Programmable TTL and Direct Digital Synthesis
RF Pulse Generator
PulseBlasterDDSTM is a
general-purpose, intelligent, programmable, RF
and TTL/CMOS pulse/pattern generator system
(USB board). The PulseBlasterDDSTM
series of Intelligent Pulse Generation boards
from SpinCore Technologies, Inc., couples
SpinCore’s unique Intelligent Pulse Timing
Processor core, dubbed PulseBlasterTM,
with Direct Digital Synthesis (DDS) technology
for use in system control and radio-frequency
(RF) pulse generation. The PulseBlasterTM
processor, implemented in state-of-the-art
programmable logic, provides all the necessary
timing control signals required for overall
system control and pulse
synchronization. By adding DDS features,
PulseBlasterDDSTM can now meet all
the excitation/stimuli needs of demanding
users. PulseBlasterDDSTM provides
users the ability to control their systems
through the generation of both digital control
signals and fully synchronized excitation RF
pulses from a small form factor PC board,
providing users a compelling price/performance
proposition unmatched by any other device on
the market today.
presents the general architecture of the
PulseBlasterDDS-I-300 system. The major
building blocks are the DDS Core and the Pulse
Programming and Timing Processor Core (PP
Core). The DDS Core contains a Numerically
Controlled Oscillator (NCO), 8 programmable
phase registers, 1024 programmable frequency
registers, the AWG (Arbitrary Waveform
Generator), and the adjustable
attenuator. The PP Core controls the
timing of the gating pulses and provides the
necessary control signals for frequency and
phase registers. The DDS and PP cores
have been integrated onto a single silicon
chip. High performance DAC chips and
high current output amplifiers complement the
Benefits of DDS Technology
Generation of any frequency from DC
(Direct Current) to 1/2 reference clock
oscillator in milliHertz tuning steps (32
bit digital resolution)!
Agile relative phase control using up to 8
programmable phase registers per channel,
12-bit phase resolution. Pipeline
delay of only 3 reference clock cycles.
Agile, phase coherent, "zero-time"
frequency switching using 1024 independent
Greater immunity to parameter drift due to
What does SpinCore's
Intelligent Pattern Generation give users?
Timing resolution of 13.3 ns with a 50 MHz
external clock (NOTE: Timing resolution of
2.5 ns is available on non-DDS, TTL-only
PulseBlasterESR boards operating up to 400
4 independent output bits.
Simple instruction set.
Memory space for up to 4k program words
(VLIW, 80-bit wide).
External hardware and software triggering.
3.3 V digital TTL/CMOS outputs, 25 mA per
pin. Output bits can be combined to
increase the max. load current.
Small size and low power consumption.
Low level and high level programming
Free technical support; extended support
This exciting product comes with one analog
output channels and 4 TTL/CMOS channels, all
independently controlled and
synchronized. The analog channel
can output RF/IF frequencies down to
programmable DC levels. By providing multiple
options, PulseBlasterDDSTM can be
your complete excitation device for NMR, NQR,
MRI, or related resonance and test
technologies. If more output channels
are required, multiple boards can be
synchronized to provide as many digital output
bits or RF/IF channels as necessary. The
frequency and phase of the RF pulses generated
by the DDS output channel are under the
complete control of the user and are specified
through software programming. Digital sampling
rates of the output waveforms up to 300 MHz
External Triggering and
PulseBlasterDDSTM can be triggered
and/or reset externally via dedicated hardware
lines. The two separate lines combine
the convenience of triggering (e.g., in
cardiac gating) with the safety of the
"stop/reset-to-zero" line. The required
control signals are active low (or short to
ground). The design also allows for
multiple boards to be synchronized, easily
extending the available output pattern to more
bits and/or more RF/IF channels. The
"Wait-for-event" feature is standard.
Complex, high-speed, multi-channel
pulse, pattern, and word generation.
Customers’ applications have included
Complete high IF digital excitation system
for high field NMR/MRI (just add mixers!).
Complete bench test equipment for
solid-state NMR probes (just add mixer and
power amplifier!) - eliminates the need for
wasting the precious magnet time.
Build a multi-qubit NMR quantum computing
device at a fraction of the cost of other
Use it for all-digital CRAMPS, SFAM, and
other "exotic" solid-state NMR experiments.
Build a lock system.
Build a demostration NMR system with/for
Use it for Senior-Project and Masters'
Use with your microcoil probe.
Build and control your own equipment for
"hyphenated" experiments, LC-NMR, etc.
pre-programmed RF generator customized for
NMR/MRI decoupling applications. To
simplify the pulse-sequence programming,
WALTZ and MLEV decoupling sequences are
hard-coded via firmware and can be selected
with an external TTL signal. The RF
output frequency and pulse lengths can be
controlled via a simple ASCII RS232 serial
interface. The RF output power is
approx. 10 dBm.
Clock Generator. Single
square-wave output of DDS-derived
frequencies, 32 bits of frequency precision
(141 mHz at 300 MHz reference oscillator
frequency), may be used for driving digital
systems as a digital clock generator;
simplified programming interface.
To complement the power and performance of
the PulseBlasterDDSTM board, the
software programming of the board is
straightforward. The programming
architecture, based on the
Very-Long-Instruction-Word (VLIW) concept,
assures that all RF and DAC events are always
properly synchronized with the timing control
signals generated by PulseBlasterTM
pulse programmer core. The 32k memory
depth and powerful flow control statements
allow the most complicated patterns/sequences
to be executed with ease. The
PulseBlasterDDSTM board can run
under Microsoft Windows operating systems,
including XP. The control software can
be compiled to operate under other operating
systems as well.
This is a demonstration of the simultaneous
frequency and amplitude sweeping capabilities
of the SpinCore Technologies'
PulseBlasterDDS-I-300. The video shows a
chirped pulse with a frequency sweep from 80
to 2 MHz and a Gaussian amplitude profile.