The maximum frequency of operation for the HEF4069UBT is 10 MHz.
To ensure proper power supply, connect VCC to a stable 5V power source, and connect VSS to GND. Also, decouple the power supply with a 100nF capacitor.
The maximum current that the HEF4069UBT can sink or source is 20mA per output pin.
Unused inputs should be connected to VCC or GND through a 1kΩ resistor to prevent floating inputs and reduce power consumption.
The HEF4069UBT is rated for operation up to 125°C, but it's recommended to derate the device for reliable operation above 85°C.
HEF4069UBT,652 datasheet
by NXP Semiconductors
