Lumissil IS32LT3131A/B/C

The IS32LT3131 is a 12 channel current source LED driver IC for automotive rear light animation. It is designed to meet the needs of complex LED lamp systems that utilize hundreds of LEDs to achieve vivid and vibrant animations as found in rear lamp. The IS32LT3131 is an automotive grade linear LED driver that is available in one of three bus interface options. The lamp designer has the option to choose either IS32LT3131A (UART), IS32LT3131B (CANLITE), or IS32LT3131C (SPI) for communication with the host microcontroller (MCU) and other IS32LT3131 devices employing the same bus type. 

Key features

• High speed UART/CANLITE/SPI bus interface with CRC and watchdog timer
• 12 current source channels at 75 mA with +/- 4% accuracy
• 10-bit PWM per channel with slew rate control and spread spectrum
• Fault detection and reporting configurable “One Fail All Fail” or “One Fail Others On”

Additional features

• Wide input voltage supply from 4.5V to 40V
• Thermal shunt resistor to minimize device thermal stress
• UART interface (IS32LT3131A), CANLITE interface (IS32LT3131B), SPI interface (IS32LT3131C) with Lumibus protocol
  • UART/CANLITE interface compatible with CAN physical layer, 100kbps~1Mbps baud rate
  • SPI supports up to 9MHz - CRC to ensure robustness of communication
  • Support up to maximum 16 addressable devices (IS32LT3131A/B)
  • Watchdog timer to support fail-safe mode
     
• 12 current source channel outputs
  • Up to 75mA per channel set by resistor
  • ±4% device-to-device output current accuracy
  • Channels can be combined for higher current capability with same current accuracy
  • Low headroom voltage of 1.2V (Max.) at 75mA
     
• Individual PWM dimming for each channel
  • 10-bit PWM duty cycle setting
  • Programmable PWM frequency up to 31.25kHz
  • PWM phase control minimizes inrush current
  • Current slew rate control and spread spectrum to optimize EMI performance
     
• Individual 8-bit DC current adjustment on each channel
• 32-step global DC current setting
• Fault protection with reporting
  • Programmable fail-safe modes
  • LED string open/short detection
  • Single LED short detection
  • Overcurrent (ISET pin shorted)
  • Overvoltage - CRC error
  • Programmable over temperature current roll-off
  • Thermal shutdown
  • Programmable fault reporting delay time
  • FAULTB pin for hardware fault reporting, allowing parallel bus connection for “One Fail All Fail” or “One Fail Others On” options
     
• Operating temperature range (-40°C ~ +150°C)
• AEC-Q100 qualification in progress
• RoHS & Halogen-Free Compliance
• TSCA Compliance

Applications

• Animation taillight
• Animation daytime running light
• Cluster display