Manual

107
AT90S/LS8535
1041H–11/01
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 switch-
ing 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 with Watchdog Timer enabled and
Power-down mode with Watchdog Timer disabled represents the differential current
drawn by the Watchdog Timer.
Figure 75. Active Supply Current vs. Frequency
ACTIVE SUPPLY CURRENT vs. FREQUENCY
T = 25˚C
A
Frequency (MHz)
I
cc
(mA)
V
cc
= 5.5V
V
cc
= 5V
0
5
10
15
20
25
30
35
40
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
V
cc
= 2.7V
V
cc
= 3.0V
V
cc
= 3.3V
V
cc
= 3.6V
V
cc
= 4V
V
cc
= 4.5V
V
cc
= 6V