# Two channel Phase synchronized RF output from RFSoC 4\*2 board

**URL:** <https://discuss.pynq.io/t/two-channel-phase-synchronized-rf-output-from-rfsoc-4-2-board/8817>\
**Category:** Support\
**Created:** [October 17, 2025, 11:01am UTC](https://discuss.pynq.io/t/two-channel-phase-synchronized-rf-output-from-rfsoc-4-2-board/8817 "2025-10-17T11:01:18Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![sujit](https://avatars.discourse-cdn.com/v4/letter/s/35a633/32.png) [@sujit](https://discuss.pynq.io/u/sujit)\
**Post date:** [October 17, 2025, 11:01am UTC](https://discuss.pynq.io/t/two-channel-phase-synchronized-rf-output-from-rfsoc-4-2-board/8817/1 "2025-10-17T11:01:18Z")

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I want to generate two RF output of same frequency and same amplitude in two channels of the RFSoC board but they should be perfectly phase synchronized. Currently I am not able to generate the phase synchronization. The frequency of the channels are about 1 GHz. Can anyone help me. I can provide the code if needed.

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**Author:** ![sujit](https://avatars.discourse-cdn.com/v4/letter/s/35a633/32.png) [@sujit](https://discuss.pynq.io/u/sujit)\
**Post date:** [October 29, 2025, 2:35pm UTC](https://discuss.pynq.io/t/two-channel-phase-synchronized-rf-output-from-rfsoc-4-2-board/8817/2 "2025-10-29T14:35:24Z")

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Hi everyone,

As I mentioned previously, I’m trying to generate two **phase-synchronized RF pulses** from the **two DAC output channels** (DAC\_A and DAC\_B) of an **RFSoC board**. I’m using an **external 10 MHz reference clock** to generate the signals on both channels.

However, I’m not getting the synchronized output I expected. I suspect that the two DAC channels might still be using different reference clocks internally. Even with the external clock connected, the outputs from DAC\_A and DAC\_B are not synchronized at high frequencies (around 980 MHz).

According to the RFSoC board manual:

> “The external clock input allows an external time base to be used, and the SYNC input allows synchronization across multiple RFSoC boards. If the SYNC input is needed, OUT1 and OUT5 of the LMK must be enabled to synchronize the downstream LMXs (OUT1 and OUT5 are powered off by default).”  
> _(Page 7, RFSoC Board Manual)_

My question is: **Do I need to enable OUT1 and OUT5 to achieve synchronized outputs from two DAC channels on the same RFSoC board** , or is that only necessary when synchronizing across multiple boards?

For reference, I’m using:

- **PYNQ version:** 3.0.1

- **QICK version:** 0.2.369

- **Environment:** Jupyter Notebook

I’ve attached the code I’m using to generate the pulses.

Any guidance or suggestions on how to achieve proper synchronization between the two DAC channels would be greatly appreciated!

[Two\_ch\_phase\_synchronized\_RF.ipynb](https://discuss.pynq.io/uploads/short-url/99ZRCuKyUI9vMohBo0wsGEOwCAZ.ipynb) (5.3 KB)

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**Author:** ![EricMac](https://avatars.discourse-cdn.com/v4/letter/e/34f0e0/32.png) [@EricMac](https://discuss.pynq.io/u/EricMac)\
**Post date:** [July 17, 2026, 1:46pm UTC](https://discuss.pynq.io/t/two-channel-phase-synchronized-rf-output-from-rfsoc-4-2-board/8817/3 "2026-07-17T13:46:35Z")

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Hi, did you solve this? Thanks