High-Speed Dynamic Level Shifter for High-Side Bootstrapped Gate Driver in High-Voltage Buck Regulators
Bing Yuan, Lang-Qi Xiao, Bingyuan Wang, Ying Jing
Abstract
Considering the high-voltage dc-dc buck regulator applications, a high-speed dynamic level shifter for high-side bootstrapped gate driver is presented. By introducing an instantaneous dynamic current, the propagation delay of the level shifter is reduced to 0.25 ns for the high-side switch. The dV <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{SW}/dt$ </tex-math></inline-formula> immunity and reliability are improved by a clamp circuit during the positive and negative slewing. The maximum dV <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{SW}/dt$ </tex-math></inline-formula> that the proposed circuit can tolerate is up to 18V/ns. The process variation immunity is also enhanced by optimizing the design of bias current generator. The achieved area-efficient level shifter is designed based on thin gate-oxide transistors that are widely used in high-voltage process. Experimental results show that the fabricated regulator with the proposed scheme regulates well with an 18 V input, 3.3 V output, and 2 A load current.