ATmega168A Atmel Corporation, ATmega168A Datasheet - Page 257

no-image

ATmega168A

Manufacturer Part Number
ATmega168A
Description
Manufacturer
Atmel Corporation
Datasheets

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

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
ATmega168A-AU
Manufacturer:
ATMEL
Quantity:
464
Part Number:
ATmega168A-AU
Manufacturer:
Atmel
Quantity:
10 000
Part Number:
ATmega168A-AU
Manufacturer:
Microchip Technology
Quantity:
12 280
Part Number:
ATmega168A-AUR
Manufacturer:
Atmel
Quantity:
10 000
Part Number:
ATmega168A-AUR
Manufacturer:
Microchip Technology
Quantity:
420
Part Number:
ATmega168A-CCU
Manufacturer:
Atmel
Quantity:
10 000
Part Number:
ATmega168A-CCU
Manufacturer:
Microchip Technology
Quantity:
309
Part Number:
ATmega168A-CCUR
Manufacturer:
Atmel
Quantity:
10 000
Part Number:
ATmega168A-CCUR
Manufacturer:
Microchip Technology
Quantity:
469
Part Number:
ATmega168A-MMH
Manufacturer:
Microchip Technology
Quantity:
2 027
Part Number:
ATmega168A-PU
Manufacturer:
ATMEL
Quantity:
1 000
Company:
Part Number:
ATmega168A-PU
Manufacturer:
ATMEL
Quantity:
4 800
24.5
8271D–AVR–05/11
Changing Channel or Reference Selection
Figure 24-7. ADC Timing Diagram, Free Running Conversion
Table 24-1.
The MUXn and REFS1:0 bits in the ADMUX Register are single buffered through a temporary
register to which the CPU has random access. This ensures that the channels and reference
selection only takes place at a safe point during the conversion. The channel and reference
selection is continuously updated until a conversion is started. Once the conversion starts, the
channel and reference selection is locked to ensure a sufficient sampling time for the ADC. Con-
tinuous updating resumes in the last ADC clock cycle before the conversion completes (ADIF in
ADCSRA is set). Note that the conversion starts on the following rising ADC clock edge after
ADSC is written. The user is thus advised not to write new channel or reference selection values
to ADMUX until one ADC clock cycle after ADSC is written.
If Auto Triggering is used, the exact time of the triggering event can be indeterministic. Special
care must be taken when updating the ADMUX Register, in order to control which conversion
will be affected by the new settings.
If both ADATE and ADEN is written to one, an interrupt event can occur at any time. If the
ADMUX Register is changed in this period, the user cannot tell if the next conversion is based
on the old or the new settings. ADMUX can be safely updated in the following ways:
When updating ADMUX in one of these conditions, the new settings will affect the next ADC
conversion.
Condition
First conversion
Normal conversions, single ended
Auto Triggered conversions
a. When ADATE or ADEN is cleared.
b. During conversion, minimum one ADC clock cycle after the trigger event.
c. After a conversion, before the Interrupt Flag used as trigger source is cleared.
ADC Conversion Time
ATmega48A/PA/88A/PA/168A/PA/328/P
Cycle Number
ADC Clock
ADSC
ADIF
ADCH
ADCL
Conversion
Complete
One Conversion
11
Sample & Hold
(Cycles from Start of Conversion)
12
13
Next Conversion
1
13.5
Sign and MSB of Result
LSB of Result
1.5
2
2
MUX and REFS
Update
3
Sample & Hold
4
Conversion Time
(Cycles)
13.5
25
13
257

Related parts for ATmega168A