ATMEGA32A-AN Atmel, ATMEGA32A-AN Datasheet - Page 31

• Manufacturer Part Number: ATMEGA32A-AN
• Description: IC MCU AVR 32K FLASH 44TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA32A-AN

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• 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: 44-TQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.9
8155C–AVR–02/11
Timer/Counter Oscillator
Figure 8-4.
When this clock source is selected, start-up times are determined by the SUT fuses as shown in
Table
Table 8-10.
When applying an external clock, it is required to avoid sudden changes in the applied clock fre-
quency to ensure stable operation of the MCU. A variation in frequency of more than 2% from
one clock cycle to the next can lead to unpredictable behavior. It is required to ensure that the
MCU is kept in reset during such changes in the clock frequency.
For AVR microcontrollers with Timer/Counter Oscillator pins (TOSC1 and TOSC2), the crystal is
connected directly between the pins. No external capacitors are needed. The Oscillator is opti-
mized for use with a 32.768kHz watch crystal. Applying an external clock source to TOSC1 is
not recommended.
Note:
SUT1:0
00
01
10
11
8-10.
The Timer/Counter Oscillator uses the same type of crystal oscillator as Low-Frequency Oscillator
and the internal capacitors have the same nominal value of 36pF.
External Clock Drive Configuration
Start-up Times for the External Clock Selection
Start-up Time from
Power-down and
Power-save
6 CK
6 CK
6 CK
EXTERNAL
SIGNAL
CLOCK
Additional Delay
(V
from Reset
CC
Reserved
4.1ms
65ms
= 5.0V)
–
Recommended Usage
BOD enabled
Fast rising power
Slowly rising power
ATmega32A
31