ATMEGA168-20PU Atmel, ATMEGA168-20PU Datasheet - Page 347

• Manufacturer Part Number: ATMEGA168-20PU
• Description: IC AVR MCU 16K 20MHZ 28DIP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA168-20PU

• 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: 16KB (8K 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 6x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-DIP (0.300", 7.62mm)
• Processor Series: ATMEGA16x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 1 KB
• Interface Type: 2-Wire, SPI, USART, Serial
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 23
• Number Of Timers: 3
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 6 Channel
• A/d Inputs: 6-Channel, 10-Bit
• Cpu Speed: 20 MIPS
• Eeprom Memory: 512 Bytes
• Input Output: 23
• Interface: I2C/SPI/UART/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 28-pin PDIP
• Programmable Memory: 16K Bytes
• Timers: 2-8-bit, 1-16-bit
• Voltage, Range: 4.5-5.5 V
• Controller Family/series: AVR MEGA
• No. Of I/o's: 23
• Eeprom Memory Size: 512Byte
• Ram Memory Size: 1KB
• Rohs Compliant: Yes
• For Use With: ATSTK600-TQFP32 - STK600 SOCKET/ADAPTER 32-TQFPATSTK600 - DEV KIT FOR AVR/AVR32770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATAVRISP2 - PROGRAMMER AVR IN SYSTEMATJTAGICE2 - AVR ON-CHIP D-BUG SYSTEM
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

32. Errata
32.1
32.1.1
2545E–AVR–02/05
Errata ATmega48
Rev A
The revision letter in this section refers to the revision of the ATmega48 device.
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1. Wrong values read after Erase Only operation
At supply voltages below 2.7 V, an EEPROM location that is erased by the Erase Only operation
may read as programmed (0x00).
If it is necessary to read an EEPROM location after Erase Only, use an Atomic Write operation
with 0xFF as data in order to erase a location. In any case, the Write Only operation can be used
as intended. Thus no special considerations are needed as long as the erased location is not
read before it is programmed.
2. Watchdog Timer Interrupt disabled
If the watchdog timer interrupt flag is not cleared before a new timeout occurs, the watchdog will
be disabled, and the interrupt flag will automatically be cleared. This is only applicable in inter-
rupt only mode. If the Watchdog is configured to reset the device in the watchdog time-out
following an interrupt, the device works correctly.
Make sure there is enough time to always service the first timeout event before a new watchdog
timeout occurs. This is done by selecting a long enough time-out period.
3. Start-up time with Crystal Oscillator is higher than expected
The clock counting part of the start-up time is about 2 times higher than expected for all start-up
periods when running on an external Crystal. This applies only when waking up by reset. Wake-
up from power down is not affected. For most settings, the clock counting parts is a small frac-
tion of the overall start-up time, and thus, the problem can be ignored. The exception is when
using a very low frequency crystal like for instance a 32 kHz clock crystal.
No known workaround.
4. High Power Consumption in Power-down with External Clock
The power consumption in power down with an active external clock is about 10 times higher
than when using internal RC or external oscillators.
Stop the external clock when the device is in power down.
5. Asynchronous Oscillator does not stop in Power-down
Wrong values read after Erase Only operation
Watchdog Timer Interrupt disabled
Start-up time with Crystal Oscillator is higher than expected
High Power Consumption in Power-down with External Clock
Asynchronous Oscillator does not stop in Power-down
Problem Fix/Workaround
Problem fix / Workaround
Problem fix / Workaround
Problem fix / Workaround
ATmega48/88/168
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