AT32UC3L0256-D3HT Datasheet, PDF (59/96 Pages) ATMEL Corporation – 32-bit Atmel AVR Microcontroller

AT32UC3L0128/256
7.8.6 Analog to Digital Converter Characteristics
Table 7-28. ADC Characteristics
Symbol Parameter
f_ADC
ADC clock frequency
f_ADC
ADC clock frequency
t_STARTUP
t_CONV
Startup time
Conversion time (latency)
Throughput rate
Throughput rate
V_ADVREFP
I_ADC
I_ADVREFP
Reference voltage range
Current consumption on V_VDDANA
Current consumption on ADVREFP
pin
Conditions
12-bit resolution mode
10-bit resolution mode
8-bit resolution mode
Return from Idle Mode
f_ADC = 6MHz
V_VDD > 3.0V, f_ADC = 6MHz,
12-bit resolution mode,
low impedance source
V_VDD > 3.0V, f_ADC = 6MHz,
10-bit resolution mode,
low impedance source
V_VDD > 3.0V, f_ADC = 6MHz,
8-bit resolution mode,
low impedance source
V_ADVREFP = V_VDDANA
ADC Clock = 6MHz
f_ADC = 6MHz
Min
Typ
Max
Units
6
MHz
6
MHz
6
15
µs
11
26
cycles
28
kSPS
460
kSPS
460
1.62
1.98
V
350
µA
150
Note: These values are based on simulation and characterization of other AVR microcontrollers manufactured in the same process
technology. These values are not covered by test limits in production.
7.8.6.1
Inputs and Sample and Hold Acquisition Times
Table 7-29. Analog Inputs
Symbol Parameter
V_ADn
Input Voltage Range
C_ONCHIP
Internal Capacitance⁽¹⁾
R_ONCHIP
Internal Resistance⁽¹⁾
Conditions
Min
Typ
Max
Units
12-bit mode
10-bit mode
8-bit mode
0
V_ADVREFP
V
22.5
pF
V_VDDIO = 3.0V to 3.6V,
V_VDDCORE = 1.8V
V_VDDIO = V_VDDCORE = 1.62V to 1.98V
3.15
kOhm
55.9
Note: 1. These values are based on simulation and characterization of other AVR microcontrollers manufactured in the same pro-
cess technology. These values are not covered by test limits in production.
The analog voltage source must be able to charge the sample and hold (S/H) capacitor in the
ADC in order to achieve maximum accuracy. Seen externally the ADC input consists of a resis-
tor ( R_ONCHIP ) and a capacitor ( C_ONCHIP ). In addition, the resistance ( R_SOURCE ) and capacitance
( C_SOURCE ) of the PCB and source must be taken into account when calculating the required
sample and hold time. Figure 7-7 shows the ADC input channel equivalent circuit.
59
32145BS–01/2012