C509-L_97 Datasheet, PDF (195/290 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

On-Chip Peripheral Components
C509-L
Table 6-14
Limit Values for the impedance of the Analog Source at f_OSC = 16 MHz (C_IN = 50pF)
Conversion Clock
Prescaler
ADCL1 ADCL0
0
0
0
1
1
0
1
1
Sample Clock
Prescaler
ADST1 ADST0
0
0
0
1
1
0
1
1
0
0
0
1
1
0
1
1
0
0
0
1
1
0
1
1
0
0
0
1
1
0
1
1
Sample Time
(16 MHz)
t _S [µs]
0.5
1
2
4
1
2
4
8
2
4
8
16
4
8
16
32
Impedance R_MAX [kΩ]
at 16MHz
Error
1 LSB
2 LSB
–
–
–
–
–
–
–
–
2.9
3.2
5.8
6.4
11.6
12.9
23.1
25.7
5.8
6.4
11.6
12.9
23.1
25.7
46.3
51.5
11.6
12.9
23.1
25.7
46.3
51.5
92.6
103
Note : The shaded prescaler combination can only be used up to f_OSC = 8 MHz.
Reason : f_ADC > 2 MHz for f_OSC > 8 MHz.
The values in table 6-14 are just calculated values and are no assured limit characteristics.
System environment and application dependencies must be taken into account, too.
Semiconductor Group
6-117
1997-10-01