ATMEGA644PA-MUR Atmel, ATMEGA644PA-MUR Datasheet - Page 33
ATMEGA644PA-MUR
Manufacturer Part Number
ATMEGA644PA-MUR
Description
IC MCU AVR 64K FLASH 44VQFN
Manufacturer
Atmel
Series
AVR® ATmegar
Specifications of ATMEGA644PA-MUR
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)
1.8 V ~ 5.5 V
Data Converters
A/D 8x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
44-VQFN Exposed Pad
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
- Current page: 33 of 581
- Download datasheet (27Mb)
8.3
8272A–AVR–01/10
Low Power Crystal Oscillator
This Crystal Oscillator is a low power oscillator, with reduced voltage swing on the XTAL2 out-
put. It gives the lowest power consumption, but is not capable of driving other clock inputs, and
may be more susceptible to noise in noisy environments. In these cases, refer to the
Crystal Oscillator” on page
Some initial guidelines for choosing capacitors for use with crystals are given in
crystal should be connected as described in
The Low Power Oscillator can operate in three different modes, each optimized for a specific fre-
quency range. The operating mode is selected by the fuses CKSEL3..1 as shown in
Table 8-3.
Notes:
The CKSEL0 Fuse together with the SUT1..0 Fuses select the start-up times as shown in
8-4.
Table 8-4.
164A/164PA/324A/324PA/644A/644PA/1284/1284P
Oscillator Source /
Power Conditions
Ceramic resonator, fast
rising power
Ceramic resonator, slowly
rising power
Ceramic resonator, BOD
enabled
Ceramic resonator, fast
rising power
Ceramic resonator, slowly
rising power
Frequency Range (MHz)
1. If the crystal frequency exceeds the specification of the device (depends on V
2. This is the recommended CKSEL settings for the different frequency ranges.
3. This option should not be used with crystals, only with ceramic resonators.
Fuse can be programmed in order to divide the internal frequency by 8. It must be ensured
that the resulting divided clock meets the frequency specification of the device.
8.0 - 16.0
0.4 - 0.9
0.9 - 3.0
3.0 - 8.0
Low Power Crystal Oscillator Operating Modes
Start-up Times for the Low Power Crystal Oscillator Clock Selection
34.
Start-up Time from
Power-down and
Power-save
258 CK
258 CK
1K CK
1K CK
1K CK
CKSEL3..1
100
101
110
111
”Clock Source Connections” on page
(3)
(2)
Additional Delay
14CK + 4.1 ms
14CK + 4.1 ms
Recommended Range for Capacitors C1
14CK + 65 ms
14CK + 65 ms
(V
from Reset
CC
14CK
= 5.0V)
(1)
(2)
(1)
(2)
(1)
(2)
and C2 (pF)
12 - 22
12 - 22
12 - 22
–
CKSEL0
0
0
0
0
1
CC
Table
32.
), the CKDIV8
Table
”Full Swing
SUT1..0
8-3. The
00
01
10
11
00
Table
8-3.
33
Related parts for ATMEGA644PA-MUR
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
Part Number:
Description:
IC AVR MCU FLASH 64K 44-QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU FLASH 64K 44TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU FLASH 64K 40DIP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU AVR 64K FLASH 20MHZ 44TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU AVR 64K FLASH 20MHZ 44QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
Atmega644 8-bit Avr Microcontroller With 64k Bytes In-system Programmable Flash
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
Part Number:
Description:
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
IC AVR MCU 64K 16MHZ 5V 64TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU 64K 16MHZ 5V 64-QFN
Manufacturer:
Atmel
Datasheet: