The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 04, 2017
Filed:
Jun. 09, 2015
Leadtrend Technology Corp., Hsin-Chu, TW;
Ching-Tsan Lee, Hsin-Chu, TW;
Leadtrend Technology Corp., Hsinchu County, TW;
Abstract
A controller for dimming light-emitting diodes includes a pulse width modulation pin, a low-pass filter, a frequency detection unit, and a control signal generation module. The low-pass filter generates a direct current signal according to a pulse width modulation signal generated by a micro-controller. The frequency detection unit generates a logic value according to a threshold and the pulse width modulation signal. The control signal generation module generates a switch control signal to a first switch connected to the light-emitting diodes in series according to the direct current signal, the logic value, a reference voltage, and the pulse width modulation signal. When a frequency of the pulse width modulation signal is lower than the threshold, the controller enters a digital dimming mode; and when the frequency of the pulse width modulation signal is higher than the threshold, the controller enters an analog dimming mode.