Datasheet

 2018 Microchip Technology Inc. Data Sheet Complete DS40002058A-page 117
ATxmega128A1U/ATxmega64A1U
37.2.14.6 External clock characteristics
Figure 37-10. External clock drive waveform.
Table 37-61. External clock used as system clock without prescaling.
Note: 1. The maximum frequency vs. supply voltage is linear between 1.6V and 2.7V, and the same applies for all other parameters with supply voltage conditions.
Table 37-62. External clock with prescaler
(1)
for system clock.
Symbol Parameter Condition Min. Typ. Max. Units
1/t
CK
Clock Frequency
(1)
V
CC
= 1.6 - 1.8V 0 12
MHz
V
CC
= 2.7 - 3.6V 0 32
t
CK
Clock Period
V
CC
= 1.6 - 1.8V 83.3
ns
V
CC
= 2.7 - 3.6V 31.5
t
CH
Clock High Time
V
CC
= 1.6 - 1.8V 30.0
ns
V
CC
= 2.7 - 3.6V 12.5
t
CL
Clock Low Time
V
CC
= 1.6 - 1.8V 30.0
ns
V
CC
= 2.7 - 3.6V 12.5
t
CR
Rise Time (for maximum frequency)
V
CC
= 1.6 - 1.8V 10
ns
V
CC
= 2.7 - 3.6V 3
t
CF
Fall Time (for maximum frequency)
V
CC
= 1.6 - 1.8V 10
ns
V
CC
= 2.7 - 3.6V 3
t
CK
Change in period from one clock cycle to the next 10 %
Symbol Parameter Condition Min. Typ. Max. Units
1/t
CK
Clock Frequency
(2)
V
CC
= 1.6 - 1.8V 0 90
MHz
V
CC
= 2.7 - 3.6V 0 142
t
CK
Clock Period
V
CC
= 1.6 - 1.8V 11
ns
V
CC
= 2.7 - 3.6V 7
t
CH
Clock High Time
V
CC
= 1.6 - 1.8V 4.5
ns
V
CC
= 2.7 - 3.6V 2.4
t
CL
Clock Low Time
V
CC
= 1.6 - 1.8V 4.5
ns
V
CC
= 2.7 - 3.6V 2.4
t
CH
t
CL
t
CK
t
CH
V
IL1
V
IH1
t
CR
t
CF