Low cost LED driver with improved serial bus

摘要

An LED driver IC for driving external strings of LEDs comprises a prefix register and a data register connected in series with each other and with the prefix and data registers in other driver ICs. The prefix and data registers of the driver ICs are connected in a daisy chain arrangement with an interface IC. The interface IC loads data identifying a functional latch into the prefix register and data defining a functional condition into the data register of each driver IC. The data in the data register is then transferred to the functional latch to control the functional condition within the LED driver IC.

主权项

1. A system for controlling a plurality of light emitting diode (LED) strings in a video display, each of the plurality of LED strings associated with a channel of a plurality of channels, the system comprising:
a plurality of LED driver integrated circuits (ICs), each of the plurality of LED driver ICs including a serial shift register, a multiplexer, and an analog control and sensing circuit constructed to detect a fault condition associated with the system, the analog control and sensing circuit being configured to connect to at least two LED strings of the plurality of LED strings and being coupled to a first input of the multiplexer; and a serial lighting interface bus, the serial lighting interface bus-including the serial shift register in each of the plurality of LED driver ICs connected in a daisy-chain, the serial shift register in each of the plurality of LED driver ICs including a prefix register constructed to hold data identifying a function within at least one channel of the plurality of channels and a data register constructed to hold data representing a value of the function within the at least one channel, the data register being coupled to a second input of the multiplexer.