MAX7219 Dot Matrix Display Driver IC

The MAX7219 is a constant current LED display driver IC that can drive 7-segment LED displays, 64×64 LED matrix or individual LEDs. It communicates with a microcontroller through a simple serial interface and features built-in BCD decoder and 8×8 static RAM.

• 10MHz Serial Interface
• Individual LED Segment Control
• Decode/No-Decode Digit Selection
• 150µA Low-Power Shutdown (Data Retained)
• Digital and Analog Brightness Control
• Display Blanked on Power-Up
• Drive Common-Cathode LED Display
• 24-Pin DIP and SO Packages

Pinout Description:

• DIN: Serial data input
• DIG0–DIG7: Current sink for each common cathode
• GND: Chip ground (connect both pins)
• LOAD: 16-bit data latch
• CLK: Serial clock input (10MHz max)
• SEG A–SEG G, DP: Current source for segments and decimal point
• ISET: Source current set pin
• V+: VCC, 5.5V max
• DOUT: Serial data output for daisy-chaining

The source current is set by a resistor between VCC and ISET (minimum 9.5KΩ for 40mA segment current). Intensity can be controlled digitally via 16 intervals (1/32 to full brightness). The chip has a 16-bit input register (MSB first) with data bits D0–D7, address bits D8–D11. Display test mode (address 0xF) turns on all LEDs; shutdown mode (address 0xC) reduces current to 150µA. Available in 24-pin DIP package (breadboard friendly).