Light emitting diode driver

摘要

A light emitting diode driver includes: a serial-to-parallel conversion unit converting, based on a reference clock signal, a serial input signal carrying a number (N) of M-bit gray codes into a parallel input signal carrying the M-bit gray codes; a counting unit counting an output control signal to output a counting value; a data buffer unit storing, based on a latch signal, the M-bit gray codes carried by the parallel input signal, and outputting, based on the counting value and the M-bit gray codes, an N-bit signal consisting of N bits, each of which is an ith one of M bits of a respective M-bit gray code, where i is associated with the counting value; and an output unit generating a number (N) of driving current signals based on at least the N-bit signal.

主权项

1. A light emitting diode (LED) driver for generating a number (N) of driving current signals for respectively driving a number (N) of light emitting units, where N≧2, each of the light emitting units including at least one LED, said LED driver comprising:
a serial-to-parallel conversion unit adapted to receive a reference clock signal, and a serial input signal carrying a number (N) of M-bit gray codes, where M≧2, said serial-to-parallel conversion unit being operable to convert, based on the reference clock signal, the serial input signal into a parallel input signal carrying the M-bit gray codes; a counting unit adapted to receive an output control signal, and operable to count the output control signal so as to output a counting value; a data buffer unit adapted to receive a latch signal and coupled to said serial-to-parallel conversion unit and said counting unit for receiving the parallel input signal and the counting value respectively therefrom, said data buffer unit being operable to store, based on the latch signal, the M-bit gray codes carried by the parallel input signal, and to output, based on the counting value and the M-bit gray codes, an N-bit signal consisting of a number (N) of bits, each of which is an ith one of M bits of a respective one of the M-bit gray codes, where 1≦i≦M and i is associated with the counting value; and an output unit coupled to said data buffer unit for receiving the N-bit signal therefrom, said output unit being operable to generate the driving current signals based on at least the N-bit signal.