Texas Instruments LM3431
The LM3431 is a 3-channel linear current controller combined with a boost switching controller ideal for driving LED backlight panels in space critical applications. The LM3431 drives 3 external NPN transistors or MOSFETs to deliver high accuracy constant current to 3 LED strings. The LM3431 can be expanded to drive as many as 6 LED strings.FEATURES
1●2 LM3431Q/LM3431AQ are Automotive Grade Products that are AEC-Q100 Grade 1 Qualified (–40°C to 125°C operating junction temperature)
● 3-Channel Programmable LED Current
● High Accuracy Linear Current Regulation
● Analog and Digital PWM Dimming Control
● Up to 25kHz Dimming Frequency
● >100:1 Contrast Ratio
● Integrated Boost Controller
● 5V-36V Input Voltage Range
● Adjustable Switching Frequency up to 1MHz
● LED Short and Open Protection
● Selectable Fault Shutdown or Automatic Restart
● Programmable Fault Delay
● Programmable Cycle by Cycle Current Limit
● Output Over Voltage Protection
● No Audible Noise
● Enable Pin
● LED Over-Temperature Shutdown Input
● Thermal Shutdown
● TSSOP-28 Exposed Pad Package
DESCRIPTION
Output current is adjustable to drive strings in excess of 200 mA. The boost controller drives an external NFET switch for step-up regulation from input voltages between 5V and 36V. The LM3431 features LED cathode feedback to minimize regulator headroom and optimize efficiency.