In this work, we improved a wireless power supply platform for an ultra-small device. Previously, we realized a CMOS-integrated optical power receiver that can drive an InGaN blue LED. To operate the InGaN LED in constant-current mode, we introduced a current-limiting function in the CMOS control circuit. This current limitation was realized with NMOS current sources at the cathodic side of the LED. The concept, design, and characteristics will be presented at the conference.