All power stage designers like to see a perfect square waveform at the switch-node. Fast rising/falling edge reduces switching losses, and low overshoot and ringing minimizes voltage stresses on the power FETs.
Designed with TI’s latest GaN technology, the power stage’s switch-node waveform shown in Figure 1a, looks truly impressive, from 0V to 480V at a 120V/ns slew rate, with less than 50V overshoot.
GaN FETs have low terminal capacitance, and thus enable fast switching. When a GaN half bridge switches at high di/dt, however, the power-loop inductance introduces ringing/overshoot at the high-voltage bus and switch node. This limits how fast the GaN FETs can switch.
Traditional power packages often have high inductance from both leads and bond wires due to long leads and large package sizes. Overshoots as high as a few hundred volts have been observed with leaded packages. The key to reducing overshoot is to minimize the power-loop inductance.
To reduce lead inductance, TI offers its single channel GaN power stage products in surface-mount quad flat no-lead (QFN) packages. As shown in Figure 1b, TI designs the power loops and gate loops to have low inductance internal to the QFN. TI’s GaN half-bridge evaluation module (EVM), shown in Figure 1c places the high and low side devices and bus capacitors close together and returns the power loop at the board layer immediately underneath the devices. This minimizes the size of the power loop, thus keeping the loop inductance low.
TI’s advanced packaging and board design reduces the power-loop inductance to a few nano-Henries. This low-inductance design, integrated with an optimized driver, enables the LMG3410 to switch at slew rates >100V/ns with less than 10% overshoot. With the LMG3410, you can design power converters to switch fast for better efficiency, with low-voltage overshoots and reduced electromagnetic interference (EMI).
TI’s LMG3410 GaN power stage enables power-supply designers to develop higher-density and higher-efficiency power supplies. The device’s ability to reliably switch at high slew rates, combined with an integrated driver with over-current and over-temperature protections, simplifies your job of developing industry-leading power solutions.
TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING REFERENCE DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS” AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY RIGHTS.
These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable standards, and any other safety, security, or other requirements. These resources are subject to change without notice. TI grants you permission to use these resources only for development of an application that uses the TI products described in the resource. Other reproduction and display of these resources is prohibited. No license is granted to any other TI intellectual property right or to any third party intellectual property right. TI disclaims responsibility for, and you will fully indemnify TI and its representatives against, any claims, damages, costs, losses, and liabilities arising out of your use of these resources.
TI’s products are provided subject to TI’s Terms of Sale (www.ti.com/legal/termsofsale.html) or other applicable terms available either on ti.com or provided in conjunction with such TI products. TI’s provision of these resources does not expand or otherwise alter TI’s applicable warranties or warranty disclaimers for TI products.
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2023, Texas Instruments Incorporated