I meet a problem about PLL chip's controlling .
I use TMS320F28335 (DSP) to control the HMC833 (PLL) . I have checked the hardware and software over and over again. Both of them are correct . Furthermore, I confirm the clock of SPI is lower than 10MHz through delay function . But the signal is still not appeared.
The same PLL , I use MCU to control it . It output correctly. And I use ARM to control it , the output is also correct.
MCU,ARM and DSP is different in system clock . The system clock of MCU and ARM is lower than 30MHz. The system clock of DSP is 125 MHz. But I have decreased the clock of SPI through delay function.
It's worth paying attention to the SPI line, it's guide line soldering and not PCB wiring. Concerning this , I have decrease the SPI clock cycle in 2.5 ms.
I really don't know where I didn't notice . Can you give me some suggestions.
I have a issue . I want to design a TDD transceiver . I choose the HMC392ALC4 as LNA. The chip of HMC392ALC4 need to be controlled in the mode of TDD. It need to be powered on and off.But I didn't find the response time in the datasheet. Can you help me confirm the response time of Powering on and off . Thanks very much .
Look forward to your good message.