BASE CURRENT OF BIPOLAR JUNCTION TRANSISTOR COMPENSATION CIRCUIT AND LED DRIVING APPARATUS HAVING THE SAME

摘要

A bipolar junction transistor (BJT) base current compensation circuit mirrors a base current of a BJT to induce a mirroring current and is connected to an emitter terminal of the BJT to reduce as much current flowing through the emitter of the BJT as the mirroring current. An LED driving apparatus includes: an LED array; a BJT connected to the LED array in series; a detection part connected to the emitter of the BJT to measure a current flowing through the LED array; a differential motion amplifier which differentially amplifies a reference potential and the current measured by the detection part and supplies a base current to a base of the BJT; and a BJT base current compensation circuit which induces a mirroring current by mirroring the base current and is connected to the emitter terminal of the BJT to reduce as much current flowing through the emitter of the BJT as the mirroring current. Therefore, the LED driving apparatus can accurately measure the current flowing through the LED and control the LED current by removing the base current included in the emitter current of the BJT.