The MAX7219 is an integrated serial input / output common-cathode display driver, which connects the microprocessor with 8-digit 7-segment digital LED display, bar graph display can also be connected or 64 independent LED. On BCD encoder includes an on-chip type B, the multiple scanning loop, segment word drive, but also an 8 * 8 static RAM is used to store data. Only an external register is used to set the current of each LED segment.
A convenient four-wire serial interface can connect all general-purpose microprocessor. Each data can be addressed when the update does not need to rewrite all of the display. MAX7219 also allows users to select a data coding or non-coding. The entire device contains a 150uA low-power off mode, analog and digital brightness control, a scan-limit register allows the user to display 1-8 bit data, there is a LED light detection mode.