Automotive Display 6-Channel LED Backlight Driver with I²C Interface

The RTQ4551-QT is a 6-channel LED driver capable of delivering 200mA for each channel with a DC-DC controller. The current-mode switching DC-DC controller supports boost or SEPIC topologies and operates in the 300kHz to 2.2MHz frequency range. The device accepts a wide 3V to 40V input voltage range and withstands direct automotive cold crank and load-dump events. The internal current sinks support a maximum of 3.5% current accuracy and mismatching for excellent brightness uniformity in each string of LEDs. The RTQ4551-QT automatically detects and disconnects any unconnected and/or broken strings during operation from control loop to prevent VLED from overvoltage. To provide enough headroom for current sink operation, the boost controller monitors the minimum voltage of the LEDx pins and regulates an optimized output voltage for power efficiency. The RTQ4551-QT has a standard I²C digital interface for functional settings. Moreover, the boost switching and PWMO frequency can be programmed by external resistors or the I²C interface. Comprehensive diagnostic information is also available through the I²C interface. When an abnormal situation occurs, a status signal will be sent to the system.The RTQ4551-QT is available in a 38-pin VDFN package and operates within a temperature range of -40°C to 125°C.