Datasheet

59
32099IS–01/2012
AT32UC3L016/32/64
7.8.6 Analog to Digital Converter Characteristics
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 Aquisition Time
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.
An analog voltage input 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 resistor
( ) and a capacitor ( ). In addition the resistance ( ) and capacitance
( ) of the PCB and source must be taken into account when calculating the sample and
hold time. Figure 7-7 shows the ADC input channel equivalent circuit.
Table 7-28. ADC Characteristics
Symbol Parameter Conditions Min Typ Max Units
f
ADC
ADC clock frequency
10-bit resolution mode 6
MHz
8-bit resolution mode 6
t
STARTUP
Startup time Return from Idle Mode 15 µs
t
CONV
Conversion time (latency) f
ADC
= 6MHz 11 26 cycles
Throughput rate
V
VDD
> 3.0V, f
ADC
= 6MHz,
10-bit resolution mode,
low impedance source
460
kSPS
V
VDD
> 3.0V, f
ADC
= 6MHz,
8-bit resolution mode,
low impedance source
460
V
ADVREFP
Reference voltage range V
ADVREFP
= V
VDDANA
1.62 1.98 V
I
ADC
Current consumption on V
VDDANA
ADC Clock = 6MHz 300
µA
I
ADVREFP
Current consumption on ADVREFP
pin
f
ADC
= 6MHz 250
Table 7-29. Analog Inputs
Symbol Parameter Conditions Min Typ Max Units
V
ADn
Input Voltage Range
10-bit mode
0V
ADVREFP
V
8-bit mode
C
ONCHIP
Internal Capacitance
(1)
21.5 pF
R
ONCHIP
Internal Resistance
(1)
V
VDDIO
= 3.0V to 3.6V,
V
VDDCORE
= 1.8V
2.55
kOhm
V
VDDIO
= V
VDDCORE
= 1.62V to 1.98V 55.3
R
ONCHIP
C
ONCHIP
R
SOURCE
C
SOURCE