Application information

STWLC04

12/18

DocID029626 Rev 2

Figure 6: VIO and digital interface in platform application schematic

4.2

External passive component selection

4.2.1

Input resonant circuit component selection (L1, C1, C2)

RX coil selection should be optimized by the requested transferred power. The inductance

have to be carefully selected both to keep the resonant frequency compliant with the

wireless standard specification and also to deliver the power. For more details please see

wireless standard specifications.

The following equations list the resonant frequencies:

Equation 1:

1

Equation 2:

1

1

1

It is recommended high grade ceramic capacitors to be used with C0G dielectrics type.

X5R, X7R capacitors can be used for 5 W output power applications.

4.2.2

Voltage clamp resistor selection (RCL1, RCL2)

The purpose of these resistors is to load the rectifier output by decreasing the rectified

voltage below overvoltage threshold

0.2 W resistors with pulse-withstanding character are recommended for this application.