Lumissil IS32LT3958A

The IS32LT3958A is a multi-topology LED driver with integrated PWM engine to facilitate the design of lighting systems that require dual brightness levels. The boost, buck-boost, and SEPIC topologies enable LED strings to operate with a lower voltage supply. The adjustable operating frequency of up to 1MHz can be sychronized with an external clock source to minimize EMI. Additionally a programable spread spectrum on the clock further lowers EMI to enable passing CISPR-25 and other automotive electromagnetic-compatibility (EMC) test specifications. 

Key features

• Stand alone dual brightness output using internal PWM dimming generator
• Configuable for boost, buck-boost, SEPIC or buck topology
• EMI reduction using programable spread spectrum or external clock synchronization
• +/-2.8% current accuracy over -40°C ~ +150°C operating temperature

Additional features

• Wide high voltage input range: 5V to 70V
• Supports boost, buck-boost, SEPIC and buck topology
• Supports either analog, internal PWM dimming or external PWM dimming
• Excellent fade on control by low duty cycle PWM dimming
• Standalone dual brightness output by internal PWM dimming
  • Integrated PWM generator - 100Hz~1kHz adjustable PWM frequency
  • 5%~100% adjustable PWM duty cycle
     
• Excellent analog dimming capability
  • Two analog dimming pins
  • LED binning capability
  • LED over temperature current roll-off
     
• Externally programmable input undervoltagelockout
• ±2.8% output current accuracy over
  • -40°C ~ +150°C temperature
     
• Adjustable operating frequency range of 100kHz~1MHz
• Programmable soft-start to avoid inrush current
• EMI reduction capabilities
  • Programmable spread spectrum function
  • Operating frequency synchronization with external clock source
     
• Fault protection with reporting:
  • VCC undervoltage lockout (not reported)
  • Programmable output overvoltage protection
  • Output short circuit protection
  • RT/SYNC pin short protection
  • VDD pin short protection
  • VDD undervoltage lockout (not reported)
  • Over temperature protection
     
• AEC-Q100 qualified with temperature grade 1:
  • -40°C to 125°C
     
• RoHS & Halogen-Free compliance
• TSCA Compliance

Applications

• Headlight
• Daytime running light
• Fog light
• Tail light
• Industrial Illumination lighting

Available tools

• IS32LT3958 BUCKBOOST evaluation board
• IS32LT3958 BOOST evaluation board
• IS32LT3958 SEPIC evaluation board
   

For availability and price of the evaluation boards, please contact your local EBV sales.