General Description

The MAX6974/MAX6975 precision current-sinking, 24-output PWM LED drivers drive red, green, and blue LEDs for full-color graphic message boards and video displays. Each output has an individual 12-bit (MAX6974) or 14-bit (MAX6975) PWM-intensity (hue) control and 7-bit (MAX6974) or 5-bit (MAX6975) global PWM intensity (luminance) control. The MAX6974/MAX6975 feature a high-speed, fully buffered cascadable serial interface, open-circuit LED fault detection circuitry, as well as a watchdog timer.

Features

♦ 24 LED Current Sink Outputs (Three Banks of Eight Outputs)

♦ 48 LED Drive Option When Multiplexing

♦ 33MHz Clock Supports Up to 63 Frames per Second of Video

♦ Constant Output Current Calibration from 6mA to 30mA in 256 Steps

♦ EZCascade™ Interface Simplifies Multiple Driver Cascading Without External Buffers

♦ 12-Bit or 14-Bit Individual PWM LED Intensity Controls

♦ 7-Bit or 5-Bit Panel PWM-Intensity Control

♦ +3V to +7V LED Power Supply

♦ +3.0V to +3.6V Logic Supply

♦ Open-Circuit LED Fault Detection

♦ Optional Watchdog Timer Blanks Display if Interface Fails

♦ Standard -40°C to +125°C Operating Temperature Range

Applications

LED Video Display Panels

LED Message Boards

Variable Message Signs (VMS)

Signs

Graphic Panels