The MAX7219/MAX7221 are compact, serial input/output common-cathode display drivers that interface microprocessors (µPs) to 7-segment numeric LED displays of up to 8 digits, bar-graph displays, or 64 individual LEDs.
The MAX7219 and MAX7221 are compact serial‑input, common‑cathode LED display drivers that interface microprocessors to up to eight 7‑segment digits, bar‑graph displays, or 64 individual LEDs. They include an on‑chip BCD decoder, multiplex scan circuitry, segment and digit drivers, and an 8×8 static RAM for storing display data. Only a single external resistor is required to set the segment current for all LEDs.
The devices operate from a 5 V supply, support SPI, QSPI and MICROWIRE serial interfaces, and provide features such as low‑power shutdown, analog and digital brightness control, and a test mode that forces all LEDs on. They are offered in 24‑pin DIP, SO and CERDIP packages and are rated for temperatures from –40 °C to +85 °C depending on the part variant.