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AD9834: Need help in choosing right solution

Question asked by gt-silicon on Jan 29, 2013
Latest reply on Jan 30, 2013 by gt-silicon

Hello,

 

In my application, I need to scan the sinusoidal wave frequency from 1 kHz to 5 MHz. Peak-to-peak amplitude requirement is 100mV. Quality of sinusoid is important in the application. I also need to repeat the frequency scanning process with different DC bias (say 50mV to 4.95 V).

 

1) Is AD9834 the best solution Analog Devices offers ? If yes, does it have option to sweep the DC bias of sinusoid ? [ I understand that I can use one  DAC in parallel, controlled by the processor, and mix its o/p with the AD9834 o/p. But doing so would require additional SPI ]

 

2) How does the sinusoidal o/p of AD9834 look like? As per datasheet VOUTmax, VOUTmin are 600mV and 30mV. Does it mean that peak-to-peak amplitude and dc bias would be 570mV and 315mV respectively with IOUT = 3mA ?

 

3) Can I achieve 100mV p-p at the o/p by connecting 41.1K resistor at FSADJUST pin ?

 

4) Is there any option of logarithmic (or customized) frequency sweep. Say 1 KHz to 10 KHz in steps of 1 KHz, steps of 10 KHz for 10 KHz to 100 KHz, steps of 100 KHz for 100 KHz to 1 MHz and steps of 1 MHz for 1 MHz to 5MHz.

 

5) I would need similar customized sweeping option for DC bias as well. Any existing solution ?

 

Thanks in advance for your help.

 

Regards,

AG / GT Silicon

 

Message was edited by: Amit Gupta

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