Atmel ARM-Based Evaluation Kit for SAM4S16C, 32-Bit ARM® Cortex® Microcontroller ATSAM4S-WPIR-RD ATSAM4S-WPIR-RD Scheda Tecnica
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ATSAM4S-WPIR-RD
SAM4S Series [DATASHEET]
Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14
1154
44.8.2 External Reference Voltage
V
ADVREF
is an external reference voltage applied on the pin ADVREF. The quality of the reference voltage V
ADVREF
is critical to the performance of the ADC. A DC variation of the reference voltage V
ADVREF
is converted to a gain
error by the ADC. The noise generated by V
ADVREF
is converted by the ADC to count noise.
Notes: 1. See
.
2. Over a bandwidth from 20 Hz to 20 MHz.
3. DIFF is Differential mode.
4. SE is Single-ended mode.
5. When the ADC is in Sleep mode, the ADVREF impedance has a minimum of 10 MΩ.
3. DIFF is Differential mode.
4. SE is Single-ended mode.
5. When the ADC is in Sleep mode, the ADVREF impedance has a minimum of 10 MΩ.
44.8.3 ADC Timings
Table 44-38.
ADVREF Electrical Characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
V
ADVREF
ADVREF voltage range
Full operational
2.4
—
3.6
V
2
—
2.4
V
N
Input voltage noise
Gain = 0.5, DIFF
mode
—
—
1100
µVrms
Gain = 1, SE
and DIFF
—
—
550
Gain = 2, SE
and DIFF
—
—
274
Gain = 4, SE
mode
—
—
137
R
ADVREF
ADVREF Input DC
Impedance
ADC reference resistor bridge
6
8
10
kΩ
Table 44-39.
ADC Timing Characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
f
ADC
Clock Frequency
1
20
22
MHz
t
CP_ADC
Clock Period
45
50
1000
ns
f
S
Sampling Frequency
0.05
1
1.1
MHz
t
START-UP
ADC Startup time
Sleep mode to Normal mode
Fast Wake-up mode to Normal mode
Fast Wake-up mode to Normal mode
20
4
30
8
40
12
12
µs
t
TRACKTIM
Track Time
f
ADC
= max value
160
—
—
ns
t
CONV
Conversion Time
Number of ADC clock pulses to
perform a conversion
—
20
—
T
CP_ADC
t
SETTLE
Settling Time
Settling time to change offset and gain
100
—
—
ns
t
CAL
Calibration time
200
—
—
ns