74HC191D,652 datasheet by NXP Semiconductors

74HC191D,652 Frequently Asked Questions (FAQs)

• What is the maximum clock frequency that can be used with the 74HC191D,652?
  The maximum clock frequency for the 74HC191D,652 is 25 MHz, but it can be affected by factors such as supply voltage, temperature, and capacitive loading. It's recommended to check the timing diagrams and specifications in the datasheet to ensure proper operation.
• How do I ensure that the 74HC191D,652 is properly reset during power-up?
  To ensure proper reset, connect the MR (Master Reset) input to a pull-up resistor and a capacitor to VCC. This will ensure that the device is reset during power-up and that the counters are initialized to zero.
• Can I use the 74HC191D,652 as a binary counter or only as a BCD counter?
  The 74HC191D,652 can be used as both a binary counter and a BCD (Binary-Coded Decimal) counter. The device has a mode input (MOD) that allows you to select between binary and BCD counting modes.
• What is the maximum count value that can be achieved with the 74HC191D,652?
  The 74HC191D,652 is a 4-bit synchronous counter, which means it can count up to 2^4 - 1 = 15 in binary mode or 0-9 in BCD mode. If you need to count higher, you can cascade multiple devices or use a different counter IC.
• How do I handle the carry-out (CO) signal in my design?
  The carry-out (CO) signal is used to cascade multiple counters or to trigger other logic circuits. You can connect the CO signal to the clock input of another counter or to a logic gate to perform further processing. Make sure to check the timing diagrams and specifications in the datasheet to ensure proper operation.