AN2317 - Application

External Circuit Design

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1.5.2

Capacitive Power Supply

There are several ways to convert AC voltage into the DC voltage required by STPM01.

Traditionally, this is done with a transformer and rectifier circuit. There is also switching

power supply solution. However, these two solutions are expensive and take up a

considerable amount of PCB space.

To provide a low-cost, alternative solution, a transformerless power supply can be used (see

Figure 12).

Figure 12.

Capacitive Power Supply

VDD

UIN

IIN

GND

D3

5.1V

D2

DIF60

D1

DIF60

LINE

NEUTRAL

AI12914

1

2

R1

82R

C3

1000m

C2

470n