Top

8-Port, 36V Constant-Current LED Driver

Industry-Standard Operation, 36V-Tolerant Outputs

Product Details

Key Features

Simplified Block Diagram

Technical Docs

Data Sheet 8-Port, 36V Constant-Current LED Driver Nov 14, 2005

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .

Key Features

  • 25Mbps Industry-Standard 4-Wire Serial Interface at 5V
  • 3V to 5.5V Logic Supply
  • Eight Constant-Current LED Outputs Rated at 36V
  • Up to 55mA Continuous Current per Output
  • Output Current Programmed by Single Resistor
  • 3% Current Matching Between Outputs
  • 6% Current Matching Between ICs
  • -40°C to +125°C Temperature Range

Applications/Uses

  • Architectural Lighting
  • Gaming Features
  • Marquee Displays
  • Point-of-Order Signs
  • Traffic Signs
  • Variable Message Signs

Description

The MAX6970 serial-interfaced LED driver provides eight open-drain, constant-current-sinking LED driver outputs rated at 36V. The device operates from a 3V to 5.5V supply. The MAX6970 supply and the LEDs' supply can power up in any order. The constant-current outputs are programmed together up to 55mA using a single external resistor. The MAX6970 operates with a 25Mbps, industry-standard, 4-wire serial interface.

The MAX6970 uses the industry-standard shift-register-plus-latch-type serial interface. The driver accepts data shifted into an 8-bit shift register using data input DIN and clock input CLK. Input data appears at output DOUT eight clock cycles later to allow cascading of multiple MAX6970s. The latch-enable input, LE, loads the 8 bits of shift register data into an 8-bit output latch to set which LEDs are on and which are off. The output-enable input, active-low OE , gates all eight outputs on and off, and is fast enough to be used as a PWM input for LED intensity control.

For applications requiring LED fault detection, refer to the MAX6981 data sheet that automatically detects open-circuit LEDs.

For safety-related applications requiring a watchdog timer, refer to the MAX6980 data sheet, which includes a fail-safe feature that blanks the display if the serial interface becomes inactive for more than 1s.

The MAX6970 is one of a family of 10 shift-register-plus-latch-type LED drivers. The family includes 8-port and 16-port types, with 5.5V- or 36V-rated LED outputs, with and without open-circuit LED detection and watchdog. All versions operate from a 3V to 5.5V supply, and are specified over the -40°C to +125°C temperature range.

Simplified Block Diagram

MAX6970: Typical Operating Circuit MAX6970: Typical Operating Circuit Zoom icon

Technical Docs

Data Sheet 8-Port, 36V Constant-Current LED Driver Nov 14, 2005

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .