AT90USB647-MU Atmel, AT90USB647-MU Datasheet - Page 60

• Manufacturer Part Number: AT90USB647-MU
• Description: MCU, 8BIT, 64K FLASH, USB, 64QFN
• Manufacturer: Atmel

Specifications of AT90USB647-MU

• Controller Family/series: AT90
• No. Of I/o's: 48
• Eeprom Memory Size: 2KB
• Ram Memory Size: 4KB
• Cpu Speed: 16MHz
• No. Of: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 64KB
• Oscillator Type: External, Internal
• Package: 64QFN EP
• Device Core: AVR
• Family Name: AT90
• Maximum Speed: 20 MHz
• Ram Size: 4 KB
• Operating Supply Voltage: 3.3|5 V
• Data Bus Width: 8 Bit
• Program Memory Type: Flash
• Number Of Programmable I/os: 48
• Interface Type: SPI/TWI/USART/USB
• On-chip Adc: 8-chx10-bit
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 4
• Lead Free Status / Rohs Status: Details

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
=