Low-side gate driver enables high efficiency and power density

Texas Instruments Inc. announces a low-side gate driver for use with MOSFETs and Gallium-Nitride (GaN) power field-effect transistors (FETs) in high-density power converters. The new LM5114 drives GaN FETs and MOSFETs in low-side applications, such as synchronous rectifiers and power factor converters.

Together with the LM5113, a 100-V half-bridge GaN FET driver announced in 2011, the family provides a complete isolated dc-dc conversion driver solution for high-power GaN FETs and MOSFETs used in high-performance telecom, networking, and data center applications.

The LM5114 drives both standard MOSFETs and GaN FETs by using independent sink and source outputs from a 5-V supply voltage. It features a high 7.6-A peak turn-off current capability needed in high-power applications where larger or paralleled FETs are used. The increased pull-down strength also enables it to properly drive GaN FETs. The independent source and sink outputs eliminate the need for a diode in the driver path and allow tight control of the rise and fall times.

Key features and benefits of the LM5114 low-side gate driver:

• Independent source and sink outputs for optimized rise and fall times enable higher efficiency
• 4 to 12.6-V single power supply supports a wide range of applications
• 0.23-Ohm open-drain, pull-down, sink output prevents unintended turn-on
• 7.6-A/1.3-A peak sink/source driver current maximizes change-in-voltage over change-in-time (DV/DT) immunity
• Matching delay time between inverting and non-inverting inputs reduces dead time losses
• 12-ns typical propagation delay enables high switching frequency while maintaining improved efficiency
• Up to 14-V logic inputs, regardless of VCC
• -40° to 125° C operating temperature range