Specifications

AN93
Rev. 0.9 137
3.5.19.3.1. Emissions/Immunity
The Si2493/57/34/15/04 chipset and recommended
DAA schematic are fully compliant with and pass all
international electromagnetic emissions and conducted
immunity tests (includes FCC part 15,68; EN50082-1).
Careful attention to the Si2493/57/34/15/04 bill of
materials (page 19), schematic (page 18), and layout
guidelines ensure compliance with these international
standards. In designs with difficult layout constraints,
the addition of R12 and R13 to the C8 and C9
recommended capacitors may improve modem
performance on emissions and conducted immunity. For
such designs, a population option for R12 and R13 may
allow additional flexibility for optimization after the
printed circuit board has been completed. Also, under
some layout conditions, C8 and C9 may improve the
immunity to telephone line transients.
3.5.19.4. Safety
Designs using the Si2493/57/34/15/04 pass all
overcurrent and overvoltage tests for UL1950 3rd
Editions given the addition of a 1.25 A Fuse or PTC, as
shown in Figure 26. In a cost-optimized design, it is
important to remember that compliance to UL1950 does
not always require overvoltage tests. In the design
cycle, it is important to plan ahead and know which
overvoltage tests apply to your system. System level
elements in the construction, such as fire enclosure and
spacing requirements, need to be considered during the
design stages. Consult with your Professional Testing
Agency during the design of your product to determine
which tests apply to your system.
Figure 26. Circuits that Pass All UL1950 Overvoltage Tests
C8
FB1
FB2
C9
RV1
Fuse/PTC
TIP
RING
1.25 A
1000 Ω @ 100 MHz, 200 mA
1000 Ω @ 100 MHz, 200 mA