- The LM3431Q/LM3431AQ is an AEC-Q100 Class 1 qualified (-40°C to 125°C operating junction temperature) grade for automobiles
- 3-channel programmable LED current
- High accuracy linear current regulation
- Analog and digital PWM dimming control
- Dimming frequency up to 25kHz
- > 100:1 contrast ratio
- Integrated boost controller
- 5V - 36V input voltage range
- Adjustable switching frequency up to 1MHz
- LED short-circuit and open-circuit protection
- You can choose to shut down or automatically restart the fault
- Programmable fault delay
- The programmable period is limited by the cycle current
- Output overvoltage protection
- No noise
- Enable pin
- LED overtemperature shutdown input
- Thermal shutdown
- TSSOP-28 package exposed pad
illustrate
The LM3431 is a three-channel linear current controller, an switching controller that drives space critical applications in the ideal combination of LED backlit panels. The LM3431 driver has 3 external NPN transistors or MOSFETs to provide high accuracy constant current to 3 LED strings. The output current can be adjusted to drive a 200 mA excess string. The LM3431 can be extended to drive up to 6 LED strings.
A step driven by the boost controller regulates an external NFET switch from an input voltage between 5V and 36V. The LM3431 features LED cathodic feedback to adjust the space to minimize and optimize efficiency.
A DIM input pin controls the brightness of the LED from analog or digital control signals. Dimming frequencies up to 25 kHz are possible with a contrast ratio of 100:1. Contrast ratios greater than 1000:1 are possible at lower dimming frequencies.
The LM3431 eliminates the noise problem during dimming of regulated LEDs that maintain a constant output voltage. Other features include LED short-circuit and open-circuit protection, fault delay/error flags, cycle-by-cycle current limiting, and simultaneous thermal shutdown of the IC and LED array. Enhanced LM3431A functionality reduction offsets higher accuracy voltge LED current.
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- Automotive infotainment displays
- Small to medium format display
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