M74HC688B1R datasheet by STMicroelectronics

M74HC688B1R Frequently Asked Questions (FAQs)

• What is the maximum clock frequency for the M74HC688B1R?
  The maximum clock frequency for the M74HC688B1R is 30 MHz, but it can operate up to 40 MHz with a reduced voltage supply (VCC) of 4.5V.
• How do I handle the asynchronous reset (RST) input?
  The asynchronous reset (RST) input should be asserted low (GND) for at least 2 clock cycles to ensure a proper reset. It's recommended to use a pull-up resistor on the RST pin to prevent unwanted resets.
• What is the recommended power-on reset (POR) circuit for the M74HC688B1R?
  A simple POR circuit can be implemented using a resistor, capacitor, and diode. The capacitor should be charged to VCC through the resistor, and the diode should be connected between the capacitor and the RST pin to ensure a clean reset signal.
• How do I interface the M74HC688B1R with a microcontroller?
  The M74HC688B1R can be interfaced with a microcontroller using a standard 8-bit bus interface. The microcontroller should provide the clock signal, and the M74HC688B1R will generate the necessary control signals for the memory devices.
• What is the maximum capacitive load for the M74HC688B1R's output pins?
  The maximum capacitive load for the M74HC688B1R's output pins is 100 pF. Exceeding this limit may affect the device's performance and reliability.