Boost converter
An inductor is coupled at one end to an input line. A switching transistor and a shunt resistor are coupled in series between the other end of the inductor and a ground line. A rectifier diode is coupled between the other end of the inductor and an output line. A converter controller controls the switching transistor according to at least a voltage drop across the shunt resistor. A first output capacitor has one end coupled to the output line, and the other end coupled to a connection node that couples the switching transistor and the shunt resistor.
1 . A boost converter comprising:
an input line structured to receive an input voltage;
an output line to be coupled to a load;
an inductor having one end coupled to the input line;
a switching transistor and a shunt resistor coupled in series between another end of the inductor and a ground line;
a rectifier element coupled between the another end of the inductor and the output line;
a converter controller structured to control the switching transistor according to at least a voltage drop across the shunt resistor;
a first output capacitor having one end coupled to the output line and another end coupled to a connection node that couples the switching transistor and the shunt resistor; and
a second output capacitor having one end coupled to the output line and another end coupled to the ground line,
wherein the switching transistor, the shunt resistor, the rectifier element, the first output capacitor, and the second output capacitor are mounted on a printed circuit board, and
wherein a closed loop formed of the switching transistor, the rectifier element, and the first output capacitor on the printed circuit board has an area that is smaller than an area of a closed loop formed of the switching transistor, the rectifier element, the shunt resistor, and the second output capacitor.
2 . The boost converter according to claim 1 , wherein the first output capacitor has a capacitance that is smaller than that of the second output capacitor.
3 . The boost converter according to claim 1 , wherein the first output capacitor has a capacitance that is smaller than 1/10 of that of the second output capacitor.
4 . The boost converter according to claim 1 , wherein the switching transistor has a switching frequency of 100 kHz to 2 MHz,
and wherein the first output capacitor has a capacitance of 100 μF to 0.1 μF.
5 . The boost converter according to claim 1 , wherein the rectifier element is configured as a diode.
6 . The boost converter according to claim 1 , wherein the rectifier element is configured as a synchronous rectification transistor.
7 . The boost converter according to claim 1 , wherein the load comprises a plurality of light-emitting elements coupled in series.