I'm using the CD4541B as a digital timer and have selected Rtc and Ctc for a 21 second count with pins 12 and 13 tied high. I do NOT want the powering on of the device to change the output state. I only want the output to change state when triggered by the MASTER RESET pin.
Here are my relevant inputs:
Pin 5 (AUTO RESET) - tied high
Pin 6 (MASTER RESET) - trigger input, kept low for the time being
Pin 9 (Q, /Q SELECT) - tied low
Pin 10 (MODE) - tied low
Pin 12 (A) - tied high
Pin 13 (B) - tied high
I've tied the AUTO RESET high so, according to the data sheet, this should disable the auto reset circuit. However, the output changes state after 21 seconds even though pin 5 is kept high and pin 6 is kept low. Is this normal behavior from the CD4541B?
How can I truly disable the power on reset functionality of this device? If it's not possible, can someone recommend another device to act as a simple timer?
Thanks.
