ATmega32U4 Atmel Corporation, ATmega32U4 Datasheet - Page 297

• Manufacturer Part Number: ATmega32U4
• Manufacturer: Atmel Corporation

Specifications of ATmega32U4

• Flash (kbytes): 32 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 14
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 26
• Ext Interrupts: 13
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 12
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 3.3
• Eeprom (bytes): 1024
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 4
• Output Compare Channels: 12
• Input Capture Channels: 2
• Pwm Channels: 8
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

24.4.1
7766F–AVR–11/10
Differential Channels
Figure 24-6. ADC Timing Diagram, Auto Triggered Conversion
Figure 24-7. ADC Timing Diagram, Free Running Conversion
Table 24-1.
When using differential channels, certain aspects of the conversion need to be taken into
consideration.
Differential conversions are synchronized to the internal clock CK
clock frequency. This synchronization is done automatically by the ADC interface in such a way
that the sample-and-hold occurs at a specific phase of CK
user (i.e., all single conversions, and the first free running conversion) when CK
take the same amount of time as a single ended conversion (13 ADC clock cycles from the next
prescaled clock cycle). A conversion initiated by the user when CK
Condition
Sample & Hold
(Cycles from Start of Convention)
Conversion Time
(Cycles)
Cycle Number
ADC Clock
Trigger
Source
ADATE
ADIF
ADCH
ADCL
ADC Conversion Time
Prescaler
Reset
MUX and REFS
Update
1
2
3
Sample &
Hold
4
Conversion
5
First
14.5
25
6
7
One Conversion
8
Cycle Number
ADC Clock
ADSC
ADIF
ADCH
ADCL
9
Conversion
Single Ended
10
Conversion
Complete
Conversion,
Complete
One Conversion
Normal
11
11
1.5
13
12
ADC2
12
13
13
ATmega16/32U4
. A conversion initiated by the
ADC2
Next Conversion
1
Sign and MSB of Result
Sign and MSB of Result
LSB of Result
ADC2
LSB of Result
2
Auto Triggered
MUX and REFS
Update
is high will take 14 ADC
Next Conversion
Convertion
equal to half the ADC
1
Prescaler
Reset
3
13.5
Sample & Hold
2
2
4
ADC2
is low will
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