CURRENT SENSOR FOR COMPENSATING INPUT OFFSET AND OUTPUT DELAY OF VOLTAGE AMPLIFIER

摘要

The present invention relates to a current sensor compensating an input offset and an output delay of a voltage amplifier comprising: an I_zero pulse generator which corresponds to I_zero signals output from a voltage amplifier where both ends of a power switch are connected to input ends and controls the power switch; a comparator which is connected to the both ends of the power switch and measures a delay error of input offset voltage and an output value; and an up-down charge pump which adjusts bias voltage of the voltage amplifier from the output of the comparator, and controls the generating time of the I_zero signals. According to the present invention, the comparator measures the delay error of the input offset and the output value of the voltage amplifier, and the comparator output operates the up-down charge pump to adjust the bias voltage of the voltage amplifier, such that an error of currents measurement can be removed. Therefore, the present invention accurately senses the moment when an inductor current is 0 and turns on/off a power NMOS without delay, thereby improving a power efficiency.;COPYRIGHT KIPO 2016