ADIMAX7221EWG+
Overview
The MAX7221EWG+ is a compact, serial input/output common-cathode display driver designed to interface microprocessors to 7-segment numeric LED displays of up to 8 digits, bar-graph displays, or 64 individual LEDs. It includes an on-chip BCD code-B decoder, multiplex scan circuitry, segment and digit drivers, and an 8x8 static RAM that stores each digit. The device features slew-rate limited segment drivers to reduce electromagnetic interference (EMI) in sensitive environments.
Why Choose This Part
This driver simplifies system design by managing all display multiplexing and refreshing internally, freeing up the host microcontroller's resources. It supports a low-power shutdown mode that drops supply current to 150uA while retaining data, and its SPI/QSPI-compatible interface allows for high-speed communication with only three wires.
Applications
Key Specifications
Getting Started
To implement the MAX7221EWG+, connect a single external resistor to set the segment current for all LEDs and use 0.1uF and 10uF bypass capacitors near the V+ pin. Firmware development is straightforward using standard SPI libraries; simply send 16-bit packets consisting of an address byte and a data byte to configure brightness, scan limit, and digit data.
