I use hmc821 instead of hmc834,the frequency i need is 1970M,but actually i only obtain maxim frequency is 1860M,and i check TUNE is 5V , it didn't reach the datasheet frequency range from 1720-2080
Hi,
We designed a PCB for @HMC821 frequency synthesizer as much as similar to the one depicted in the datasheet of HMC821. and we load registers as below to obtain 1900MHz RF at the output
reg02 : 00000001
reg06: 0003074a
reg09: 00003264
reg05: …
HMC821's Id (Vcc1,Vcc2) drops slightly when the issue appears (by aproax 2mA, 68mA-2mA = 66mA in total)
Use the ADP150 regulator; good performance, low cost.
Use…
我们在使用ARM控制器配置HMC821LP6CE芯片,开发板加电后,由于不知道SPI到底工作于哪种模式,因此尝试了SPI的两种模式,但无论使用OPEN MODE SPI还是HMC Mode SPI均不能正常读取芯片寄存器的值,SPI读写速率约为600KHz,使用示波器查看MOSI引脚输出信号时序和datasheet一致,查看芯片RF射频输出引脚信号,可以看到大约1GHz的信号。不知道为什么两种方法均不能读取寄存器的值,这样没办法判断是否能正常写寄存器的值。
目前不知道如何排查,期望得到大家的帮助…
This note discusses best practices for use of the Serial Port Interface (SPI) Mode selection feature of HMC PLL and PLLVCO product lines.
The attached FAQ document provides additional information on the use of the PLL+VCO and Clock Timing family of products. Specifically,
the applicable products are:
HMC820LP6CE HMC821LP6CE HMC822LP6CE HMC824LP6CE HMC826LP6CE
HMC828LP6CE HMC829LP6…