs. “Power converter designers in the automotive, industrial and renewable energy markets are managing a dynamic environment with emerging energy efficiency standards and new technology options, while also meeting continued demands for both safety and power.” He goes on to say that “Our new isolated gate drivers deliver the high-performance capabilities power engineers need to meet and exceed industry requirements, including an extended input voltage range, lower latency, high noise immunity, and rapid switching abilities.”

 

Getting to Market Faster 

Silicon Labs offer the Si82520-KIT evaluation board for the SI8252x family and the Si823H2-KIT evaluation board for the Si823H2 group

 

The Si823H2-Kit. Image used courtesy of Silicon Labs

 

Both boards enable quick evaluation of their respective devices and they enable direct connection to the designer’s end system. 

 

Applications

Silicon Labs’ isolated gate drivers can be applied to a broad range of power applications including:

• Data center power supplies 
• Micro inverters used in solar power applications
• Industrial power supplies. 
• Automotive market traction inverters
• Motor control
• Lightning controllers
• Isolated power supplies

 

Pending Safety Approvals include 

• UL 1577 
• CSA certification conformity
• VDE certification conformity
• CQC certification approval 

 

Physical Consideration

These devices operate over a temperature range of –40 to +125 °C

All are available in RoHS-compliant packages