QDAC-II: Ultra-low-noise 24-Channel DAC
A state-of-the-art 25-bit voltage source
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QDAC-II is a 24-channel high-precision low-noise voltage generator for DC and intermediate-frequency control of quantum electronics and QPUs, including gate electrodes and flux bias coils for qubits. With current sensing and AWGs on each channel, a very versatile instrument that can be used for gate-leakage detection, fast tune-up algorithms, providing stable operation points, and many more applications.
Precision Voltage Generators
QDAC-II is a high-precision, 25-bit resolution, ultra-low-noise DAC with 24 voltage channel generators with a 1 MS/s sample rate and a step size of 0.12 μ. Each of the 24 channels has five voltage generators working in parallel: One for DC, a sine generator, a triangle generator, a square wave generator, and an arbitrary waveform generator.
Fast Tune-Up and Operation Point Control
Performs fast multi-dimensional gate voltage sweeps using a 300 kHz output filter. Once at your operation point, QDAC-II is switchable to an ultra-low noise DC voltage with a 10 Hz output filter and 25-bit resolution, with minimal transients.
Complete and Scalable Solution
QDAC-II offers a high-performance and versatile solution with an endless number of applications. Multiple OPX+ and QDAC units can be stacked and synchronized to operate as one advanced quantum control system.
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Key Features
- Ultra-low noise and ultra-stable 24-channel voltage source
- Unique low pass filter with 3 ranges that can be switched between with minimal transients: cut-off 300 KHz, cut-off 10 KHz, and cut-off 10 Hz
- 25-bit resolution in DC mode (10 Hz cut-off), 20-bit in medium bandwidth mode (10 kHz cut-off), and in high bandwidth (fast) mode (300 kHz cut-off)
- One million samples per second per channel
- Each channel has multiple standard waveform generators and an arbitrary waveform generator
- Individual high-resolution low-frequency current sensors on every channel, measuring current simultaneously on all channels
- Advanced triggering and synchronization functions between channels with sub-microsecond precision
Efficiently controlling multiple frequency-tunable transmon qubits can be achieved with QM's OPX and QDevil's QDAC. QDAC's high-precision and low-noise bias voltage ensures accurate qubit frequency control without compromising coherence times, while QM's OPX offers advanced control solutions that are user-friendly and require minimal technical expertise. I highly recommend using OPX and QDAC together to streamline your lab processes and advance your quantum computing research.
Diraq is delighted to partner with Quantum Machines, and credits their OPX control system, with its real-time capabilities, as instrumental in achieving the results outlined in our research. The ease of programming sequences in QUA significantly streamlined the experimental process
Benefits
Multiple Waveforms
Each of the 24-channels has five voltage generators working in parallel: one for DC, a sine, triangle and square wave generator, and an arbitrary waveform generator (1 million points/second)
Built-in Sensitive Current Sensors
Each channel includes a DC current sensor with a resolution down to a few tens of pA, typically used for gate leakage detection and with sample rates up to 3 kHz
Ultra Stable Voltage Source
Low noise floor (<20 nV/√Hz), ensuring reliable qubit operation points
Reduces Experiment Setup Costs
Built-in function generators (including AWG) and current sensors reduce the need for additional instruments
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