ATmega649A Atmel Corporation, ATmega649A Datasheet - Page 34

• Manufacturer Part Number: ATmega649A
• Manufacturer: Atmel Corporation

Specifications of ATmega649A

• Flash (kbytes): 64 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 54
• Ext Interrupts: 17
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Segment Lcd: 100
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 4
• Eeprom (bytes): 2048
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

9.6
8284D–AVR–6/11
Low-frequency Crystal Oscillator
ATmega169A/PA/329A/PA/3290A/PA/649A/P/6490A/P
Table 9-6.
Notes:
The Low-frequency Crystal Oscillator is optimized for use with a 32.768kHz watch crystal. When
selecting crystals, load capacitance and crystal’s Equivalent Series Resistance, ESR must be
taken into consideration. Both values are specified by the crystal vendor.
ATmega329A/329PA oscillator is optimized for very low power consumption, and thus when
selecting crystals, see
crystals
Table 9-7.
Note:
The Low-frequency Crystal Oscillator provides an internal load capacitance, see
page 35
ATmega169A/169PA/329A/329PA/649A/649P/3290A/3290PA/6490A/6490P oscillator is opti-
mized for very low power consumption, and thus when selecting crystals, see
34
Table 9-8.
Note:
CKSEL0
for maximum ESR recommendations on 6.5pF, 9.0pF and 12.5pF crystals.
1
1
1
1. These options should only be used when not operating close to the maximum frequency of the
2. These options are intended for use with ceramic resonators and will ensure frequency stability
1. Maximum ESR is typical value based on characterization
1. Maximum ESR is typical value based on characterization
at each TOSC pin.
device, and only if frequency stability at start-up is not important for the application. These
options are not suitable for crystals.
at start-up. They can also be used with crystals when not operating close to the maximum fre-
quency of the device, and if frequency stability at start-up is not important for the application.
SUT1..0
Start-up Times for the Crystal Oscillator Clock Selection (Continued)
Maximum ESR Recommendation for 32.768kHz Watch Crystal
ATmega169A/169PA
Maximum ESR Recommendation for 32.768kHz Watch Crystal
ATmega329A/329PA/3290A/3290PA/649A/649P/6490A/6490P
01
10
11
Crystal CL (pF)
Crystal CL (pF)
12.5
6.5
9.0
6.5
9
Table 9-7
Start-up Time from
Power-down and
Power-save
16K CK
16K CK
16K CK
for maximum ESR recommendations on 9pF and 6.5pF
Additional Delay
14CK + 4.1ms
14CK + 65ms
(V
from Reset
CC
14CK
= 5.0V)
Max ESR [kΩ]
Max ESR [kΩ]
75
65
30
60
35
Crystal Oscillator, BOD
enabled
Crystal Oscillator, fast
rising power
Crystal Oscillator,
slowly rising power
Recommended Usage
Table 9-8 on page
(1)
(1)
Table 9-9 on
34