AT89LP51ED2-20AAU Atmel, AT89LP51ED2-20AAU Datasheet - Page 54

• Manufacturer Part Number: AT89LP51ED2-20AAU
• Description: 8-bit Microcontrollers - MCU 64KB 20MHz 2.4V-5.5V
• Manufacturer: Atmel

Specifications of AT89LP51ED2-20AAU

• Rohs: yes
• Core: 8051
• Processor Series: AT89x
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 20 MHz
• Program Memory Size: 64 KB
• Data Ram Size: 256 B
• On-chip Adc: Yes
• Operating Supply Voltage: 2.4 V to 5.5 V
• Operating Temperature Range: - 40 C to + 85 C
• Package / Case: LQFP-44
• Mounting Style: SMD/SMT
• Data Rom Size: 4 KB
• Interface Type: 2-Wire, SPI, UART
• Number Of Programmable I/os: 36
• Number Of Timers: 3
• Program Memory Type: Flash
• Factory Pack Quantity: 160

7.2
54
Brown-out Reset
AT89LP51RD2/ED2/ID2 Preliminary
Figure 7-2.
Note:
Table 7-1.
The AT89LP51RD2/ED2/ID2 has an on-chip Brown-out Detection (BOD) circuit for monitoring
the V
the BOD is nominally 2.0V. The purpose of the BOD is to ensure that if V
executing at speed, the system will gracefully enter reset without the possibility of errors induced
by incorrect execution. A BOD sequence is shown in
below the trigger level V
above the trigger level plus about 200 mV of hysteresis, the start-up timer releases the internal
reset after the specified time-out period has expired
The BOD does not generate a reset output pulse except as part of a POR event.
SUT Fuse 1
DD
0
0
1
1
t
level during operation by comparing it to a fixed trigger level. The trigger level V
POR
Time-out
Internal
Internal
is approximately 143 µs ± 5%.
Reset
Reset
Power-on Reset Sequence
Start-up Timer Settings
POL
RST
RST
V
DD
SUT Fuse 0
t
POR
V
0
1
0
1
BOD
POR
, the internal reset is immediately activated. When V
V
BOD
Clock Source
Internal RC/External Clock
Crystal Oscillator
Internal RC/External Clock
Crystal Oscillator
Internal RC/External Clock
Crystal Oscillator
Internal RC/External Clock
Crystal Oscillator
output
output
t
SUT
(Table
Figure
(POL Tied to VCC)
input
V
7-1).
7-3. When V
IL
(RST left unconnected)
V
IL
DD
(RST extended
DD
externally)
decreases to a value
t
RHD
fails or dips while
t
SUT
3714A–MICRO–7/11
16384
(± 5%) µs
1024
2048
1024
4096
4096
DD
512
16
increases
BOD
for