AT90USB646-AUR Atmel, AT90USB646-AUR Datasheet - Page 60

• Manufacturer Part Number: AT90USB646-AUR
• Description: MCU AVR 64K FLASH 16MHZ 64TQFP
• Manufacturer: Atmel
• Series: AVR® 90USBr

Specifications of AT90USB646-AUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART, USB, USB OTG
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 48
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K 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
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Interface Type: SPI, UART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 48
• Number Of Timers: 4
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.5
60
Brown-out Detection
AT90USB64/128
Figure 8-4.
AT90USB64/128 has an On-chip Brown-out Detection (BOD) circuit for monitoring the V
during operation by comparing it to a fixed trigger level. The trigger level for the 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
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
Symbol
V
t
Ibod
BOT
BOD
BOT+
HYST
+ V
BODLEVEL 2..0 Fuses
in
HYST
BOD
Figure
CC
/2 and V
Parameter
Brown-out Detector Hysteresis
Min Pulse Width on Brown-out Reset
Brown-out Detector Consumption
given in
External Reset During Operation
BODLEVEL Fuse Coding
Brown-out Characteristics
111
110
101
100
011
010
001
000
8-5), the delay counter starts the MCU after the Time-out period t
BOT-
Table
= V
8-1.
BOT
- V
CC
HYST
Min V
decreases to a value below the trigger level (V
2.4
3.2
3.3
4.1
/2..
BOT
CC
if the voltage stays below the trigger level for lon-
Typ V
2.6
3.4
3.5
4.3
BOD Disabled
Reserved
BOT
Min
CC
increases above the trigger level
Typ
50
25
Max V
2.8
3.6
3.7
4.5
BOT
Max
V
Units
Units
mV
µA
ns
7593K–AVR–11/09
BOT-
TOUT
in
CC
BOT+
Figure
level
has
=