The maximum clock frequency of the SN74HC166NSR is 30 MHz, but it can vary depending on the operating voltage and load capacitance. It's recommended to check the timing characteristics in the datasheet for specific frequency limits.
To ensure proper power and decoupling, connect the VCC pin to a stable 2-6V power supply, and decouple the power supply lines with 0.1uF ceramic capacitors as close to the device as possible. Additionally, use a 10uF bulk capacitor to filter out noise and ripple.
The maximum input voltage that the SN74HC166NSR can tolerate is 7V, but it's recommended to keep the input voltage within the recommended operating range of 2-6V to ensure reliable operation.
The asynchronous clear (CLR) input should be tied to VCC through a pull-up resistor (e.g., 1kΩ) to prevent unwanted clearing of the shift register. When CLR is low, the shift register is cleared, and when CLR is high, the shift register operates normally.
The recommended method for serial data input is to use a single-ended input with a pull-up resistor (e.g., 1kΩ) to VCC. This ensures that the input is properly terminated and reduces noise susceptibility.
SN74HC166NSR datasheet
by Texas Instruments
