ATMEGA644PV-20AU Atmel, ATMEGA644PV-20AU Datasheet - Page 37
![IC MCU AVR 64K FLASH 44-TQFP](/photos/6/70/67042/313-44-tqfp_sml.jpg)
ATMEGA644PV-20AU
Manufacturer Part Number
ATMEGA644PV-20AU
Description
IC MCU AVR 64K FLASH 44-TQFP
Manufacturer
Atmel
Series
AVR® ATmegar
Specifications of ATMEGA644PV-20AU
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-TQFP, 44-VQFP
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
- Current page: 37 of 439
- Download datasheet (10Mb)
6.7
6.8
8011O–AVR–07/10
128 kHz Internal Oscillator
External Clock
The 128 kHz internal Oscillator is a low power Oscillator providing a clock of 128 kHz. The fre-
quency is nominal at 3V and 25°C. This clock may be select as the system clock by
programming the CKSEL Fuses to “0011” as shown in
Table 6-12.
Note:
When this clock source is selected, start-up times are determined by the SUT Fuses as shown in
Table
Table 6-13.
To drive the device from an external clock source, XTAL1 should be driven as shown in
6-3. To run the device on an external clock, the CKSEL Fuses must be programmed to “0000”.
Figure 6-3.
When this clock source is selected, start-up times are determined by the SUT Fuses as shown in
Table
Table 6-14.
BOD enabled
Fast rising power
Slowly rising power
Power Conditions
6-13.
6-15.
1. Note that the 128 kHz oscillator is a very low power clock source, and is not designed for high
accuracy.
128 kHz Internal Oscillator Operating Modes
Start-up Times for the 128 kHz Internal Oscillator
External Clock Drive Configuration
Crystal Oscillator Clock Frequency
Nominal Frequency
Nominal Frequency
0 - 20 MHz
EXTERNAL
128 kHz
SIGNAL
CLOCK
Start-up Time from Power-
down and Power-save
NC
Reserved
6 CK
6 CK
6 CK
ATmega164P/324P/644P
XTAL2
XTAL1
GND
Table
(2)
Additional Delay from
6-12.
14CK + 64 ms
14CK + 4 ms
Reset
14CK
CKSEL3..0
CKSEL3..0
0011
0000
SUT1..0
00
01
10
11
Figure
37
Related parts for ATMEGA644PV-20AU
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
![ATmega644P](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
![ATmega644P Automotive](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
![ATMEGA644P-20AU](/photos/6/70/67042/313-44-tqfp_tmb.jpg)
Part Number:
Description:
IC MCU AVR 64K FLASH 44-TQFP
Manufacturer:
Atmel
Datasheet:
![ATMEGA644P-20MU](/photos/12/13/121316/313-44-qfn_tmb.jpg)
Part Number:
Description:
IC MCU AVR 64K FLASH 44-QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA644P-20AQ](/photos/6/70/67042/313-44-tqfp_tmb.jpg)
Part Number:
Description:
MCU AVR 64K FLASH 20MHZ 44-TQFP
Manufacturer:
Atmel
Datasheet:
![ATMEGA644P-A15MZ](/photos/12/13/121316/313-44-qfn_tmb.jpg)
Part Number:
Description:
MCU AVR 64KB FLASH 16MHZ 44QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA644P-20PU](/photos/6/70/67049/453-40-dip_tmb.jpg)
Part Number:
Description:
IC MCU AVR 64K FLASH 40-DIP
Manufacturer:
Atmel
Datasheet:
![ATMEGA644P-20AUR](/images/manufacturer_photos/0/0/78/atmel_tmb.jpg)
Part Number:
Description:
MCU AVR 64K FLASH 20MHZ 44TQFP
Manufacturer:
Atmel
Datasheet:
![ATMEGA644P-20MUR](/images/manufacturer_photos/0/0/78/atmel_tmb.jpg)
Part Number:
Description:
MCU AVR 64K FLASH 20MHZ 44QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA644P-20MQ](/photos/12/13/121316/313-44-qfn_tmb.jpg)
Part Number:
Description:
MCU AVR 64K FLASH 20MHZ 44-QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA644P-20PQ](/photos/6/70/67049/453-40-dip_tmb.jpg)
Part Number:
Description:
MCU AVR 64K FLASH 20MHZ 40-PDIP
Manufacturer:
Atmel
Datasheet: