I am interested in starting an intro electronics project using a IR sensor and am having a little trouble understand the application circuit given on the datasheet of the circuit. The value of resistor they recommend using is far less then the one I calculate I should need.
The supply current given on the datasheet is 0.27mA - 0.45mA and the supply voltage is 2.5V - 5.5V. I intend to run this sensor at 0.35mA with 3.3V and this yields a needed resistance of around 10K ohms; far greater than the 33 - 1K ohms suggested.
As this is my first venture into electronics, could someone help me to understand how using such a low resistor as specified would work when the math says otherwise?
On a slightly related note, from what I understand, the capacitor in the circuit is called a decoupling capacitor and is used to provide the extra current during short periods of high current draw so the voltage supply does not. Because this is such a low current circuit (or is 0.35mA low?), is it fine if I leave the capacitor out or should I include it because the datasheet lists the absolute maximum current as 3mA and the circuit may try to draw that much?
Also, I am not familiar with the component on the far right of the diagram (marked "micro" C). Is that a generic representation of a microchip?