Joined Sep 3, 2014
I have a question regarding one of the 4538 monostable ic's pin connection. I have read two datasheets for the 4538 (included in links below) and both of them states, that pin 1 or pin 15 (doesn't matter which, since it's a dual monostable in one package) apart from connecting to the timing capacitor needs to be connected to ground. However, on page 5 of NXP's datasheet there is no connection to ground and in all of the online available circuit designs there is no connection from pin 1 to ground. On the contrary, on page 2 of Fairchild's datasheet, there is a connection going from pin 1 to ground. I have constructed the circuit on a breadboard each way and I found that both one is operational, although when I add ground, timing is not that accurate. My questions are: Is pin 1 internally grounded so there is no need for external grounding and I misunderstood the "always connected to ground" statement? Can it be harmful for the circuit if I include/do not include an external ground on pin 1?
Thank you for the answers in advance!