The Question: If you use the 74LS123 with an external resistance of 10 k but do not use an external capacitor, what do you get for the pulse width?
The Solution Attempt: So first I took a look at the data sheet (http://www.futurlec.com/74LS/74LS123.shtml) which presents some confusing information. Operating Rule 1 says an external resistor and external capacitor are required for proper operation. But then the same rule goes on to state that the external capacitor's capacitance may range from 0 to any necessary value. That sounds to me then like an external capacitor isn't required. So I look for a formula or chart for the pulse width but all that's provided is a formula for when (external capacitance) >> 1000 pF and a graph for when 10 pF < (external capacitance) < 1000 pF, so I'm not sure how to find the pulse width for (external capacitance) = 0. How might I proceed?
The Solution Attempt: So first I took a look at the data sheet (http://www.futurlec.com/74LS/74LS123.shtml) which presents some confusing information. Operating Rule 1 says an external resistor and external capacitor are required for proper operation. But then the same rule goes on to state that the external capacitor's capacitance may range from 0 to any necessary value. That sounds to me then like an external capacitor isn't required. So I look for a formula or chart for the pulse width but all that's provided is a formula for when (external capacitance) >> 1000 pF and a graph for when 10 pF < (external capacitance) < 1000 pF, so I'm not sure how to find the pulse width for (external capacitance) = 0. How might I proceed?