Asymmetrical Dead-Time Control Driver for Buck Regulator

This brief presents an asymmetrical dead-time control driver (ASDTCD) for synchronous buck converter operating in the continuous conduction mode. Dead-time control is an important metric for improving the efficiency of switching mode power regulator. Without an additional circuit, the proposed ASDTCD can generate dead time by controlling the slope for the output signal of the driver. The proposed ASDTCD utilizes the transition between triode region and saturation region for the power transistor to avoid body-diode conduction and shoot-through current while minimizing the switching loss. Thus, high-speed body-diode conduction sensor is avoided; thereby, reducing the power consumption and saving silicon area. In addition, the body-diode conduction time control accuracy is also enhanced. Less than 1-ns body-diode conduction time has been achieved without bringing in shoot-through current across 10-450-mA load range. With less than 0.5% of the total input power consumed, the proposed ASDTCD takes less than 1% of the power transistor area. This design is implemented in the 0.18 μm CMOS process.