US Patent 10455653 LED driving circuits

An LED driving circuit for illuminating a first LED unit is provided. The LED driving circuit includes: a data latch circuit, a current source, and a PWM circuit. The data latch circuit latches a data signal according to a first latch signal to generate a first control signal. The current source generates a constant current. The PWM circuit periodically passes the constant current through the first LED unit according to the first control signal and an enable signal.