Maxim MAX7219 LED Driver Chip
Maxim Integrated MAX7219 8-Digit LED Display Driver. Compact, serial input/output common-cathode (can be used with common-anode) display drivers that interface\microprocessors to 7-segment numeric LED displays of up to 8 digits, to bar-graph displays, or to 64 individual LEDs.
Included on-chip are a BCD code-B decoder, multiplex scan circuitry, segment and digit drivers, and an 8x8 static RAM that stores each digit. Only one external resistor is required to set the segment current for all LEDs. A convenient 4-wire serial interface connects to all common microprocessors. Individual digits may be addressed and updated without rewriting the entire display. MAX7219 also allows the user to select code-B decoding or no-decode for each digit. This Maxim Integrated LED display drivers include a 150μA low-power shutdown mode, analog and digital brightness control, a scanlimit register that allows the user to display from 1 to 8 digits, and a test mode that forces all LEDs on.