ATmega3250A Atmel Corporation, ATmega3250A Datasheet - Page 248

• Manufacturer Part Number: ATmega3250A
• Manufacturer: Atmel Corporation

Specifications of ATmega3250A

• Flash (kbytes): 32 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 69
• Ext Interrupts: 25
• 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: No
• Crypto Engine: No
• Sram (kbytes): 2
• 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: 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

25.5.5
Table 25-3.
8285D–AVR–06/11
Signal Name
COMP
ACLK
ACTEN
ADCBGEN
ADCEN
AMPEN
Scanning the ADC
Boundary-scan Signals for the ADC
Direction as seen
from the ADC
Output
Input
Input
Input
Input
Input
ATmega165A/PA/325A/PA/3250A/PA/645A/P/6450A/P
Figure 25-9 on page 248
observe signals. The Boundary-scan cell from
these signals. The ADC need not be used for pure connectivity testing, since all analog inputs
are shared with a digital port pin as well.
Figure 25-9. Analog to Digital Converter
The signals are described briefly in
NEGSEL_2
NEGSEL_1
NEGSEL_0
MUXEN_7
MUXEN_6
MUXEN_5
MUXEN_4
MUXEN_3
MUXEN_2
MUXEN_1
MUXEN_0
EXTCH
ADC_7
ADC_6
ADC_5
ADC_4
ADC_3
ADC_2
ADC_1
ADC_0
Description
Comparator Output
Clock signal to differential amplifier
implemented as Switch-cap filters
Enable path from differential
amplifier to the comparator
Enable Band-gap reference as
negative input to comparator
Power-on signal to the ADC
Power-on signal to the differential
amplifier
ADC_2
ADC_0
ADC_1
SCTEST
AMPEN
ACLK
(1)
ST
To Comparator
shows a block diagram of the ADC with all relevant control and
+
-
1x
Table 25-3 on page
ADCBGEN
VCCREN
IREFEN
AREF
PASSEN
Recommended
Input when not
in Use
ACTEN
1.22V
GNDEN
ref
Figure 25-5 on page 245
1.11V
ref
0
0
0
0
0
0
248.
PRECH
DAC_9..0
ADCEN
HOLD
Output Values when
recommended inputs are Used,
and CPU is not Using the ADC
PRECH
AREF
10-bit DAC
is attached to each of
AREF
0
0
0
0
0
0
+
-
DACOUT
COMP
COMP
248