35.2.8 Pin Driver Strength Figure 35-69. ATmega168PB: I/O Pin Output Voltage vs. Sink Current (VCC = 3V) Figure 35-70. ATmega168PB: I/O Pin Output Voltage vs. Sink Current (VCC = 5V) Figure 35-71. ATmega168PB: I/O Pin Output Voltage vs. Source Current (VCC = 3V) Figure 35-72. ATmega168PB I/O Pin Output Voltage vs. Source Current (VCC = 5V)