SRI 6000 series Page 1 of 5 

National Institute of Standards & Technology 

Specifications 

Standard Reference Instrument Series 6000 

Programmable Josephson Voltage Standard 

Description: The Programmable Josephson voltage standard (PJVS) is an instrument that 

generates stable, quantum-accurate, direct-current (DC) voltages that are programmable over the 

range from 10 volts to +10 volts. The quantum accuracy of these voltages is derived from the 

Josephson Effect such that every superconducting Josephson junction in the PJVS circuit produces 

a voltage precisely proportional to the frequency of the applied microwave bias signal. 

The PJVS with its quantum accurate dc voltages can serve as a primary voltage standard with 

accuracy of parts in 1010 (determined through intercomparison with another quantum voltage 

standard) or as a stable, programmable source for precision measurements, metrology experiments 

or calibrations. For example, the PJVS can be used to calibrate Zener references (typically within 

few parts in 108 relative accuracy depending on the measurement instruments and Zener noise) as 

well as the amplitude-dependent gain and linearity of digital voltage meters. 

The PJVS is also capable of generating stepwise-approximated waveforms or sine waves with a 

10 % to 90 % transition duration between voltage steps that is less than 6 microseconds. The AC 

voltage of the stepwise waveforms do not have quantum accuracy because the transitions between 

the steps are bias dependent. A differential-sampling measurement technique with an integrating 

sampling digital voltmeter is used with the step-wise waveforms to calibrate the ac voltage of 

commercial voltage calibration sources at frequencies up to a few hundred hertz with a typical 

measurement uncertainty of a few parts in 107, depending on the phase and amplitude stability of 

the source. 

Design, assembly and technical measurements leading to the production of this SRI were 

performed by Superconductive Electronics Group members from the NIST RF Technology 

Division. 

Support aspects involved in the issuance of this SRI were coordinated through the NIST Office of 

Reference Materials.

 Paul D. Hale, Chief 

 RF Technology Division 

 Steven J. Choquette, Director 

Gaithersburg, MD 20899 Office of Reference Materials 

Certificate Issue Date: 21 January 2022 Material Measurement Laboratory 

 
SRI 6000 series Page 2 of 5 

Specifications: NIST provides the PJVS as Standard Reference Instrumentation (SRI) with 

performance that is equivalent to that of NIST systems in terms of quantum accuracy and precision 

measurement capability, provided that operators follow recommended best practices and perform 

intercomparisons with comparable quantum-based voltage sources. The NIST PJVS SRI is offered 

in a range of different configurations, from individual 10 V or 2 V PJVS cryopackaged chips that 

contain the superconducting integrated circuit to fully integrated PJVS systems where the chip is 

cooled by either liquid-helium or a cryocooler refrigerator to the operating temperature at which 

the PJVS circuit becomes superconducting. The PJVS chips are fabricated and packaged by NIST 

in accordance with existing and established fabrication protocols. All the system configurations of 

the PJVS SRI are constructed primarily from commercially available components and include 

software that optimizes the system performance and ensures that it produces quantum-accurate 

voltages. 

NIST researchers continue to develop and improve the PJVS systems and measurement 

techniques. The PJVS circuits and systems and associated measurement capabilities are identical 

to those of NIST systems at the time of acquisition. NIST is providing the PJVS through the SRI 

program with prices derived such that NIST is reimbursed for all costs associated with duplicating 

the current versions of NIST systems. Prices do not include support, training, or on-site installation 

and qualification. The customer should contact the Standard Reference Instrument office 

(srminfo@nist.gov) for costs for these services. 

The PJVS circuits and systems have the following specifications and features.1

A) A cryopackaged chip that is tested and demonstrated to produce stable, quantumaccurate, programmable voltages over the range from 10 volts to +10 volts with a 

minimum current range of 1.0 mA that is determined with a 3 μV measurement 

threshold. 

B) The capability to generate stepwise-approximated voltage waveforms such that the 

transition duration between steps is less than six microseconds. Differential sampling 

measurements may be performed with the SRI 6000 system but require additional 

hardware and software. Interested parties should contact NIST for further details. 

C) A majority of system components that are commercially available. 

D) Operating frequency between 15 GHz and 22 GHz. 230 μV minimum voltage resolution 

of the least significant bit of 6 Josephson junctions, and 1 nV voltage tuning through 1 Hz 

frequency resolution (for output voltages larger than 200 mV). 

E) A leakage resistance to ground of at least 50 G and automated leakage resistance to 

ground measurement module. System delivered with shielded bias cables; custom made 

for low leakage current performance. Uncertainty due to leakage may be bounded by 

multiplying the leakage current (~ 10 V/Leakage resistance) by the lead resistance (~1 

Ohm). Thus for 10 G leakage resistance, the uncertainty due to leakage is < 1 nV. 

F) NIST-designed custom dc current bias electronics and isolated linear power supply, a NI 

embedded controller (PC) & a widescreen flat panel monitor, OR external computer, 

electronic and hardware integration components, cables, wrenches, and equipment rack. 

1 Certain commercial equipment, instruments or materials are identified in this certificate to adequately specify the 

experimental procedure. Such identification does not imply recommendation or endorsement by the National Institute of Standards 

and Technology, nor does it imply that the materials or equipment identified are necessarily the best available for the purpose. 
SRI 6000 series Page 3 of 5 

G) A single-node license of the “PJVS-Core” system software that automatically evaluates 

and optimizes the performance of the chip and the system electronics in order to ensure 

that the voltages are quantum accurate and have the largest current range. 

H) “ZENERcal” application software that provides dc calibrations of various voltage sources 

such as Zener references. 

I) “DVMcal” application software that provides dc gain and linearity calibrations of various 

volt meters, such as Keysight 3458A, Keysight 34420A, Fluke 8508A, Fluke 8588A, 

Fluke 8558A, Keithley 2182, and Keithley 2002. DVMcal includes also a ratio 

calibration function of the Fluke 8508A, Fluke 8588A, and the Keysight 3458A. 

J) The capability to externally control of the PJVS through an Ethernet connection 

(LabviewTM data socket) with user commands in order to enable the PJVS to be 

integrated with customer software for other applications. 

Delivery: Delivery and installation dates will be determined on a case-by-case basis in 

coordination with the customer and based on the availability of components and NIST staff. 

Shipping: Unless otherwise agreed by the parties, shipping terms shall be EXW (Incoterms 

2010). NIST will prepare packaging for shipment of the PJVS SRI. Shipping crate dimensions 

and weight will be included in each quote. Customers are responsible for arrangement of 

shipping pickup at NIST as well as all customs duties and import fees (HTC 9030.33.0040). 

Technical requirements at installation site: Customers must provide the following: 

A) A 10 MHz reference signal whose frequency is accurate to a part in 1010 or better. 

B) Customs related clearances, documents, payments, and fees. 

C) Liquid helium (for liquid-helium-cooled systems only) for both the on-site qualification 

as well as for daily operation. 

D) Appropriate power and utilities for compressors (for cryo-cooled systems only), 

including power and connectors for RDK-101DP: single-phase 15.5 A, 208 V, 60 Hz (or 

13 A, 200 V, 50 Hz) power or RDK-205D: 3-phases, 200 V, 4.6-5.6 kW at 60 Hz (3.6-

4.8 kW at 50 Hz) power, and cooling water: (4-9) L/min at (5-25) °C (for the watercooled compressor only). 

E) Acquiring the commercial instruments and components that are to be integrated into the 

PJVS system (as specified in the PJVS configuration descriptions). 

F) Providing, as the customer deems necessary, the following additional instruments that are 

typically used for calibration measurements and are currently supported by existing PJVS 

software: 

a. A dedicated nanovoltmeter (in addition to the Keysight 34420A voltmeter 

provided with the PJVS system), such as either Keysight 34420A (preferred), 

Keysight 3458A, or Keithley 2182A are recommended, 

b. Customer’s Zener dc reference standard or standards. 

c. A DATAPROOF scanner (with GPIB module E installed), if the customer 

chooses to implement automated simultaneous calibration of multiple Zener 

voltage standard references. 

Users of this SRI should ensure that the Specifications Certificate in their possession is current. This can be accomplished by 

contacting the Office of Reference Materials: telephone (301) 975-2200; e-mail srminfo@nist.gov; or via the Internet at 

http://www.nist.gov/sri. 
SRI 6000 series Page 4 of 5 

Programmable Josephson Voltage Standard (PJVS) System Configurations 

SRI 6000 series 

SRI 6000e: Cryo-cooled 10V PJVS, with water-cooled compressor 

a. DS instrument SG22000PRO microwave synthesizer with frequency up to 22 GHz  

b. Sumitomo RDK‐101DP‐HC4E2 or Sumitomo RDK‐205D‐F‐40

c. Cryopackaged 10V PJVS chip

d. Aldetec ALS04541 or Mini‐circuits ZVE‐3W‐183+ or equivalent microwave amplifier

e. Keysight 34420A nanovoltmeter

f. Lakeshore 325 or SRS CTC100 temperature controller

g. National Instruments: PXIe‐1062Q chassis, PXIe‐8821 Windows 10 controller and 8 GB RAM, 6 each PXI‐6230

DAC cards, PXIe‐6672 timing card, & GPIB‐USB HS+ (EC) OR cDAQ‐9178, NI 9403, 2 each NI 9264, NI 9238,

GPIB‐USB HS+ (EC), Laptop computer, & USB isolator.

h. NIST‐designed JVS‐650 OR JVS‐700 dc current bias electronics and isolated linear power supply

SRI 6000h: Cryo-cooled 10V PJVS, with water-cooled compressor, without synthesizer 

a. Customer provides one of the recommended microwave synthesizers, either the Keysight E8257D or E8257N

or an equivalent

b. Sumitomo RDK‐101DP‐HC4E2 or Sumitomo RDK‐205D‐F‐40

c. Cryopackaged 10V PJVS chip

d. Aldetec ALS04541 or Mini‐circuits ZVE‐3W‐183+ or equivalent microwave amplifier

e. Keysight 34420A nanovoltmeter

f. Lakeshore 325 or SRS CTC100 temperature controller

g. National Instruments: PXIe‐1062Q chassis, PXIe‐8821 Windows 10 controller and 8 GB RAM, 6 each PXI‐6230

DAC cards, PXIe‐6672 timing card, 2x1 m, and 1x2m GPIB cables, & GPIB‐USB HS+ (EC) OR cDAQ‐9178, NI

9403, 2 each NI 9264, NI 9238, GPIB‐USB HS+ (EC), or external computer, & USB isolator.

h. NIST‐designed JVS‐650 dc current bias electronics and isolated linear power supply

SRI 6000i: Cryo-cooled 10V PJVS, with air-cooled compressor 

a. DS instrument SG22000PROmicrowave synthesizer with frequency up to 22 GHz  

b. Sumitomo RDK‐101DP‐HC4A2 or Sumitomo RDK‐205D‐FA‐40

c. Cryopackaged 10V PJVS chip

d. Aldetec ALS04541 or Mini‐circuits ZVE‐3W‐183+ or equivalent microwave amplifier

e. Keysight 34420A nanovoltmeter

f. Lakeshore 325 or SRS CTC100 temperature controller

g. National Instruments: PXIe‐1062Q chassis, PXIe‐8821 Windows 10 controller and 8 GB RAM, 6 each PXI‐6230

DAC cards, PXIe‐6672 timing card, 2x1 m, and 1x2m GPIB cables, & GPIB‐USB HS+ (EC) OR cDAQ‐9178, NI

9403, 2 each NI 9264, NI 9238, GPIB‐USB HS+ (EC), external computer, & USB isolator.

h. NIST‐designed JVS‐650 dc current bias electronics and isolated linear power supply

SRI 6000l: Cryo-cooled 10V PJVS, with air-cooled compressor, without synthesizer 

a. Customer provides one of the recommended microwave synthesizers, either the Keysight E8257D‐528 or

E8257N or an equivalent  

b. Sumitomo RDK‐101DP‐HC4A2 or Sumitomo RDK‐205D‐FA‐40

c. Cryopackaged 10V PJVS chip

d. Aldetec ALS04541 or Mini‐circuits ZVE‐3W‐183+ or equivalent microwave amplifier
SRI 6000 series Page 5 of 5 

e. Keysight 34420A nanovoltmeter

f. Lakeshore 325 or SRS CTC100 temperature controller

g. National Instruments: PXIe‐1062Q chassis, PXIe‐8821 Windows 10 controller and 8 GB RAM, 6 each PXI‐6230

DAC cards, PXIe‐6672 timing card, & GPIB‐USB HS+ (EC) OR cDAQ‐9178, NI 9403, 2 each NI 9264, NI 9238,

GPIB‐USB HS+ (EC), external computer, & USB isolator.

h. NIST‐designed JVS‐650 dc current bias electronics and isolated linear power supply

SRI 6000m: Cryopackaged 10V PJVS chip 

SRI 6000n: Cryopackaged 2V PJVS chip 

SRI 6000o: Upgrade existing NIST-installed Liquid-helium-cooled PJVS to Cryocooler with watercooled compressor 

a. Sumitomo RDK‐101DP‐HC4E2 or Sumitomo RDK‐205D‐F‐40

SRI 6000p: Upgrade existing NIST-installed Liquid-helium-cooled PJVS to Cryocooler with air-cooled 

compressor 

a. Sumitomo RDK‐101DP‐HC4A2 or Sumitomo RDK‐205D‐FA‐40

SRI 6000q: Liquid helium-cooled 10V PJVS without dewar 

a. Customer provides a CMSH‐100 Dewar or other dewar and fixtures compatible with cryoprobe

b. DS instrument SG22000PROmicrowave synthesizer with frequency up to 22 GHz  

c. HPD JVS‐650B cryoprobe

d. Cryopackaged 10V PJVS chip

e. Aldetec ALS04541 or Mini‐circuits ZVE‐3W‐183+ or equivalent microwave amplifier

f. Keysight 34420A nanovoltmeter

g. National Instruments: PXIe‐1062Q chassis, PXIe‐8821 Windows 10 controller and 8 GB RAM, 6 each PXI‐6230

DAC cards, PXIe‐6672 timing card, & GPIB‐USB HS+ (EC) OR cDAQ‐9178, NI 9403, 2 each NI 9264, NI 9238,

GPIB‐USB HS+ (EC), external computer, & USB isolator.

h. NIST‐designed JVS‐650 dc current bias electronics and isolated linear power supply

SRI 6000t: Liquid helium-cooled 10V PJVS, without synthesizer or dewar 

a. Customer provides one of the recommended microwave synthesizers, either the Keysight E8257D or E8257N

or an equivalent

b. Customer provides a CMSH‐100 Dewar or other dewar and fixtures compatible with cryoprobe

c. HPD JVS‐650B cryoprobe

d. Cryopackaged 10V PJVS chip

e. Aldetec ALS04541 or Mini‐circuits ZVE‐3W‐183+ or equivalent microwave amplifier

f. Keysight 34420A nanovoltmeter

g. National Instruments: PXIe‐1062Q chassis, PXIe‐8821 Windows 10 controller and 8 GB RAM, 6 each PXI‐6230

DAC cards, PXIe‐6672 timing card, & GPIB‐USB HS+ (EC) OR cDAQ‐9178, NI 9403, 2 each NI 9264, NI 9238,

GPIB‐USB HS+ (EC), external computer, & USB isolator.

h. NIST‐designed JVS‐650 dc current bias electronics and isolated linear power supply