P PL Liew New Member Feb 20, 2014 #1 this is one of my college exercise. the question is A circuit designer converts a 50 kHz, 70 % duty cycle input waveform to a 50 kHz, 50 % duty cycle using IC 74LS221. Determine the pulse-width of the output waveform. and my answer is T = 1/F = 1/50k = 0.02ms Percentage Duty cycle = (TH / T) × 50% = 1ms but the correct answer is 10 micro s. can someone explain to me ? please.... Last edited: Feb 20, 2014
this is one of my college exercise. the question is A circuit designer converts a 50 kHz, 70 % duty cycle input waveform to a 50 kHz, 50 % duty cycle using IC 74LS221. Determine the pulse-width of the output waveform. and my answer is T = 1/F = 1/50k = 0.02ms Percentage Duty cycle = (TH / T) × 50% = 1ms but the correct answer is 10 micro s. can someone explain to me ? please....
JimB Super Moderator Most Helpful Member Feb 20, 2014 #2 can someone explain to me ? please Click to expand... Yes, careless arithmetic. T = 1/F = 1/50k = 0.02ms Click to expand... Correct. Percentage Duty cycle = (TH / T) × 50% = 1ms Click to expand... Wrong but the correct answer is 10 micro s Click to expand... Quite right. JimB
can someone explain to me ? please Click to expand... Yes, careless arithmetic. T = 1/F = 1/50k = 0.02ms Click to expand... Correct. Percentage Duty cycle = (TH / T) × 50% = 1ms Click to expand... Wrong but the correct answer is 10 micro s Click to expand... Quite right. JimB
P PL Liew New Member Feb 20, 2014 #3 then how u calculate ? the 74LS221 is non retriggerable one shot
P PL Liew New Member Feb 20, 2014 #4 here's my solution. period (T) = 1 / F = 1 / 50 kHz = 0.02 ms since duty cycle is 50 % 0.5 * (PW / T ) = 0.5 * (PW / 0.02 ms) hence, the pulse width (PW) is 10 micro seconds
here's my solution. period (T) = 1 / F = 1 / 50 kHz = 0.02 ms since duty cycle is 50 % 0.5 * (PW / T ) = 0.5 * (PW / 0.02 ms) hence, the pulse width (PW) is 10 micro seconds