Capacitive Power Supply Application Note

Choosing and using bypass capacitors application note an1325rev 1 00 page 1 of 11 oct 10 2011 an1325 rev 1 00 oct 10 2011 introduction.

Capacitive power supply application note. Power supply is the bypass capacitor. A 3x voltage inverter is made with a sot charge pump ic and diode capacitor network. Figure 1 capacitive transformerless ac to dc power supply with common hot. Application notes all you need to know for further development.

The 120 vac 60 hz design is different than a 230 vac 50 hz circuit. Len sherman feb 03 2003 abstract. Application note an alternative solution to capacitive power supply using buck converter based on viper12a introduction in this paper three different power supplies with two outputs are introduced. The class of x2 capacitor is intended for.

Since the front end. On a capacitive power supply. Charge pump dc dc converter inverter inverting power supply dc to dc convertors application note 1875 triple capacitive voltage inverter with the max871 by. The supply current for the microcontroller is obtained from the input voltage.

A shunt can be used for the current sensing element. A capacitive passive network and two versions of a low cost smps buck converter. Disadvantages of capacitive power supply. Figure 2 capacitive transformerless ac to dc power supply with common neutral.

App note description devices link. The last two are. Higher cost than a resistive power supply. Transformerless power supply calculator this tool calculates output parameters of a transformerless power supply where a capacitor is used to drop the voltage.

Not isolated from the ac line voltage which introduces safety issues. The capacitive power supply in this application is designed to ensure that there is enough energy to run it even with the input voltage of 110 v iout 6 11 ma due to the fairly large capacitor being used c4 330 nf. This use of a capacitive power supply and a shunt for current sensing mak e the mc9s08gw64 suitable for a very low cost bill of material bom energy meter. Power supply is more efficient than a resistive transformerless power supply discussed next.

Grounding effects in the power supply of capacitive sensors. Capacitive drop supply is essentially a voltage divider such that a series capacitor drops the input voltage down to a more usable level. Each capacitive drop supply is good for a narrow range of ac line voltage and ac line frequency applications. Up to 15v at 10ma can be generated from 5v.

The formulas and information come from microchip application note an954 written by reston condit. Application notes all you need to know for further development.