SAM4C_14 Datasheet, PDF (1247/1303 Pages) ATMEL Corporation – Atmel | SMART ARM-based Flash MCU

46.5.18 Programmable Voltage Reference Characteristics
The SAM4C embeds a programmable voltage reference designed to drive the 10-bit ADC ADVREF input. Table
46-41 shows the electrical characteristics of this internal voltage reference. If necessary, this voltage reference can
be bypassed with some level of configurability: the user can either choose to feed the ADVREF input with an
external voltage source or with the VDDIO internal power rail. See programming details in the ADC Analog Control
Register (ADC_ACR) in the section Analog-to-Digital Converter (ADC) in this datasheet.
Table 46-41. Programmable Voltage Reference Characteristics
Symbol Parameter
Conditions
Min
Typ
Max
Unit
V_DDIN
Voltage reference supply range
V_ADVREF Programmable output range
–
See Table 46-42.
V_DDIN > V_ADVREF + 100mV
2.4
–
3.6
V
1.6
–
3.4
V
ACC
T_C
t_ON
Reference voltage accuracy
Temperature coefficient
Start-up time
Z_LOAD
Load impedance
With respect to the programmed value.
V_DDIN = 3.3V; T_J = 25°C
-3
Box method⁽¹⁾
–
–
3
%
–
250
ppm/°C
V_DDIN = 2.4V
V_DDIN = 3V
V_DDIN = 3.6V
Resistive
100
–
–
70
µs
40
4
–
–
kΩ
Capacitive
0.1
–
1
µF
I_VDDIN
Current consumption on VDDIN⁽²⁾
ADC is OFF
–
20
30
µA
Notes: 1. T_C = ( max(V_ADVREF) - min(V_ADVREF) ) / ( (T_MAX - T_MIN) * V_ADVREF(25°C) ).
2. Does not include the current consumed by the ADC ADVREF input if ADC is ON.
Table 46-42. Programmable Voltage Reference Selection Values
Sel. Value⁽¹⁾
ADVREF
Notes
0
2.40
Default value
1
2.28
–
2
2.16
–
3
2.04
–
4
1.92
–
5
1.80
–
6
1.68
–
7
1.55
Min value
8
3.38
Max value
9
3.25
–
A
3.13
–
B
3.01
–
C
2.89
–
D
2.77
–
E
2.65
–
F
2.53
–
Note: 1. Voltage reference values are configurable in the ADC_ACR.IRVS.
SAM4C Series [DATASHEET]
Atmel-11102E-ATARM-SAM4C32-SAM4C16-SAM4C8-Datasheet_06-Oct-14
1247