Datasheet

257
ATmega16U4/32U4 [DATASHEET]
Atmel-7766J-USB-ATmega16U4/32U4-Datasheet_04/2016
21.3 Typical Application Implementation
Depending on the target application power supply, the ATmega16U4/ATmega32U4 requires different hardware
typical implementations.
Figure 21-2. Operating Modes versus Frequency and Power-supply
21.3.1 Bus Powered Device
Figure 21-3. Typical Bus Powered Application with 5V I/O
VCC (V)
VCC min
0
3.0
3.4
5.5
USB not operational
USB compliant,
without internal regulator
USB compliant,
with internal regulator
4.5
2.7
Max
Operating Frequency (MHz)
8 MHz
16 MHz
2 MHz
3.6
1µF
UDP
UDM
VBUS
UVSS
UID
UCAP
D-
D+
VBUS
UID
UGND
UVCC AVCC VCC
XTAL1 XTAL2 GND GND
Rs=22
Rs=22