CD74HC191E datasheet by Texas Instruments

CD74HC191E Frequently Asked Questions (FAQs)

• What is the maximum clock frequency that the CD74HC191E can handle?
  The CD74HC191E can handle clock frequencies up to 25 MHz, but it's recommended to check the specific application and operating conditions to ensure reliable operation.
• How do I ensure that the CD74HC191E is properly reset during power-up?
  To ensure proper reset, connect the MR (Master Reset) pin to a pull-up resistor and a capacitor to VCC, and make sure the reset pulse is at least 10 ns wide.
• What is the recommended operating voltage range for the CD74HC191E?
  The recommended operating voltage range for the CD74HC191E is 2 V to 6 V, with a typical operating voltage of 5 V.
• Can I use the CD74HC191E in a 3.3 V system?
  Yes, the CD74HC191E can operate at 3.3 V, but the output voltage levels may not be compatible with 3.3 V logic. Ensure that the output voltage levels meet the requirements of the receiving device.
• How do I handle the asynchronous clear input (CLR) during power-up?
  To avoid unintended clearing of the counter, connect the CLR pin to VCC through a pull-up resistor or a logic gate that ensures the CLR pin is high during power-up.