SNVSBA5C December 2019 – May 2024 LP8866-Q1
PRODUCTION DATA
The LP8866-Q1 device is a high-voltage LED driver for automotive infotainment, clusters, HUD and other automotive display LED backlight applications. PWM input is used for brightness control by default. Alternatively, the brightness can also be controlled by I2C Interface.
The boost frequency, LED PWM frequency, and LED string current are configured with external resistors through the BST_FSET, PWM_FSET, and ISET pins. The INT pin is used to report faults to the system. Fault interrupt status can be cleared with the I2C interface, or is cleared on the falling edge of the EN pin.
The LP8866-Q1 supports pure PWM dimming. The six LED current drivers provide up to 200mA per output and can be tied together to support higher current LEDs. The maximum output current of the LED drivers is set with the ISET resistor and can be optionally scaled by the LEDx_CURRENT[11:0] register bits with I2C interface. The LED output PWM frequency is set with a PWM_FSET resistor. The number of connected LED strings is configured by the LED_SET resistor, and the device automatically selects the corresponding phase shift mode. For example, if the device is set to 4-strings mode, each LED output is phase shifted by 90 degrees with each other (= 360 / 4). Unused outputs, which must be connected to GND, will be disabled and excluded from adaptive voltage and won't generate any LED faults.
A resistor divider connected from VOUT to the FB pin sets the maximum voltage of the boost. For best efficiency, the boost voltage is adapted automatically to the minimum necessary level needed to drive the LED strings by monitoring all the LED output voltages continuously. The switching frequency of the boost regulator can be set between 100kHz and 2.2MHz by the BST_FSET resistor. The boost has a start-up feature that reduces the peak current from the power-line during start-up. The LP8866-Q1 can also control a power-line FET to reduce battery leakage when disabled and provide isolation and protection in the event of a fault.
Fault detection features of LP8866-Q1 include: