Manual

101
AT90S/LS4433
1042G–AVR–09/02
Typical
Characteristics
The following charts show typical behavior. These figures are not tested during manu-
facturing. All current consumption measurements are performed with all I/O pins
configured as inputs and with internal pull-ups enabled. A sine wave generator with rail-
to-rail output is used as clock source.
The power consumption in Power-down mode is independent of clock selection.
The 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.
The current drawn from capacitive loaded pins may be estimated (for one pin) as
C
L
• V
CC
• f, where C
L
= load capacitance, V
CC
= operating voltage and f = average
switching frequency of I/O pin.
The parts are characterized at frequencies higher than test limits. Parts are not guaran-
teed to function properly at frequencies higher than the ordering code indicates.
The difference between current consumption in Power-down mode with Watchdog
Timer enabled and Power-down mode with Watchdog Timer disabled represents the dif-
ferential current drawn by the Watchdog Timer.
The difference between Power-down mode with Brown-out Detector enabled and
Power-down mode with Watchdog Timer disabled represents the differential current
drawn by the Brown-out Detector.
Figure 70. Active Supply Current vs. Frequency
0
5
10
15
20
25
30
35
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
ACTIVE SUPPLY CURRENT vs. FREQUENCY
T
A
= 25˚C
V
CC
= 6V
V
CC
= 5.5V
V
CC
= 5V
V
CC
= 4.5V
V
CC
= 4V
V
CC
= 3.6V
V
CC
= 3.3V
V
CC
= 3.0V
V
CC
= 2.7V
Frequency (MHz)
I
CC
(mA)