A 630dpi dynamic LED display array in standard Si-based CMOS technology

A novel silicon light emitting diode (LED) display array has been fabricated using 0.35 μm standard CMOS technology. In this array, an LED and static random access memory (SRAM) are integrated together in a special layout. The SRAM in each pixel can store the state of the pixel and ensure that the pixel remains lit without persistent flashing. As a result, the control logic is perfectly integrated on the same wafer. Two power sources are used to drive the display array because the LEDs operate at high voltage (supply voltage of 9 V), and the current of the whole display array is about 30–60 mA to display common characters. The display circuit includes digital control logic circuits and SRAM, and requires a supply voltage of 3.3 V. The area of a single pixel is 40×40 μm 2 , the area of the whole 16×16 LED array is 1 mm 2 , and the display density is 630 dpi.