ATMEGA325P-20AU Atmel, ATMEGA325P-20AU Datasheet - Page 217

• Manufacturer Part Number: ATMEGA325P-20AU
• Description: IC MCU AVR 32K FLASH 64-TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA325P-20AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 54
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP, 64-VQFP
• Processor Series: ATMEGA32x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 2 KB
• Interface Type: SPI, UART, USI
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 54
• Number Of Timers: 3
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Package: 64TQFP
• Device Core: AVR
• Family Name: ATmega
• Maximum Speed: 20 MHz
• Operating Supply Voltage: 3.3|5 V
• Data Rom Size: 1 KB
• Height: 1 mm
• Length: 14 mm
• Supply Voltage (max): 5.5 V, 5.8 V
• Supply Voltage (min): 2.4 V, 2.7 V
• Width: 14 mm
• For Use With: ATSTK600-TQFP64 - STK600 SOCKET/ADAPTER 64-TQFP770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAG770-1005 - ISP 4PORT FOR ATMEL AVR MCU JTAG770-1004 - ISP 4PORT FOR ATMEL AVR MCU SPIATAVRISP2 - PROGRAMMER AVR IN SYSTEM
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ATMEGA325P-16AU; ATMEGA325P-16AU

8023F–AVR–07/09
Figure 21-14. Differential Measurement Range
Table 21-2.
ADMUX = 0xFB (ADC3 - ADC2, 1.1V reference, left adjusted result)
Voltage on ADC3 is 300 mV, voltage on ADC2 is 500 mV.
ADCR = 512 * (300 - 500) / 1100 = -93 = 0x3A3.
ADCL will thus read 0xC0, and ADCH will read 0xD8. Writing zero to ADLAR right adjusts the
result: ADCL = 0xA3, ADCH = 0x03.
V
V
V
...
V
V
V
...
V
V
V
ADCn
ADCm
ADCm
ADCm
ADCm
ADCm
ADCm
ADCm
ADCm
+
+
+
-
-
- V
+ V
1
511
511
510
1
- V
/
/
512
REF
512
/
REF
REF
/
/
512
512
512
V
V
REF
V
Correlation Between Input Voltage and Output Codes
REF
V
V
REF
REF
REF
Read Code
0x1FF
0x1FF
0x1FE
...
0x001
0x000
0x3FF
...
0x201
0x200
Output Code
0x3FF
0x1FF
0x000
0x200
0
ATmega325P/3250P
Corresponding Decimal Value
V
-511
-512
511
511
510
REF
...
-1
...
1
0
Differential Input
Voltage (Volts)
217