When the switch 104 closes, an electrical connection is created between the common voltage 110 and the first reference voltage 112. This causes current from current source 102 to transmit through the LED 103 enabling light to emit from the sub-pixel 72. Thus, emission periods of the sub-pixel 72 may be varied to control a perceived light emitted from the sub-pixel 72, where the emission periods correspond to a bit placement (e.g., most significant bit, least significant bit) of the image data 98 stored in the memory 78 such that the closer a bit of image data 98 is to the most significant bit position, the longer an emission period corresponding to that bit of image data 98. Once the counter 105 counts up to 11, the counter 105 restarts and causes the bit-plane clock 106 to restart its clocking intervals, for example, to correspond to a next least significant bit after the last most significant bit emission period. Additionally or alternatively, in some embodiments, the second reference voltage 114 is included to alter an overall current value used to control light emitted from the LED 103. For instance, the second reference voltage 114 may increase a sensitivity of the LED 103 to current changes such that a lower current value may be used to cause light to emit from the LED 103, or used to enable the LED 103.