An 800-mA Time-Based Boost Converter in 0.18µm BCD with Right-Half-Plane Zero Elimination and 96% Power Efficiency

This work presents a novel boost converter with time-based control for LED display applications. Using the inductor current, the right-half-plane zero of the CCM control-to-output transfer function is eliminated to improve dynamic performances with no extra off-chip component or power switch. To increase efficiency at light loads, a PFM operating mode with seamless PFM-to-CCM transition is included. The prototype implemented in a 0.18µm BCD process provides a regulated output voltage of 5V with a 2.5-to-4.5V input voltage range. With a 3.5V input, the efficiency reaches a peak of 96%, while it is above 90% down to 10mA loads. The area occupation of the time-based PID controller is about 0.16 square millimeters with a quiescent current of 300µA. The converter bandwidth is increased by a factor of about 5 with respect to a standard compensation scheme.