ATmega168A Atmel Corporation, ATmega168A Datasheet - Page 30

• Manufacturer Part Number: ATmega168A
• Manufacturer: Atmel Corporation

Specifications of ATmega168A

• Flash (kbytes): 16 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 23
• Ext Interrupts: 24
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• 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: Yes
• Crypto Engine: No
• Sram (kbytes): 1
• Eeprom (bytes): 512
• 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: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

8271D–AVR–05/11
Figure 9-2.
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
on page
Table 9-3.
Notes:
The CKSEL0 Fuse together with the SUT1...0 Fuses select the start-up times as shown in
9-4.
Table 9-4.
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
1. This is the recommended CKSEL settings for the difference frequency ranges.
2. This option should not be used with crystals, only with ceramic resonators.
3. If the crystal frequency exceeds the specification of the device (depends on V
30.
8.0 - 16.0
0.4 - 0.9
0.9 - 3.0
3.0 - 8.0
(MHz)
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.
Crystal Oscillator Connections
Low Power Crystal Oscillator Operating Modes
Start-up Times for the Low Power Crystal Oscillator Clock Selection
ATmega48A/PA/88A/PA/168A/PA/328/P
Start-up Time from
Power-down and
C2
C1
Power-save
258 CK
258 CK
1K CK
1K CK
1K CK
Capacitors C1 and C2 (pF)
Recommended Range for
12 - 22
12 - 22
12 - 22
–
XTAL2 (TOSC2)
XTAL1 (TOSC1)
GND
Additional Delay
14CK + 4.1ms
14CK + 4.1ms
14CK + 65ms
14CK + 65ms
(V
from Reset
CC
14CK
= 5.0V)
(3)
(2)
(1)
(2)
(1)
(2)
CKSEL0
CKSEL3...1
0
0
0
0
1
CC
100
101
110
111
), the CKDIV8
(2)
Table 9-3
SUT1...0
(1)
00
01
10
11
00
Table
30