ATSAM3S-EK Atmel, ATSAM3S-EK Datasheet - Page 1062

• Manufacturer Part Number: ATSAM3S-EK
• Description: KIT EVAL FOR ATSAM3S4C
• Manufacturer: Atmel
• Series: SAM3Sr
• Type: MCUr

Specifications of ATSAM3S-EK

• Contents: Board, Cables, Power Supply
• Silicon Manufacturer: Atmel
• Core Architecture: ARM
• Core Sub-architecture: Cortex-M3
• Kit Contents: Board
• Features: TFT Colour LCD Display, SD/MMC Interface
• Svhc: No SVHC (15-Dec-2010)
• Rohs Compliant: Yes
• For Use With/related Products: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

41.7.0.1
1062
SAM3S Preliminary
Track and Hold Time versus Source Output Impedance
The following figure gives a simplified acquisition path.
Figure 41-12. Simplified Acquisition Path
During the tracking phase the ADC needs to track the input signal during the tracking time
shown below:
With t
Two cases must be considered:
Set TRANSFER = 1 and TRACTIM = 0.
In this case, the allowed Zsource can be computed versus the ADC frequency with the hypothe-
sis of t
Where t
f
20.00
16.00
10.67
8.00
6.40
5.33
4.57
4.00
3.56
3.20
2.91
2.67
2.46
2.29
2.13
2.00
1.00
• 10-bit mode: t
• 12-bit mode: t
1. The calculated tracking time (t
ADC
TRACK
= ADC clock (MHz)
TRACK
CP_ADC
expressed in ns and Z
= 15 × t
= 1/f
TRACK
TRACK
ADC
CP_ADC
.
Zsource
= 0.042 x Zsource + 160
= 0.054 x Zsource + 205
:
Z
Input
ADC
SOURCE
10
14
22
31
40
48
57
66
74
83
92
100
109
118
126
135
274
SOURCE
TRACK
expressed in Ohms.
(kOhms) for 12 bits
Mux.
Ron
) is lower than 15 t
Sample & Hold
Csample
CP_ADC
Z
14
19
30
41
52
63
74
85
97
108
119
130
141
152
164
175
353
SOURCE
.
12-bit
ADC
Core
(kOhms) for 10 bits
6500C–ATARM–8-Feb-11