Datasheet

719
11011B–ATARM–21-Feb-12
SAM3N
.
Note: 1. Input Voltage range can be up to VDDIN without destruction or over-consumption.
If VDDIO < V
ADVREF
, max input voltage is VDDIO.
35.6.0.3 Track and Hold Time versus Source Output Impedance
The following figure gives a simplified acquisition path.
Figure 35-11. Simplified Acquisition Path
The user can drive ADC input with impedance of Zsource up to:
• In 8-bit mode: TRACKTIM = 0.1 x Zsource + 470
• In 10-bit mode: TRACKTIM = 0.13 x Zsource + 589
with TRACKTIM (Track and Hold Time register) expressed in ns and Zsource expressed in
ohms.
Note: Csample and Ron are taken into account in the formulas
35.6.0.4 ADC Application Information
For more information on data converter terminology, please refer to the application note:
Data Converter Terminology, Atmel lit° 6022.
http://www.atmel.com/dyn/resources/prod_documents/doc6022.pdf
Table 35-33. External Voltage Reference Input
Parameter Conditions Min Typ Max Units
ADVREF Input Voltage Range 2.6 V
DDIN
V
ADVREF Input Voltage Range 8-bit resolution mode 2.5 V
DDIN
V
ADVREF Average Current On 13 samples with ADC Clock = 5 MHz 200 250 µA
Table 35-34. Analog Inputs
Parameter Min Typ Max Units
Input Voltage Range 0V
ADVREF
Input Leakage Current ±1 µA
Input Capacitance 12 14 pF
Sample & HoldMux.
Zsource Ron
Csample
ADC
Input
10-bit
ADC
Core