ATMEGA88-20MUR Atmel, ATMEGA88-20MUR Datasheet - Page 47

• Manufacturer Part Number: ATMEGA88-20MUR
• Description: MCU AVR 8K FLASH 20MHZ 32QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA88-20MUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 23
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K 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: *
• Cpu Family: ATmega
• Device Core: AVR
• Device Core Size: 8b
• Frequency (max): 20MHz
• Interface Type: SPI/TWI/USART
• Total Internal Ram Size: 1KB
• # I/os (max): 23
• Number Of Timers - General Purpose: 3
• Operating Supply Voltage (typ): 3.3/5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 2.7V
• On-chip Adc: 8-chx10-bit
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 32
• Package Type: MLF EP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

11.4
11.5
2545T–AVR–05/11
External reset
Brown-out detection
Figure 11-3. MCU start-up, RESET extended externally.
An external reset is generated by a low level on the RESET pin. Reset pulses longer than the
minimum pulse width (see
even if the clock is not running. Shorter pulses are not guaranteed to generate a reset. When the
applied signal reaches the reset threshold voltage – V
ter starts the MCU after the time-out period – t
disabled by the RSTDISBL fuse, see
Figure 11-4. External reset during operation.
The Atmel ATmega48/88/168 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
decreases to a value below the trigger level (V
reset is immediately activated. When V
on page
The BOD circuit will only detect a drop in V
ger than t
BOT+
INTERNAL
TIME-OUT
CC
= V
RESET
RESET
level during operation by comparing it to a fixed trigger level. The trigger level for the
48), the delay counter starts the MCU after the Time-out period t
BOD
V
BOT
CC
CC
given in
+ V
HYST
“System and reset characteristics” on page
/2 and V
“System and reset characteristics” on page
V
POT
BOT-
Table 28-6 on page
= V
CC
BOT
increases above the trigger level (V
CC
- V
if the voltage stays below the trigger level for lon-
V
BOT-
RST
TOUT
HYST
t
TOUT
in
– has expired. The external reset can be
RST
/2.When the BOD is enabled, and V
Figure 11-5 on page
287.
– on its positive edge, the delay coun-
ATmega48/88/168
307.
307) will generate a reset,
TOUT
48), the brown-out
BOT+
has expired.
in
Figure 11-5
47
CC