Abstract : A novel method for current sensing in switching regulators is proposed. Utilizing the relationship between the load current and the gate drive signal N_DRV of the synchronous transistor in discontinuous mode (DCM), the output load current of the switching regulator is detected by sensing this gate signal. This method reduces the circuit complexity associated with directly sensing the average inductor current, saving chip design costs. Employing a 0.5μm CMOS process, Hspice simulations verify that it consumes only 5μA of quiescent current. Keywords : Switching regulator; Discontinuous mode (DCM); Current sensing 1. Introduction With the trend towards miniaturization and portability in electronic products, monolithically integrated high-efficiency, low-supply-voltage DC-DC converters are widely used. Current sensing circuits are used in many power management ICs. In current-mode PWM controlled DC-DC converters, the current sensing module is an important part of the current loop, used to detect the current flowing through the power transistor and inductor. By comparing the current sensing result with the output of the voltage loop, pulse width modulation is achieved. In circuits such as voltage-mode pulse-width modulation DC-DC converters (PWM DC-DC converters), low-dropout linear regulators (LDOs), and charge pumps, it can also be used for energy-saving and protective purposes such as open-circuit, short-circuit, and overcurrent detection. There are three traditional current sensing methods: using the RDS of the power transistor; using a sensing field-effect transistor; and combining a field-effect transistor with a sensing resistor. For switching regulators, unlike traditional current sensing methods, this paper proposes a novel method for detecting the load current of switching regulators. 2. Traditional Current Sensing Methods 2.1 Detection using the RDS of the Power Transistor (RDS SENSING) We know that when a power MOSFET is turned on, it operates in the variable resistance region and can be equivalent to a resistor. This equivalent resistance is: A Novel Current Sensing Method Applicable to Switching Regulators (Full Text Download)