How stepped triangle waveform generation

Hi Eddy,

Thank you for your interest in our products. We received your question and will be answering it as soon as possible. We appreciate your patience.

Regards,
Julian

Hi Julian

I waited long time your answer.

First of all, Please support of Register value below question.

1.We try to generate a stepped triangle waveform using the LMX2492.

RAMP 0: dT(Duration) 48us, dF: 500MHz (up)

RAMP 1: dT : 48us,           dF: 500MHz (down)

Best regards,

Eddy (eddy.lee@avnet.com)

Eddy,

We need to know the phase detector frequency to program this. Since I do not know, I will assume 100 MHz and then use this as an example.

For this waveform, I would set:

RAMP0_LEN = 48 us x (100 MHz) = 4800
RAM0_INC = (500MHz/100MHz)*16777216/4800 = 17476
RAMP0_NEXT = 1 (RAMP1)

RAMP1_LEN = 4800
RAMP1_INC = 2^30 - 17476 = 1073724348
RAMP1_NEXT = 0 (RAMP0)

The CodeLoader has a special tab for the ramp calculator that you might find useful for this. Note also that I assumed that the phase detector was 100 MHz. If it is different, then these calculations would change.

Regards,
Dean

Hi Dean

Thank you for your answer.

But customer request is confirm of MUXOUT wave regularly.

Sometimes is not regularly output wave of MUXOUT.

Only showed 2 and 4 MUXOUT at rising time, but 1,3,5 is not showed.

Please send me your comment.

Best regards,

Eddy

Eddy,
Here are a few ideas:
1. Use the MUXout pin as "Output RAMP0 Active" and then you can use the rising edge for RAMP0 and the falling edge for RAMP1. Another choice is to use a separate pin for RAMP1

2. If you want a narrow pulse then another choice is to actually make this with 4 RAMPS.
Make:
RAMP0_Length = 0.01 us
RAMP0_FLAG = Flag 0
RAMP0_NEXT = RAMP1

RAMP1_LENGTH = 47.99 us
RAMP1_FLAG = Disabled
RAMP0_NEXT = RAMP2

RAMP2_LENGTH = 0.01 us
RAMP2_FLAG = FLAG0
RAMP0_NEXT = RAMP3

RAMP3_LENGTH = 47.99 us
RAMP3_FLAG=Disabled
RAMP0_NEXT = RAMP0