LOW POWER RELAXATION OSCILLATOR AND RFID TAG USING THE SAME

摘要

PURPOSE: A low power relaxation oscillator and a RFID tag using the same are provided to generate a clock signal having a 50% duty ratio by repeating fixed operation. CONSTITUTION: A constant current generating unit(110) generates the current of a predetermined size. A current variant unit(120) controls the current generated from the constant current generating unit according to a clock control signal. First and second controllers(131,132) selectively pass through the current applied in the current variant unit. A PMOS charging and discharging unit(140) is arranged between an output terminal of the first controller and the output terminal of the second controller. First and second comparators(151,152) are respectively connected to both ends of the PMOS charging and discharging unit. The first and the second comparators output a voltage of a high or low level according to a charged voltage to the PMOS charging and discharging unit. A latch circuit(160) outputs an oscillation signal by respectively delaying the outputted voltage form the first and the second comparators.