Datasheet

M16C/6S Group IT800AFE (Analog Front End)
R01DS0201EJ0502 Rev.5.02 page 186 of 203
Dec 25, 2012
IT800AFE (Analog Front End)
1. The block diagram of analog front end
Analog front end (AFE) part is the circuit located between M16C/6S and a power line, and M16C/6S
build in DAC, preamplifier, and ADC. There are the following two signal circuits in AFE.
(1)Transmitting circuit:It drives with the signal from the logic of M16C/6S inside, and this is consists of
DAC with a differential output, Output filter for spectrum adjustment, Differential line driver amplifier and
line coupling circuit which drive power line.
(2)Receiving circuit:This is consists of Line coupling circuit, Differential preamplifier, Input filter group
and ADC. Line coupling circuit is common to both transmission and reception.
(1)Transmitting path
The characteristics required for transmitting path are as follows.
(a)A suitable output signal level is obtained on specific load.
(b)Frequency characteristic is flat in signal bandwidth.
(c)The signal level outside a zone: It is less than each regulation.
This system assumes operation in the following three fundamental signal zones.
(a)The U.S., Japan: 120k to 400kHz
(b)Europe in door: 95k to 125kHz(CENELEC B Band)
(c)Europe out door: 20k to 80kHz(CENELEC A Band)
It is necessary to perform the change of a signal zone by change of adjustment of change of the
configuration of IT800, the analog filter to a signal zone, or output electric power, and the output imped-
ance of the line driver stage (notes).
Note. Please refer to the following standard and style about the conditions outside a signal level or a
zone.
(a)The U.S.:FCC standard, part 15
(b)Europe:CENELEC standard, EN 50065-1
(c)Japan:ARIB STD-T84
M16C/6S
Output
Filter
Input Filter
Pre
Amp
Channel
Filters
Line
Driver
Power line
Line
Driver
DAC
ADC
Figure 1.23.1 Analog Front End circuit block diagram