Datasheet

32.3.2. External Clock Drive
Table 32-3 External Clock Drive
(1)
Symbol Parameter V
CC
= 2.7V to 5.5V V
CC
= 4.5V to 5.5V Units
Min Max Min Max
1/t
CLCL
Oscillator Frequency 0 8 0 16 MHz
t
CLCL
Clock Period 125 62.5 ns
t
CHCX
High Time 50 25 ns
t
CLCX
Low Time 50 25 ns
t
CLCH
Rise Time 1.6 0.5 μs
t
CHCL
Fall Time 1.6 0.5 μs
Δt
CLCL
Change in period from one clock cycle to the
next
2 2 %
Note: 1. Refer to External Clock for details.
Table 32-4 External RC Oscillator, Typical Frequencies
R [kΩ]
(1)
C [pF] f
(2)
31.5 20 650kHz
6.5 20 2.0MHz
Note:
1. R should be in the range 3kΩ - 100kΩ, and C should be at least 20pF. The C values given in the
table includes pin capacitance. This will vary with package type.
2. The frequency will vary with package type and board layout.
32.4. System and Reset Characteristics
Table 32-5 Reset, Brown-out and Internal Voltage Reference Characteristics
Symbol Parameter Condition Min Typ Max Units
V
POT
Power-on Reset Threshold Voltage (rising)
(1)
1.4 2.3 V
Power-on Reset Threshold Voltage (falling) 1.3 2.3 V
V
RST
RESET Pin Threshold Voltage 0.2V
CC
0.85V
CC
V
t
RST
Pulse width on RESET Pin 1.5 μs
V
BOT
Brown-out Reset Threshold Voltage
(2)
BODLEVEL = 0 3.6 4.0 4.2 V
BODLEVEL = 1 2.5 2.7 2.9 V
t
BOD
Minimum low voltage period for Brown-out
Detection
BODLEVEL = 0 2 μs
BODLEVEL = 1 2 μs
V
HYST
Brown-out Detector hysteresis 120 mV
Atmel ATmega64A [DATASHEET]
Atmel-8160E-ATmega64A_Datasheet_Complete-09/2015
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