AN2451 datasheet(13/55 Pages) STMICROELECTRONICS

13 / 55 page

AN2451

Board description

Doc ID 12791 Rev 3

13/55

Board description

The ST7540 reference design is composed of the following sections:

●

Power supply section, based on ST’s VIPer12A-E IC

●

ST7540 modem and crystal oscillator section

●

Line coupling interface section, with three subsections:

–

Transmission active filter

–

Transmission passive filter

–

Receiving passive filter.

The board also has two connectors, which allow the user to plug the mains supply on one

side of it and the I.B.U. communication board on the other side.

Figure 6.

Positioning of the various sections of the board

The schematics of the whole reference design appear in Figure 7 and 8. Figure 7 shows

the modem and the coupling Interface circuits, while Figure 8 represents the power supply

circuit. In both the schematics, high voltage regions are highlighted.

Table 3 lists the components used to develop the reference design board. All parts have

been selected to give optimal performances.

The layout of the printed circuit is given in Appendix A - Figure 49, Figure 50 and Figure 51.

AN2451 Datasheet(PDF) 13 Page - STMicroelectronics