Datasheet

258
ATtiny828 [DATASHEET]
8371A–AVR–08/12
25. Typical Characteristics
The data contained in this section is largely based on simulations and characterization of similar devices in the same
process and design methods. Thus, the data should be treated as indications of how the part will behave.
The following charts show typical behavior. These figures are not tested during manufacturing. During characterisation
devices are operated at frequencies higher than test limits but they are not guaranteed to function properly at frequencies
higher than the ordering code indicates.
All current consumption measurements are performed with all I/O pins configured as inputs and with internal pull-ups
enabled. Current consumption is a function of several factors such as operating voltage, operating frequency, loading of
I/O pins, switching rate of I/O pins, code executed and ambient temperature. The dominating factors are operating
voltage and frequency.
A sine wave generator with rail-to-rail output is used as clock source but current consumption in Power-Down mode is
independent of clock selection. The difference between current consumption in Power-Down mode with Watchdog Timer
enabled and Power-Down mode with Watchdog Timer disabled represents the differential current drawn by the
Watchdog Timer.
The current drawn from pins with a capacitive load may be estimated (for one pin) as follows:
where V
CC
= operating voltage, C
L
= load capacitance and f
SW
= average switching frequency of I/O pin.
25.1 Current Consumption in Active Mode
Figure 109. Active Supply Current vs. Low Frequency (0.1 - 1.0 MHz)
I
CP
V
CC
C
L
f××
SW
≈
5.5 V
5.0 V
4.5 V
4.0 V
3.3 V
2.7 V
1.8 V
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1
0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1
Frequency [MHz]
I
CC
[mA]