636
111
110
101
100
011
010
001
000
0 1/8 2/8 3/8 4/8 5/8 6/8 7/8 FS
Analog input
voltage
FS: Full-scale voltage
(3) Quantization
error
Ideal A/D
conversion
characteristic
(4) Nonlinearity
error
Ideal A/D
conversion
characteristic
Actual A/D
convertion
characteristic
(2) Full-scale error
Digital output
Analog input
voltage
(1) Offset error
FS
Digital output
Figure 20.8 Definitions of A/D Conversion Accuracy
20.7
Usage Notes
When using the A/D converter, note the following points.
20.7.1
Setting Analog Input Voltage
•
Analog Input Voltage Range: During A/D conversion, the voltages input to the analog input
pins ANn should be in the range AV
SS
≤
ANn
≤
AV
CC
(n = 0 to 7).
•
Relationships of AV
CC
and AV
SS
: AV
CC
and AV
SS
should be related as follows: AV
CC
= V
CC
± 0.3 V and AV
SS
= V
SS
.
20.7.2
Processing of Analog Input Pins
To prevent damage from voltage surges at the analog input pins (AN0 to AN7), connect an input
protection circuit like the one shown in figure 20.9. The circuit shown also includes an CR filter to
suppress noise. This circuit is shown as an example; the circuit constants should be selected
according to actual application conditions. Table 20.5 lists the analog input pin specifications and
figure 20.10 shows an equivalent circuit diagram of the analog input ports.
Содержание SH7709S
Страница 2: ...Hitachi SuperH RISC engine SH7709S Hardware Manual ADE 602 250 Rev 1 0 09 21 01 Hitachi Ltd ...
Страница 75: ...56 ...
Страница 107: ...88 ...
Страница 125: ...106 ...
Страница 139: ...120 ...
Страница 203: ...184 ...
Страница 245: ...226 ...
Страница 292: ...273 T1 CKIO A25 to A0 CSn RD WR RD D31 to D0 WEn D31 to D0 BS T2 Read Write Figure 10 6 Basic Timing of Basic Interface ...
Страница 323: ...304 Tp TRr TRrw TRrw CKIO CKE CSn RAS3U RAS3L CASU CASL RD WR Figure 10 28 Synchronous DRAM Auto Refresh Timing ...
Страница 411: ...392 ...
Страница 609: ...590 ...
Страница 635: ...616 ...
Страница 663: ...644 ...
Страница 679: ...660 ...