C515C_9711 Datasheet, PDF (186/268 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

On-Chip Peripheral Components
C515C
Note : The prescaler ratios in table 6-8 are minimum values. At system clock rates (f_OSC) up to
8 MHz the divider ratio 4 and 8 can be used. At system clock rates greater than 8 MHz
divider ratio 8 must be used. Using higher divider ratios than required increases the total
conversion time but can be useful in applications which have voltage sources with higher
input resistances for the analog inputs (increased sample phase).
t _ADCC
µs
30
20
t _{ADCCmin = 6 µs}
10
6
Prescaler ÷ 4
Prescaler ÷ 8
1
2
3
4
5
6
7
8
9
10 MHz
f _OCS
MCD02751
Figure 6-56
Minimum A/D Conversion Time in Relation to System Clock
Semiconductor Group
6-123
1997-11-01