CURRENT DETECTION CIRCUIT AND CURRENT MODE DC/DC CONVERTER USING CURRENT DETECTION CIRCUIT

摘要

PPROBLEM TO BE SOLVED: To provide a current detection circuit whose temperature dependency is extremely small and a current mode DC/DC converter. PSOLUTION: This current detection circuit is provided with: a first series circuit where a first conductor Rs1 and a load 1 are serially connected; a second series circuit where a second conductor Rs1 having the same temperature characteristics as the temperature characteristics of the resistance of the first conductor Rs1 is serially connected to a resistance R1; a power source Vin for supplying a voltage to the first series circuit and the second series circuit; and a control circuit for controlling the voltage drop of the second conductor Rs2 to the same voltage as the voltage drop of the first conductor Rs1 (configured of an arithmetic amplifier circuit 2 and a PMOS transistor 5), and configured to generate a current detection signal Vsense corresponding to load currents on the basis of currents flowing to the second conductor Rs2. The first conductor Rs1 and the second conductor Rs2 can be replaced with a PMOS transistor having the temperature characteristics of an on-resistance equal to each other. PCOPYRIGHT: (C)2007,JPO&INPIT