Analog Devices launches small isolated gate drivers for SiC and GaN power switch technology

2017-05-23

Analog Devices Inc (ADI) of Norwood, MA, USA has launched small-form-factor isolated gate drivers designed for the higher switching speeds and system size constraints required by power switch technologies such as silicon carbide (SiC) and gallium nitride (GaN), while still providing reliable control over switching characteristics for insulated-gate bipolar transistor (IGBT) and metal-oxide-semiconductor field-effect transistor (MOSFET) configurations. The ADuM4120 and ADuM4121 series leverages ADI’s proven iCoupler isolation technology combined with high-speed CMOS and monolithic transformer technology to enable ultra-low propagation delay without sacrificing common mode transient immunity (CMTI) performance.

While legacy alternatives such as optocouplers or pulse transformers struggle to deliver shorter delay and maintain CMTI performance, the robust ADuM4120 and ADuM4121 are designed to enable the higher switching speeds of the new inverter architectures, says ADI. In systems requiring multiple power switches, the small SOIC packaged isolated gate drivers minimize PCB layout space, subsequently reducing cooling requirements. Additionally, their small size allows the gate drivers to be located close to the power switches to reduce the parasitic inductance between the driver and the switch. Operating over a high temperature range and high working voltages, the ADuM4120 and ADuM4121 are suitable for improving the energy efficiency and timing performance stability of solar inverters, motor controllers, and industrial inverter applications, says ADI.

All four devices in the new series are 2A output, single-channel gate drivers that provide 5kV rms isolation with low propagation delay and CMTI performance of >150kV/μs. Operating with an input supply ranging from 2.5V to 6.5V, the isolated gate drivers provide compatibility with lower-voltage systems with the benefit of true galvanic isolation between the input and the output.

The ADuM4120 and ADuM4120-1 (each supplied in a 6-lead SOIC package, and priced at $1.58 in 1000-unit quantities) provide thermal shutdown for over-temperature protection. The ADuM4120 (with input glitch filter) reduces system noise on the input pin that could trigger a false output, while the ADuM4120-1 (without glitch filter) supports low 33ns typical propagation delay. The ADuM4121 and ADuM4121-1 (each supplied in an 8-lead SOIC package, and priced at $1.87 in 1000-unit quantities) are available with an internal Miller clamp for added protection. The ADuM4121 device is also available with the thermal shutdown.

ADI says that, by offering gate drivers in a small package and retaining key performance specifications, it provides designers with the flexibility needed to architect next-generation power conversion systems.