LMX2595: LMX2595的斜坡配置斜坡时长，台阶时长和台阶调频值△f怎样配置？

Yongwang cheng

Part Number: LMX2595

LMX2595的datasheet中给出的自动斜坡例子中，RAMP0_INC =13422, 根究公式可得

(2000 MHz) / (50 MHz) × 2^24/ 50000 = 13422

此公式的具体解释是什么？
具体斜坡的计算：斜坡时长和斜坡△f怎样设计计算的？

3 年多前

0 Kailyn Chen 3 年多前

TI__Guru**** 295050 points

您好，根据数据手册中的例子，Suppose user wants to generate a sawtooth ramp that goes from 8 to 10 GHz in 2 ms (including calibration breaks) with a phase-detector frequency of 50 MHz. Divide this into segments of 50 MHz where the VCO ramps for 25 µs, then calibrates for 25 µs, for a total of 50 µs. There would therefore be 40 such segments which span over a 2-GHz range and would take 2 ms, including calibration time.

首先扫频范围为2GHz=2000Mhz，2ms内完成扫频。fpd=50Mhz，如果每50us扫频一次。

这样理解的话，2ms完成，一共需要2ms/50us次的扫频。那么2000Mhz的扫频范围话，

ramp increment即RAMPx_INC=2000Mhz/2ms/50us.

我是这么理解的，和数据手册的公式有出入，我再想一下。