Atmel Xplained Pro Evaluation Kit ATSAM4E-XPRO ATSAM4E-XPRO Data Sheet
Product codes
ATSAM4E-XPRO
1445
SAM4E [DATASHEET]
Atmel-11157D-ATARM-SAM4E16-SAM4E8-Datasheet_12-Jun-14
Note:
1.
N/A: Not applicable
Track and Hold Time versus Source Output Impedance
shows a simplified acquisition path.
Figure 47-18. Simplified Acquisition Path
During the tracking phase, the ADC needs to track the input signal during the tracking time shown below:
t
TRACK
= 0.054 x Z
SOURCE
+ 205
with t
TRACK
expressed in ns and Z
SOURCE
expressed in
Ω
.
The ADC already includes a tracking time of 15 t
CP_ADC
Two cases must be considered:
1.
If the calculated tracking time (t
TRACK
) is lower than 15 t
CP_ADC
, then TRACTIM can be set to 0 .
If the calculated tracking time (t
TRACK
) is higher than 15 t
CP_ADC
, then TRACTIM must be set to the correct value.
47.7.5.4 AFE DAC Offset Compensation
1
2 pF
4 pF
2
2 pF
8 pF
4
4 pF
N/A
Table 47-44.
Z
IN
Input Impedance
f
S
(MHz)
1
0.5
0.25
0.125
0.0625
0.03125
0.015625
0.007813
C
IN
= 2 pF
Z
IN
(M
Ω)
0.5
1
2
4
8
16
32
64
C
IN
= 4 pF
Z
IN
(M
Ω)
0.25
0.5
1
2
4
8
16
32
C
IN
= 8 pF
Z
IN
(M
Ω)
0.125
0.25
0.5
1
2
4
8
16
Table 47-43.
Input Capacitance (C
IN
) Values
Sample & Hold
12-bit ADC Core
C
IN
MUX
R
ON
Z
SOURCE
Table 47-45.
AFE DAC Offset Compensation
Parameter
Conditions
Min
Typ
Max
Units
Resolution - N
—
—
12
—
bits