Placing Multiple Rank LEDs in the same circuit design can lead to noticeable brightness variation and re-work of the LED current setting resistors. The slide shows an example of a multiple rank LED circuit designed for “Q” rank LED brightness (71 mcd to 112 mcd) with a 330 Ohm current setting resistor. When an “N” rank LED (28 mcd to 45 mcd) is used with a 330 Ohm resistor, the LED output becomes noticeably dimmer than the previous example. The current setting resistor would need to be changed in order to show the same brightness with the dimmer LEDs. Thus, when using ROHM’s SML-D15 Single Rank LEDs, brightness consistency is improved and there is no need to change current setting resistors.