LMX2594EVM: Constraint for using the maximum RAMP_CLK frequency

For example,

I want to ramp from 2.4G to 2.5G, as step size of 1MHz.

But on fast RAMP_CLK frequency (10 kHz),

it seems work just only from 2.4G to 2.45G, and the total number of step is just only 50 (not 100).

About figure 10 of LMX2594 datasheet,

Is the ramping is on auto or manual mode?

Hi There,

Figure 10 is calibration-free automatic ramping.

How long do you want to sweep from 2.4G to 2.5GHz?

Thank you.

On Manual ramping and the step height of 1MHz,
I want to sweep in 1 ms.

In additional, the sweep range (2.4~2.5 GHz) and the step height (1 MHz) is not about the VCO but the final RF output.

Furthermore, actually, I want to know the maximum speed of ramping.

Especially, I want to use manual ramping as possible.

Hi There,

2.4G to 2.5GHz at output, 1MHz step size, ramp period = 1ms

- there are 100 step in 1ms, duration for each ramp is 10µs, so RAMPclk frequency is 100kHz

- VCO is running between 9.6G to 10GHz. Ramp range is 400MHz, so there will be multiple VCO calibration during the ramp period. However, 10µs is not enough to complete a calibration. Also, during calibration, there will be big glitches. 

I can capture some plots for your reference tomorrow.

Thank you.

If 1 ms is not possible,

what is the maximum speed of ramp?

(What is the minimum time of ramp?)

And, on auto ramp mode,

what is the maximum speed?

Thank you.

Hi There,

are you looking for a linear ramp

or you can accept "staircase" ramp?

The glitches above is due to VCO calibration. The steps (flat region) is use to allow the device to complete a VCO calibration. Duration of this step should be at least 10µs. 

Hi.

Linear is better.

The figure bellow is about manual ramping with 4 MHz step height and  4 kHz RAMPclk.

Is The glitches in the figure also due to VCO calibration?

Thank you.

Hi There,

Yes, look like they are. What is the Threshold setting?