Other Parts Discussed in Thread: LMX2572
Tool/software:
Hello, we are research team looking to use the sweep function on the LMX2752 chip for quantum applications. We want to use this chip in our publishable work however we are not getting the expected output.
We have tried various configurations and setups including:
- Custom LMX2572 PCB with a microcontroller and SPI
- LMX2572 EVAL with TICS Pro
- Tics pro with custom LMX PCB
We are unable to generate the default 3GHz output, nor are we able to read back register values in any of the configurations. Additionally, we observe around 245mA of current draw, instead of the stated max 150mA on the EVAL board.
Using TICS Pro We used the default configuration of Default Mode 2018-4-24, set the MUXout_SW Switch 1 and Switch 2 to Make and Break respectively (Section 2.7 of datasheet), and set the MUXOUT_LD_SEL to Readback (Section 3.2.6). Then we set register 44 to a known value (0x1FA3), write all registers, and then used the "read back register" function. Please note that after writing all registers the current draw jumps from 245mA to 260mA.
Trying to read back a register yields only zeroes in this state. (See image below).
We developed our own PCB at first and encountered the same issues as before. Testing our own made PCB with the green devboard continued to yield the same problem of no frequency output and the inability to read back registers.
If you could provide any insight on how to read back registers or output the correct signal, it would be much appreciated. Please let us know if you need more information.
