ATMEGA32U4-AUR Atmel, ATMEGA32U4-AUR Datasheet - Page 52

• Manufacturer Part Number: ATMEGA32U4-AUR
• Description: MCU AVR 16K FLASH 16MHZ 44TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA32U4-AUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 26
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2.5K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.0.5
7766F–AVR–11/10
Brown-out Detection
ATmega16U4/ATmega32U4 has an On-chip Brown-out Detection (BOD) circuit for monitoring
the V
BOD can be selected by the BODLEVEL Fuses. The trigger level has a hysteresis to ensure
spike free Brown-out Detection. The hysteresis on the detection level should be interpreted as
V
Table 8-2.
Table 8-3.
When the BOD is enabled, and V
8-5), the Brown-out Reset is immediately activated. When V
(V
expired.
The BOD circuit will only detect a drop in V
ger than t
Figure 8-5.
Symbol
V
t
BOT+
BOD
BOT+
HYST
CC
= V
BODLEVEL 2..0 Fuses
in
level during operation by comparing it to a fixed trigger level. The trigger level for the
BOD
BOT
Figure
+ V
given in
BODLEVEL Fuse Coding
Brown-out Characteristics
Parameter
Brown-out Detector Hysteresis
Min Pulse Width on Brown-out Reset
Brown-out Reset During Operation
INTERNAL
TIME-OUT
111
110
101
100
011
010
001
000
HYST
8-5), the delay counter starts the MCU after the Time-out period t
RESET
RESET
V
CC
/2 and V
Table
8-1.
BOT-
CC
= V
decreases to a value below the trigger level (V
BOT
V
BOT-
Min V
- V
1.8
2.0
2.2
2.4
3.2
3.3
4.0
CC
HYST
BOT
if the voltage stays below the trigger level for lon-
/2.
Typ V
2.0
2.2
2.4
2.6
3.4
3.5
4.3
BOD Disabled
CC
BOT
V
t
TOUT
Min
BOT+
increases above the trigger level
ATmega16/32U4
Typ
50
Max V
2.2
2.4
2.6
2.8
3.6
3.7
4.5
BOT
Max
BOT-
TOUT
in
Units
Units
mV
Figure
V
ns
has
52