Patent ID: 9099137
Filing Date: 2015-08-04
Classification: G11B,H03F

Abstract:
1. An amplifier circuit, comprising: a first node configured to receive a first current; a second node configured to receive a reference voltage; feedback circuitry configured to form a feedback loop that generates and maintains a bias voltage on the first node based on the reference voltage at the second node, wherein the feedback circuitry comprises a bipolar transistor having a base terminal connected to the first node, and wherein the bipolar transistor is configured to amplify the first current so as to provide a second current; a reference circuit configured to generate a scaled version of the second current; and a comparing circuit configured to compare an output voltage with an output reference voltage to detect when the first current is at a predetermined level, wherein the output voltage is generated based on the second current, and wherein the output reference voltage is generated based on the scaled version of the second current.