I am looking for S parameter file of hittite hmc833lp6ge PLL+VCO
I've attached csv and s1p files for the HMC833 return loss.
The following plot shows the output return loss for the HMC833lp6ge. Figure 19 in the datasheet is the log version of this plot.
dyoung1 thanks but my intention was to get s parameter file of pll.is it poosible to get s parameter file of pll
thanks in advance
dyoung1 thanks a lot for the file
Can you help with the proper way to connect external reference signal to HMC833 eval. board?
I tried to connect a signal in J5 and I removed JP3 but nothing happened?
thank you for your support
You need a few more hardware modifications. To lock the HMC833 directly to an external reference at J5 you must remove the onboard 50MHz VCO (Y1) from the circuit:
Without the above modifications the eval board locks the onboard 50MHz reference VCO to an external 10MHz signal connected at J5. We perform a x5 multiplication since most test equipment generate a 10MHz reference signal. With no reference at J5, the Y1 VCO free-runs at 50MHz+-150ppm which causes inaccuracies in the generated frequency. We include SW1 to select the x1, x5 (default) or x10 reference multiplication factor. This makes the design a bit more flexible allowing 50MHz or 5MHz external signals at J5 if desired.
It works well now, thank you very much.
Excuse my ignorance, but the board worked for some time and now I got a "lost communication" message when I open the software, what do you think the problem is?
Thank you for you support
This type of error is usually caused by incorrect mode selection after power-on. Please see section 1.17.2 in the datasheet for a description on mode selection. Possibly the part may have been damaged -- after power-on the eval board should draw approximately 225mA.
You can try the following procedure:
If you lose comms after loading a register file try loading the default register files included with the eval software. Two registers can cause communication failures if not configured correctly. Reg0Fh bit 6 must be low to enable SDO data and Reg01 bit 1 must be high to enable the PLL.
I tried to reset the IC, when I turn the 5.5v on I got 218mA and when I disable the chip the current became 216mA not 18mA as you said.
Also when I read the register 0h I got 0 or sometimes FFFFF.
And when I measured the voltage at JP5 it was 0.282V and at JP2 it was 0.858V is that means something wrong with the regulator or the PLL IC?
Thank you very much for your support
Check if the regulator is enabled by monitoring "AD4" at the USB interface connector as you toggle "chipEN pin" on the eval software GUI. This pin should toggle between 0V (disabled) and 3.3V (enabled) as you change "chipEN pin".
If the enable works check the regulator outputs by removing JP2/3/4/5 than measuring 3.3V at pin 1 on JP3/4/5 and 5V on pin 1 of JP2. Pin 1 has square pads on the back of the board.
AD4 is equal 4.13V when "chipEN pin" is (enabled) and its equal to 0V when (disabled)
Pin 1 at:
JP1=0.29V (when JP5 is shorted)
Since AD4 changes with "chipEN" the eval software can communication through the USB interface but it looks like both regulators (U1 and U4) are damaged. Only JP2 has the correct voltage.
Can you please suggest me the prober way to solve this problem?
Do I have to buy a new eval board?
Unless you have surface mount rework equipment to replace the regulators I can only suggest a new board is in order. The board was working fine -- did something happen? Maybe the input power spikes above 5.5V at power-on.
Dear Dean dyoung1,
I have HMC833 chip on my new design I didn't use any regulators, I'm using Agilent DC power supply to provide the chip with 2 DC inputs (5v & 3.3v).
The current consumption for the 5v is 133mA and for 3.3v is 67mA.
The problem is when connect the board to the USB interface and run the software I got the "Lost Communication" message.
Could please suggest any solutions?
The power supply current is about right. "Lost Communication" indicates the software is not able to read the chip ID at Register 0x00. This could happen if the HMC833 SPI interface operates in "Open Mode". After power-on the SPI mode is selected using SEN and SCLK input signals.
Check your design has applied 3.3V power to the USB interface board via pins 2 and 4 on the 10 pin header. These pins power the isolators on the USB board. Check the SCLK line is low during HMC833 power-on. Sometimes the SPI outputs on the USB board FTDI chip get stuck high -- try power cycling the USB board and/or unplugging the USB connection.
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