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AD9959DDSSweeper

This labscript device controls the DDSSweeper, an interface to the AD9959 eval board four channel direct digital synthesizer (DDS) using the Raspberry Pi Pico platform.

The DDS Sweeper is described in more detail in E. Huegler, J. C. Hill, and D. H. Meyer, An agile radio-frequency source using internal sweeps of a direct digital synthesizer, Review of Scientific Instruments, 94, 094705 (2023) https://doi.org/10.1063/5.0163342 .

Specifications

The AD9959 evaluation board provides the following:

  • 4 DDS channels
    • 100 kHz - 250 MHz output frequency with 32 bit frequency resolution (~0.1 Hz)
    • Up to 0 dBm output power with 10 bit amplitude resolution
    • Phase control with 16 bit resolution (~48 uRad)

The Pico interface allows the evaluation board parameters to be reprogrammed during a sequence. At this time, stepping of frequency, amplitude, and phase parameters is supported. Parameter ramping is possible, but not currently supported by the labscript device (if support for this is of interest, please open an issue <https://github.com/labscript-suite/labscript-devices/issues>). The Pico interface provides the following:

  • For the Pico 1: 16,656 instructions distributed evenly among the configured channels; 16,656, 8,615, 5,810, and 4,383 for 1, 2, 3, 4 channels respectively.
  • For the Pico 2: 34,132 instructions distributed evenly among the configured channels; 34,132, 17,654, 11,905, and 8,981 for 1, 2, 3, 4 channels respectively.
  • External timing via a pseudoclock clockline.
  • By default, the AD9959 system reference clock is taken from the Pi Pico. If a higher quality clock is needed, the user can provide an external system reference clock to the AD9959. For more details on clocking, see the Usage section.

Installation

On your Raspberry Pi Pico, hold down the "bootsel" button while plugging the Pico into USB port on a PC (that must already be turned on). The Pico should mount as a mass storage device (if it doesn't, try again or consult the Pico documentation). Drag and drop the .uf2 file into the mounted mass storage device. The mass storage device should unmount after the copy completes. Your Pico is now running the DDS Sweeper firmware!

Note that this device communicates using a virtual COM port. The number is assigned by the controlling computer and will need to be determined in order for BLACS to connect to the PrawnDO.

Usage

An example connection table with the default settings of the sweeper:

from labscript import start, stop, DDS, StaticDDS
from labscript_devices.PrawnBlaster.labscript_devices import PrawnBlaster
from labscript_devices.AD9959DDSSweeper.labscript_devices import AD9959DDSSweeper

# prawnblaster for external timing
prawn = PrawnBlaster(
                    name='prawn',
                    com_port='COM7',
                    num_pseudoclocks=1
                    )

AD9959 = AD9959DDSSweeper(
                        name='AD9959',
                        parent_device=prawn.clocklines[0],
                        com_port='COM11',
                        dynamic_channels=2
                        )


chann0 = DDS( 'chann0', AD9959, 'channel 0')
chann1 = DDS( 'chann1', AD9959, 'channel 1')
chann2 = StaticDDS( 'chann2', AD9959, 'channel 2')
chann3 = StaticDDS( 'chann3', AD9959, 'channel 3')


start()

stop(1)

An example connection table that uses the PrawnBlaster and sweeper with three dynamic channels, an external, 100 MHz clock and pll multiplier of 5:

from labscript import start, stop, DDS, StaticDDS
from labscript_devices.PrawnBlaster.labscript_devices import PrawnBlaster
from labscript_devices.AD9959DDSSweeper.labscript_devices import AD9959DDSSweeper

# prawnblaster for external timing
prawn = PrawnBlaster(
                    name='prawn',
                    com_port='COM7',
                    num_pseudoclocks=1
                    )

AD9959 = AD9959DDSSweeper(
                        name='AD9959',
                        parent_device=prawn.clocklines[0],
                        com_port='COM11',
                        dynamic_channels=3,
                        pico_board='pico2',
                        ref_clock_external=1,
                        ref_clock_frequency=100e6,
                        pll_mult=5
                        )


chann0 = DDS( 'chann0', AD9959, 'channel 0')
chann1 = DDS( 'chann1', AD9959, 'channel 1')
chann2 = DDS( 'chann2', AD9959, 'channel 2')
chann3 = StaticDDS( 'chann3', AD9959, 'channel 3')


start()

stop(1)

Clocking

If the Pi Pico is used as the AD9959 system reference clock, pin 21 of the Pi Pico should be connected to the REF CLK input (J9) of the AD9959 eval board. Otherwise, another clock source should be connected to REF CLK input and its frequency provided as the ref_clock_frequency.

Detailed Documentation

.. automodule:: labscript_devices.AD9959DDSSweeper
    :members:
    :undoc-members:
    :show-inheritance:
    :private-members:


.. automodule:: labscript_devices.AD9959DDSSweeper.labscript_devices
    :members:
    :undoc-members:
    :show-inheritance:
    :private-members:


.. automodule:: labscript_devices.AD9959DDSSweeper.blacs_tabs
    :members:
    :undoc-members:
    :show-inheritance:
    :private-members:


.. automodule:: labscript_devices.AD9959DDSSweeper.blacs_workers
    :members:
    :undoc-members:
    :show-inheritance:
    :private-members:


.. automodule:: labscript_devices.AD9959DDSSweeper.runviewer_parsers
    :members:
    :undoc-members:
    :show-inheritance:
    :private-members: