ZHCSGN5B March 2017 – July 2018 LP8863-Q1
PRODUCTION DATA.
The LP8863-Q1 supports a cluster mode like that found in the LP8860-Q1 LED driver. This mode allows the brightness of each of the six driver channels to be controlled independently using the I2C or SPI interface. This is done by using the six CLUSTER_BRTx[15:0] registers, the six LEDx_GROUP registers and the LED_EXT_SUPPLY[5:0] register.
The LEDx_GROUP registers select which CLUSTER_BRTx or DISP_BRT register is used for each of the six LED driver channels. The LED_EXT_SUPPLY[5:0] register selects which channels are used by the adaptive boost voltage control loop. This allows the LP8863-Q1 to drive LED strings that powered with either the integrated boost controller or external supply. If a LED driver channel is driving a string powered from the boost then its corresponding LED_EXT_SUPPLY bit should be set to zero. By default all LED_EXT_SUPPLY bits are 0, and all LEDx_GROUP bits are 000.
An example of how the registers would be configured if the application calls for a display backlight with 4 strings and uses the remaining 2 current sinks to drive indicator LEDs where anodes are supplied externally (not from the boost of the LP8863-Q1 device) follows:
LED_EXT_SUPPLY[5:0] = 11000b | (LED5 and LED4 use external supply ) |
LED0_GROUP = 000b | (LED0 uses DISP_BRT register) |
LED1_GROUP = 000b | (LED1 uses DISP_BRT register) |
LED2_GROUP = 000b | (LED2 uses DISP_BRT register) |
LED3_GROUP = 000b | (LED3 uses DISP_BRT register) |
LED4_GROUP = 100b | (LED4 uses CLUSTER_BRT4 register) |
LED5_GROUP = 101b | (LED5 uses CLUSTER_BRT5 register) |