SN74HC166DBR datasheet by Texas Instruments

SN74HC166DBR Frequently Asked Questions (FAQs)

• What is the maximum clock frequency that the SN74HC166DBR can handle?
  The maximum clock frequency of the SN74HC166DBR 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.
• How do I ensure that the SN74HC166DBR is properly powered and decoupled?
  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.
• What is the maximum current that the SN74HC166DBR can sink or source?
  The SN74HC166DBR can sink or source up to 25mA of current per output pin, but it's recommended to limit the current to 10mA or less to ensure reliable operation and prevent overheating.
• How do I handle the asynchronous clear (CLR) input?
  The asynchronous clear (CLR) input should be tied to VCC through a pull-up resistor (e.g., 1kΩ) to prevent accidental clearing of the shift register. When CLR is low, the shift register is cleared, and the outputs are set to low.
• What is the recommended method for serially loading data into the SN74HC166DBR?
  To serially load data into the SN74HC166DBR, connect the serial data input (DS) to the output of a previous stage or a microcontroller. Apply the clock signal (CLK) to the clock input, and ensure that the shift register is cleared before loading data. Use the serial output (QH) to cascade multiple devices.