MAX6969 chip 16-port 5.5V constant current LED driver circuit diagram

The MAX6969 is a serial-interface LED driver that provides 16 open-drain, constant-current-sink, 5.5V-rated LED driver outputs. The MAX6969 operates from 3V to 5.5V supplies. The MAX6969 and LED power supplies can be powered up in any order. All constant current outputs are set with an external resistor up to 55mA each. The MAX6969 is controlled using a 25Mb, industry-standard 4-wire serial interface.

The MAX6969 uses an industry-standard shift register plus latch serial interface. Data is shifted into the 16-bit shift register through data input DIN and clock input CLK. After 16 clock cycles, the input data appears on the output DOUT, allowing multiple MAX6969s to be cascaded. The latch enable input LE loads the 16-bit data of the shift register into the 16-bit output latch to set the switching state of each LED. Output enable/OE controls the switching status of all 16 outputs, and its fast response characteristics are suitable as a PWM input for controlling LED brightness.

For applications requiring LED failure detection, consider the MAX6984*, which automatically detects open LEDs.

For safety-related applications that require a watchdog timer, consider the MAX6979, which has a fail-safe feature that turns off the output if the serial interface stops operating for more than 1 second.

The "shift register + latch" type LED driver family to which the MAX6969 belongs contains a total of 12 members. These include 8 -port and 16-port types, with 5.5V or 36V rated LED output, and some models have LED open circuit detection and watchdog functions. All models operate from 3V to 5.5V supplies and are guaranteed to perform over the -40°C to +125°C operating temperature range.

Key Features

25Mb industry standard, 4-wire, 5V serial interface

3V to 5.5V logic power supply

16 constant current LED drivers with output voltage rated to 5.5V

Outputs up to 55mA continuous current per channel

Setting the output current with a single resistor

3% current matching between outputs

6% current matching between ICs

High thermal capability 24-pin package

-40°C to +125°C temperature range

Certified by Underwriters Laboratories (UL)

Application/Use

architectural lighting

Game features

Marquee display

process sign

traffic light

information board

This product is derived from a 12-shift register latch LED driver family that offers 8-port/16-port, rated 5.5V and 36V outputs, with/without LED fault detection and watchdog timer.

Typical working circuit