how to generate this clock waveform with PLL

[taofeng]

Hi,
I want to generate N clock cycles with T+ deltaT , then N clock cycles with T+2*deltaT, then N clock cycles with T+3*deltaT,..... and then go back, N cycles with T-deltaT, T-2*deltaT , T-3*deltaT. Please see the attached for details.

thanks,


jef

 

[AdvaRes]

Hi,
I want to generate N clock cycles with T+ deltaT , then N clock cycles with T+2*deltaT, then N clock cycles with T+3*deltaT,..... and then go back, N cycles with T-deltaT, T-2*deltaT , T-3*deltaT. Please see the attached for details.

thanks,


jef

Hi taofeng,
is T+deltaT a voltage, a current or what ?

 

[FvM]

Cause the waveform has 5 discrete levels, it involves at least a 3 bit output signal. It can be easily generated by a 3 bit counter and digital logic. You also need some kind of a 3-Bit-DAC, e.g. a resistor network or weighted current sources.

 

[AdvaRes]

Cause the waveform has 5 discrete levels, it involves at least a 3 bit output signal. It can be easily generated by a 3 bit counter and digital logic. You also need some kind of a 3-Bit-DAC, e.g. a resistor network or weighted current sources.

@taofeng
Are you designing a DPLL ?

Nice idea FvM.
I would think to use a N (or N/2) counter ,a 3 bit counter an appropriate encoder for the retur and a DAC.

 

[taofeng]

Hi,
I want to generate N clock cycles with T+ deltaT , then N clock cycles with T+2*deltaT, then N clock cycles with T+3*deltaT,..... and then go back, N cycles with T-deltaT, T-2*deltaT , T-3*deltaT. Please see the attached for details.

thanks,


jef

Hi taofeng,
is T+deltaT a voltage, a current or what ?

It is clock period !

Added after 1 minutes:

Cause the waveform has 5 discrete levels, it involves at least a 3 bit output signal. It can be easily generated by a 3 bit counter and digital logic. You also need some kind of a 3-Bit-DAC, e.g. a resistor network or weighted current sources.

@taofeng
Are you designing a DPLL ?

Nice idea FvM.
I would think to use a N (or N/2) counter ,a 3 bit counter an appropriate encoder for the retur and a DAC.

thank you for the reply, but I want to different clock frequencies, not the voltage ! thanks

 

[erikl]

I want different clock frequencies, not the voltage ! thanks

Then I guess this would be a nice job for a µP.