Patent ID: 7667914

Claim:
A circuit for amplifying data signals, the circuit comprising: a magnetoresistive sensor having a bias voltage applied thereto; a signal amplifier which amplifies a signal detected by the magnetoresistive sensor having the bias voltage applied thereto; a feedback control block which is coupled to an output of the signal amplifier and outputs a feedback current used to vary a loop gain of the circuit; a bias setting circuit which outputs a bias setting current; a transimpedance amplifier which receives the bias setting current from the bias setting block and the feedback current from the feedback control block and generates the bias voltage applied to the magnetoresistive sensor, the circuit further comprising: a current summing unit which acquires a sum of the bias setting current and the feedback current received by the transimpedance amplifier; an analog-to-digital converter which converts the sum of the bias setting current and the feedback current to a digital value; and a bias logic register which stores the digital value received from the analog-to-digital converter and outputs the digital value to the bias setting circuit to modify the bias setting current based on the digital value.