ATmega168A Atmel Corporation, ATmega168A Datasheet - Page 255

ATmega168A
Manufacturer Part Number
ATmega168A
Description
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
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
ATmega168A-AU
Manufacturer:
ATMEL
Quantity:
464
Part Number:
ATmega168A-AU
Manufacturer:
ATMEL/爱特梅尔
Quantity:
20 000
Part Number:
ATmega168A-MU
Manufacturer:
ATMEL/爱特梅尔
Quantity:
20 000
Company:
Part Number:
ATmega168A-PU
Manufacturer:
ATMEL
Quantity:
1 000
- Current page: 255 of 567
- Download datasheet (21Mb)
24.4
8271D–AVR–05/11
Prescaling and Conversion Timing
If Auto Triggering is enabled, single conversions can be started by writing ADSC in ADCSRA to
one. ADSC can also be used to determine if a conversion is in progress. The ADSC bit will be
read as one during a conversion, independently of how the conversion was started.
Figure 24-3. ADC Prescaler
By default, the successive approximation circuitry requires an input clock frequency between
50kHz and 200kHz to get maximum resolution. If a lower resolution than 10 bits is needed, the
input clock frequency to the ADC can be higher than 200kHz to get a higher sample rate.
The ADC module contains a prescaler, which generates an acceptable ADC clock frequency
from any CPU frequency above 100kHz. The prescaling is set by the ADPS bits in ADCSRA.
The prescaler starts counting from the moment the ADC is switched on by setting the ADEN bit
in ADCSRA. The prescaler keeps running for as long as the ADEN bit is set, and is continuously
reset when ADEN is low.
When initiating a single ended conversion by setting the ADSC bit in ADCSRA, the conversion
starts at the following rising edge of the ADC clock cycle.
A normal conversion takes 13 ADC clock cycles. The first conversion after the ADC is switched
on (ADEN in ADCSRA is set) takes 25 ADC clock cycles in order to initialize the analog circuitry.
When the bandgap reference voltage is used as input to the ADC, it will take a certain time for
the voltage to stabilize. If not stabilized, the first value read after the first conversion may be
wrong.
The actual sample-and-hold takes place 1.5 ADC clock cycles after the start of a normal conver-
sion and 13.5 ADC clock cycles after the start of an first conversion. When a conversion is
complete, the result is written to the ADC Data Registers, and ADIF is set. In Single Conversion
mode, ADSC is cleared simultaneously. The software may then set ADSC again, and a new
conversion will be initiated on the first rising ADC clock edge.
When Auto Triggering is used, the prescaler is reset when the trigger event occurs. This assures
a fixed delay from the trigger event to the start of conversion. In this mode, the sample-and-hold
takes place two ADC clock cycles after the rising edge on the trigger source signal. Three addi-
tional CPU clock cycles are used for synchronization logic.
ATmega48A/PA/88A/PA/168A/PA/328/P
ADEN
START
ADPS0
ADPS1
ADPS2
CK
Reset
7-BIT ADC PRESCALER
ADC CLOCK SOURCE
255
Related parts for ATmega168A
Image
Part Number
Description
Manufacturer
Datasheet
Request
R

Part Number:
Description:
INTERVAL AND WIPE/WASH WIPER CONTROL IC WITH DELAY
Manufacturer:
ATMEL Corporation
Datasheet:

Part Number:
Description:
Low-Voltage Voice-Switched IC for Hands-Free Operation
Manufacturer:
ATMEL Corporation
Datasheet:

Part Number:
Description:
MONOLITHIC INTEGRATED FEATUREPHONE CIRCUIT
Manufacturer:
ATMEL Corporation
Datasheet:

Part Number:
Description:
AM-FM Receiver IC U4255BM-M
Manufacturer:
ATMEL Corporation
Datasheet:

Part Number:
Description:
Monolithic Integrated Feature Phone Circuit
Manufacturer:
ATMEL Corporation
Datasheet:

Part Number:
Description:
Multistandard Video-IF and Quasi Parallel Sound Processing
Manufacturer:
ATMEL Corporation
Datasheet:

Part Number:
Description:
High-performance EE PLD
Manufacturer:
ATMEL Corporation
Datasheet:

Part Number:
Description:
8-bit Flash Microcontroller
Manufacturer:
ATMEL Corporation
Datasheet:

Part Number:
Description:
2-Wire Serial EEPROM
Manufacturer:
ATMEL Corporation
Datasheet:

Part Number:
Description:
U6046BREAR WINDOW HEATING TIMER / LONG-TERM TIMER
Manufacturer:
ATMEL Corporation
Datasheet: