ATMEGA32U4-16AU ATMEL [ATMEL Corporation], ATMEGA32U4-16AU Datasheet - Page 21

• Manufacturer Part Number: ATMEGA32U4-16AU
• Description: 8-bit Microcontroller with 16/32K Bytes of ISP Flash and USB Controller
• Manufacturer: ATMEL [ATMEL Corporation]

8. Errata
8.1
7766BS–AVR–07/08
ATmega16U4/ATmega32U4 Rev A
The revision letter in this section refers to the revision of the ATmega16U4/ATmega32U4
device.
1. Spike on TWI pins when TWI is enabled
2. High current consumption in sleep mode
3. Extra power comsumption
4. Internal RC oscillator start up issue.
5. Internal RC oscillator calibration issue.
100 ns negative spike occurs on SDA and SCL pins when TWI is enabled.
Problem Fix/work around
No known work around, enable ATmega16U4/ATmega32U4 TWI first versus the others
nodes of the TWI network.
If a pending interrupt cannot wake the part up from the selected mode, the current consump-
tion will increase during sleep when executing the SLEEP instruction directly after a SEI
instruction.
Problem Fix/work around
Before entering sleep, interrupts not used to wake up the part from the sleep mode should
be disabled.
The typical power comsumption is increased by about 30µA in power-down mode.
Problem Fix/work around
None.
When the part is configured to start on internal RC, the oscillator may not start properly after
power-on.
Problem Fix/work around
Do not configure the part to start with the internal oscillator (default part configuration is to
start with the external crystal oscillator).
The default internal RC oscillator frequency may be lower that 8MHz.
Problem Fix/work around
Parts are configured so that the internal RC oscillator frequency is as close as possible to
the 8MHz default target frequency.
ATmega16U4/ATmega32U4
21