The wi-fi charger answer makes use of a low-cost microcontroller and allows charging by resonant inductive coupling facilitating environment friendly energy switch between transmitter and receiver.
Wi-fi charging, often known as inductive charging, is an progressive know-how that allows the switch {of electrical} vitality between two coils by electromagnetic induction. Not too long ago, it has gained vital recognition and develop into a outstanding function in varied cell gadgets, together with smartphones. Renesas have launched a reference design for the wi-fi charger to simplify the design course of. The reference design options superior functionalities, corresponding to overcurrent monitoring, that use the sturdy analog capabilities of the used microcontroller unit (MCU). The system contains a charging pad and a suitable system positioned on prime of the pad. Charging happens by resonant inductive coupling, enabling environment friendly energy switch between the 2 parts.
The reference design options Qi, an open interface customary as a wi-fi charging customary. The design operates at a Direct present (DC) energy provide of 5V. The system’s working temperature ranges from -10°C ~ 45°C, and working humidity ranges from 5 ~ 99% RH. The utmost charging present supplied by the wi-fi charger is 800mA, and the utmost output energy is 4 watts. The reference design specification features a visible indication operate as some LEDs are used to point varied info corresponding to detection of a receiver, over present, over temperature, and many others. The design of this technique depends on the RL78/G11 Microcontroller as its core element. Numerous peripherals of the microcontroller, together with analog-to-digital converters, Programmable Acquire Amplifier (PGA), 16-bit timer, timer array unit channel 3, and input-output ports, are strategically utilized to handle particular use circumstances throughout the system.
The wi-fi charging transmitter consists of varied parts, together with a DC 5V energy enter, a present sense amplifier, a voltage detection circuit, a temperature monitor circuit, a foremost MCU, an LED indication circuit, a Pulse Width Modulation (PWM) driver circuit, and a coil. Because of the comparatively excessive consumption present of the wi-fi charging transmitter, the design requires an exterior DC 5V energy adapter to supply the mandatory energy provide. The micropower present sense amplifier ensures environment friendly operation with its extensive enter voltage vary and low energy consumption. If the facility provide voltage falls outdoors the appropriate vary of 4.5V to five.5V, the facility transmission course of is not going to start. For this goal, a voltage detection circuit is included within the design. When the temperature of the transmitter coil constantly measured utilizing a temperature monitoring circuit exceeds the established security threshold of 60°C, the facility transmission shall be routinely halted.
Renesas have examined this reference design. It comes with a Invoice of Materials (BOM), schematics, Printed circuit board (PCB) format, and many others. Yow will discover further information concerning the reference design on the corporate’s web site. To learn extra about this reference design, click on right here.
