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Electronics => Beginners => Topic started by: tarunkumartars on November 13, 2019, 01:07:32 pm

Title: Clock frequency divider circuit (divide by 2) using D flip flop
Post by: tarunkumartars on November 13, 2019, 01:07:32 pm

how can we divide the frequency of (5MHz) with 50% duty cycle to half its frequency  using  D flip flops in hardware ?
Thank you

Title: Re: Clock frequency divider circuit (divide by 2) using D flip flop
Post by: MarkF on November 13, 2019, 01:27:22 pm

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You can also use 4-bit counters to divide by other powers of 2 (SN74LS160 and SN74LS190 series).
These do not need to be LS versions.  Could be CMOS if you need higher voltages.

Title: Re: Clock frequency divider circuit (divide by 2) using D flip flop
Post by: tarunkumartars on November 13, 2019, 01:38:49 pm

 what would be output (Q) when there is no clock given ( initial condition when the Flip flop is just on)? And even negative edge trigger work as well right?

Title: Re: Clock frequency divider circuit (divide by 2) using D flip flop
Post by: wraper on November 13, 2019, 01:55:30 pm

Quote

what would be output (Q) when there is no clock given ( initial condition when the Flip flop is just on)?

Unless you make power on delay for CLR, output on power on is undefined.

Quote

And even negative edge trigger work as well right?

It acts on positive edge. How is it supposed to divide anything while working for both edges?

Title: Re: Clock frequency divider circuit (divide by 2) using D flip flop
Post by: wraper on November 13, 2019, 02:01:51 pm

Quote from: MarkF on November 13, 2019, 01:27:22 pm

These do not need to be LS versions.  Could be CMOS if you need higher voltages.

LS series should die already. Even if you use 5V, there is little reason to use LS, not 74HC74. For higher voltages it would be CD4000 series.