302
4317I–AVR–01/08
AT90PWM2/3/2B/3B
5. Minimum V
CC
for Power-down is 2.5V.
6. The Analog Comparator Propogation Delay equals 1 comparator clock plus 30 nS.
See “Analog Comparator” on page 227.
for comparator clock definition.
26.3
External Clock Drive Characteristics
26.3.1
Calibrated Internal RC Oscillator Accuracy
26.3.2
External Clock Drive Waveforms
Figure 26-1. External Clock Drive Waveforms
26.3.3
External Clock Drive
Table 26-1.
Calibration Accuracy of Internal RC Oscillator
Frequency
V
CC
Temperature Calibration
Accuracy
Factory
Calibration
8.0 MHz
3V
25
°
C
±10%
User
Calibration
7.3 - 8.1 MHz
2.7V - 5.5V
-40
°
C - 85
°
C
±1%
V
IL1
V
IH1
Table 26-2.
External Clock Drive
Symbol
Parameter
V
CC
=1.8-5.5V
V
CC
=2.7-5.5V
V
CC
=4.5-5.5V
Units
Min.
Max.
Min.
Max.
Min.
Max.
1/t
CLCL
Oscillator
Frequency
0
4
0
10
0
20
MHz
t
CLCL
Clock Period
250
100
50
ns
t
CHCX
High Time
100
40
20
ns
t
CLCX
Low Time
100
40
20
ns
t
CLCH
Rise Time
2.0
1.6
0.5
μ
s
t
CHCL
Fall Time
2.0
1.6
0.5
μ
s
Δ
t
CLCL
Change in period
from one clock
cycle to the next
2
2
2
%
