Design of the Buck Converter without Inductor Current Sensor

Abstract

This paper proposes a novel control scheme for the buck converter without an inductor current sensor. The architecture of the proposed buck converter is simple and suitable for integration and mass production. It employs an output-voltage-measurement method to determine the switch ON time; therefore, the current sensor is not required. The design specification targets the application with a standard battery power source to generate the low voltages for low-power MCU or ASIC. The load current range aims for several hundred milliamps. The proposed control scheme is analyzed and simulated by SIMPLIS. The control scheme, theoretical analysis, circuit realization, contributions, advantages, and simulation results are presented in this paper. Furthermore, the circuit can be fabricated by a 0.35 μm CMOS process.