ATMEGA644P-20AQ Atmel, ATMEGA644P-20AQ Datasheet - Page 330

• Manufacturer Part Number: ATMEGA644P-20AQ
• Description: MCU AVR 64K FLASH 20MHZ 44-TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA644P-20AQ

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

25.3
Table 25-4.
Notes:
25.3.1
25.3.2
Table 25-5.
8011O–AVR–07/10
Factory
Calibration
User
Calibration
Symbol
1/t
t
t
t
t
t
Δ
CLCL
CHCX
CLCX
CLCH
CHCL
t
CLCL
CLCL
Clock Characteristics
1. Voltage range for ATmega164PV/324PV/644PV.
2. Voltage range for ATmega164P/324P/644P.
External Clock Drive Waveforms
External Clock Drive
Calibration Accuracy of Internal RC Oscillator
External Clock Drive
Parameter
Oscillator Frequency
Clock Period
High Time
Low Time
Rise Time
Fall Time
Change in period from
one clock cycle to the
next
Figure 25-3. External Clock Drive Waveforms
7.3 MHz - 8.1 MHz
Frequency
8.0 MHz
V
V
Min.
IL1
250
100
100
CC
0
V
IH1
= 1.8V - 5.5V
1.8V - 5.5V
2.7V - 5.5V
Max.
2.0
2.0
4
2
V
3V
CC
(1)
(2)
Min.
V
100
40
40
0
CC
= 2.7V - 5.5V
ATmega164P/324P/644P
Max.
Temperature
-40°C - 85°C
1.6
1.6
10
2
25°C
V
Min.
50
20
20
CC
0
= 4.5V - 5.5V
Calibration Accuracy
Max.
0.5
0.5
20
2
±10%
±1%
Units
MHz
ns
μs
%
330