IC LED driver MAX20069 series

backlighting

The MAX20069 is a highly integrated TFT power supply and LED backlight driver IC for automotive TFT-LCD applications. The IC integrates one buck-boost converter, one boost converter, two gate-driver supplies, and a boost/SEPIC converter that can power one to four strings of LEDs in the display backlight. The source-driver power supplies consist of a synchronous boost converter and an inverting buck-boost converter that can generate voltages up to +18V and down to -7V. The positive source driver can deliver up to 120mA, while the negative source driver is capable of 100mA. The positive source-driver supply regulation voltage (VPOS) is set by connecting an external resistor-divider on FBP or through I2C. The negative source-driver supply voltage (VNEG) is always tightly regulated to -VPOS (down to a minimum of -7V). The source-driver supplies operate from an input voltage between 2.8V and 5.5V The gate-driver power supplies consist of regulated charge pumps that generate up to +28V and -21.5V and can deliver up to 3mA each. The IC features a quad-string LED driver that operates off a separate input voltage (VBATT) and can power up to four strings of LEDs with 150mA (max) of current per string. The IC features logic-controlled pulse-width-modulation (PWM) dimming, with minimum pulse widths as low as 500ns with the option of phase shifting the LED strings with respect to each other. When phase shifting is enabled, each string is turned on at a different time, reducing the input and output ripple as well as audible noise. With phase shifting disabled, the current sinks turn on simultaneously and parallel connection of current sinks is possible.