XC228X Datasheet, PDF (88/110 Pages) Infineon Technologies AG – 16/32-Bit Single-Chip Microcontroller with 32-Bit Performance

XC2287 / XC2286 / XC2285
XC2000 Family Derivatives
Preliminary
Electrical Parameters
Sample time and conversion time of the XC228x’s A/D Converters are programmable.
The above timing can be calculated using Table 16.
The limit values for f_ADCI must not be exceeded when selecting the prescaler value.
Table 16 A/D Converter Computation Table
GLOBCTR.5-0
(DIVA)
000000_B
000001_B
000010_B
:
111110_B
111111_B
A/D Converter
Basic Clock f_ADCI
f_SYS
f_SYS / 2
f_SYS / 3
f_SYS / (DIVA+1)
f_SYS / 63
f_SYS / 64
INPCRx.7-0
(STC)
00_H
01_H
02_H
:
FE_H
FF_H
Sample Time
t_S
t_ADCI × 2
t_ADCI × 3
t_ADCI × 4
t_ADCI × (STC+2)
t_ADCI × 256
t_ADCI × 257
Converter Timing Example:
Assumptions: f_SYS
Basic clock
f_ADCI
Sample time
t_S
Conversion 10-bit:
t_C10
Conversion 8-bit:
t_C8
= 66 MHz (i.e. t_SYS = 15.2 ns), DIVA = 03_H, STC = 00_H
= f_SYS / 4 = 16.5 MHz, i.e. t_ADCI = 60.6 ns
= t_ADCI × 2 = 121 ns
= 17 × t_ADCI = 17 × 60.6 ns = 1.03 µs
= 15 × t_ADCI = 15 × 60.6 ns = 0.91 µs
Converter Timing Example:
Assumptions: f_SYS
Basic clock
f_ADCI
Sample time
t_S
Conversion 10-bit:
t_C10
Conversion 8-bit:
t_C8
= 40 MHz (i.e. t_SYS = 25 ns), DIVA = 02_H, STC = 03_H
= f_SYS / 3 = 13.3 MHz, i.e. t_ADCI = 75 ns
= t_ADCI × 5 = 375 ns
= 20 × t_ADCI = 20 × 75 ns = 1.5 µs
= 18 × t_ADCI = 18 × 75 ns = 1.35 µs
Data Sheet
86
V0.91, 2007-02
Draft Version