Our Product Range
RADFET, RADIATION DETECTION SENSORS AND DOSIMETRY SYSTEMS
The Varadis radiation detection sensor, called RADFET (Radiation Sensing Field Effect Transistor), is a discrete p-channel MOSFET optimized for radiation sensitivity. This microelectronic chip, specially engineered to be sensitive to high energy (ionizing) radiation.
Varadis cost-effective RADFETs are small, robust, require no power to detect radiation and can be easily integrated into radiation dosimetry applications.
You can choose to use an individual RADFET for integration into your design, or a Read-Out Module which provides an optimized RADFET read-out while cutting development time and cost.
Why the Varadis RADFET?
- Smallest radiation dosimetry sensor on the market with a large dynamic range
- Work effectively after significant radiation events tested to >3000 cGy
- Combine the best features of active and passive detectors
- Designed to work in both passive zero power consumption and in active modes
- Not impacted by catastrophic event blackouts, unlike active powered detectors
- Varadis components and systems are easily integrated into wireless networked infrastructures
RADFET DIGITAL READ-OUT MODULE
Designed in partnership with the European Space Agency (ESA), VT-DRM(S) is a total ionizing dose (TID) measuring module aimed at providing an optimized RADFET read-out for various RADFET technologies. The VT-DRM(S) utilizes 100 nm and 400 nm RADFETs in various sense modes, covering both read-out and irradiation (sense) mode.
The module outputs a digitized threshold voltage, which is directly related to accumulated radiation dose. Designed to compensate for threshold voltage drift due to temperature, VT-DRM(S) provides a stable readout over a large temperature span. VT-DRM(S) can be easily integrated with the host. VT-DRM(S) communicates with the host via standard SPI protocol or isoSPI.
RADFET READ-OUT MODULE
Each RADFET Read-out Module, which contains a RADFET and key circuitry for its readout, can be easily integrated into your system by soldering directly onto the PCB or via a standard through-hole header connector.
The module outputs a buffered analog voltage (RADFET threshold voltage), which is related to the accumulated radiation dose of the RADFET.
Specially designed for and optimized around the Varadis RADFET, the current source for the RADFET Read-Out Module is individually adjusted for each part to minimize RADFET threshold voltage drift due to temperature.
The threshold voltage of the RADFET is buffered for easier integration with standard analog to digital converters, significantly simplifying your electronics design. Both Read-out and Irradiation (sense) modes of RADFET operation are supported.
You can easily select the desired mode by TTL logic level control signals.
| VT01 | RM-VT01-A | Six-lead SOT-23 Plastic | 1 cGy (1 rad) to 1 kGy (100 krad) | 2.9 x 2.8 x 1.1 |
| VT02 | RM-VT02-A | Eight-lead Ceramic Side Braze | 1 cGy (1 rad) to 1 kGy (100 krad) | 10.3 x 7.9 x 3.05 |
| VT03 | RM-VT03-A | Six-lead SOT-23 Plastic | 3 mGy (0.3 rad) to 10 Gy (1 krad) | 2.9 x 2.8 x 1.1 |
| VT04 | RM-VT04-A | Eight-lead Ceramic Side Braze | 3 mGy (0.3 rad) to 10 Gy (1 krad) | 10.3 x 7.9 x 7.4 |
| VT05 | N/A | Six-lead SOT-23 Plastic | 1 Gy (100 rad) to 10 kGy (1 Mrad) | 2.9 x 2.8 x 1.1 |
| VT06 | N/A | Eight-lead Ceramic Side Braze | 1 Gy (100 rad) to 10 kGy (1 Mrad) | 10.3 x 7.9 x 7.4 |
| RADFET Digital Readout Module | ||||
| VT-DRM(S) | N/A | N/A | TID > 15 krad (Si) | |
| RADFET Reader | ||||
| RADFET Reader Pro | N/A | N/A | 1cGy (1 rad) to 10 kGy (1 Mrad) | |
If you don’t see a product that will measure the dose you require, please contact us to discuss your specific needs.
Doses 1 cGy (1 rad) to 1 kGy (100 krad)
Varadis RADFET VT01
400 nm RADFET in Six Lead SOT-23 Plastic Package
For doses between 1 cGy (1 rad) and 1 kGy (100 krad)
The critical region of the RADFET is its gate oxide. Through generation and trapping of radiation-induced charges in the gate oxide, radiation exposure changes the output voltage of the RADFET and this change is related to the radiation dose. The RADFET response is non-linear and a pre-recorded calibration curve is used to read the dose. The read-out is done by forcing a DC current (in the range of 10s of μA) into the Varadis RADFET VT01 and measuring the DC voltage (in the range of 0.5 to 8 Volts).
Important Information: The VT01 RADFET has a large dynamic range, from 1 cGy (1 rad) to 1 kGy (100 krad). To fully understand the capabilities and limitations of this product, please review the data sheet.
Varadis RADFET Module RM-VT01-A
Using 400 nm RADFET in Six Lead SOT-23 Plastic Package
For doses between 1 cGy (1 rad) and 1 kGy (100 krad)
RM-VT01-A is specially designed for and optimized around Varadis VT01 RADFET, with current source individually adjusted for each part to minimize RADFET threshold voltage drift due to temperature.
Varadis RADFET VT02
400 nm RADFET in Eight Lead Ceramic Side Braze Package
For doses between 1 cGy (1 rad) and 1 kGy (100 krad)
The VT02 is slightly larger than the plastic version. The critical region of the RADFET is its gate oxide. Through generation and trapping of radiation-induced charges in the gate oxide, radiation exposure changes the output voltage of the RADFET and this change is related to the radiation dose. The RADFET response is non-linear and a pre-recorded calibration curve is used to read the dose. The read-out is done by forcing a DC current (in the range of 10s of μA) into the Varadis RADFET VT02 and measuring the DC voltage (in the range of 0.5 to 8 Volts).
The VT02 is used by a number of space agencies across the globe, including ESA (European Space Agency), NASA (National Aeronautics and Space Administration) and JAXA (Japan Aerospace Exploration Agency).
Important Information: The VT02 RADFET has a large dynamic range, from 1 cGy (1 rad) to 1 kGy (100 krad). To fully understand the capabilities and limitations of this product, please review the data sheet.
Varadis RADFET Module RM-VT02-A
Using 400 nm RADFET in Eight Lead Ceramic Side Braze Package
For doses between 1 cGy (1 rad) and 1 kGy (100 krad)
RM-VT02-A is specially designed for and optimized around Varadis VT02 RADFET, with current source individually adjusted for each part to minimize RADFET threshold voltage drift due to temperature.
Doses 3 mGy (0.3 rad) to 10 Gy (1 krad)
Varadis RADFET VT03
1 μm RADFET in Six Lead SOT-23 Plastic Package
For doses between 3 mGy (0.3 rad) and 10 Gy (1 krad)
The critical region of the RADFET is its gate oxide. Through generation and trapping of radiation-induced charges in the gate oxide, radiation exposure changes the output voltage of the RADFET and this change is related to the radiation dose. The RADFET response is non-linear and a pre-recorded calibration curve is used to read the dose. The read-out is done by forcing a DC current (in the range of 10s of μA) into the Varadis RADFET VT03 and measuring the DC voltage (in the range of 5 to 9 Volts).
Varadis RADFET Module RM-VT03-A
Using 1 μm RADFET in Six Lead SOT-23 Plastic Package
For doses between 3 mGy (0.3 rad) and 10 Gy (1 krad)
RM-VT03-A is specially designed for and optimized around Varadis VT03 RADFET, with current source individually adjusted for each part to minimize RADFET threshold voltage drift due to temperature.
Varadis RADFET VT04
1 μm RADFET in Eight Lead Ceramic Side Braze Package
For doses between 3 mGy (0.3 rad) and 10 Gy (1 krad)
The critical region of the RADFET is its gate oxide. Through generation and trapping of radiation-induced charges in the gate oxide, radiation exposure changes the output voltage of the RADFET and this change is related to the radiation dose. The RADFET response is non-linear and a pre-recorded calibration curve is used to read the dose. The read-out is done by forcing a DC current (in the range of 10s of μA) into the Varadis RADFET VT04 and measuring the DC voltage (in the range of 5 to 9 Volts).
Varadis RADFET Module RM-VT04-A
Using 1 μm RADFET in Eight Lead Ceramic Side Braze Package
For doses between 3 mGy (0.3 rad) and 10 Gy (1 krad)
RM-VT04-A is specially designed for and optimized around Varadis VT04 RADFET, with current source individually adjusted for each part to minimize RADFET threshold voltage drift due to temperature.
Doses 1 Gy (100 rad) to 10 kGy (1 Mrad)
Varadis RADFET VT05
100 nm RADFET in Six Lead SOT-23 Plastic Package
For doses between 1 Gy (100 rad) and 10 kGy (1 Mrad)
The critical region of the RADFET is its gate oxide. Through generation and trapping of radiation-induced charges in the gate oxide, radiation exposure changes the output voltage of the RADFET and this change is related to the radiation dose. The RADFET response is non-linear and a pre-recorded calibration curve is used to read the dose. The read-out is done by forcing a DC current (in the range of 10s of μA) into the Varadis RADFET VT05 and measuring the DC voltage (in the range of 2.1 to 3.5 Volts).
Important Information: The VT05 RADFET has a large dynamic range, from 1 Gy (100 rad) to 10 kGy (1 Mrad). To fully understand the capabilities and limitations of this product, please review the data sheet.
Varadis RADFET VT06
100 nm RADFET in Eight Lead Ceramic Side Braze Package
For doses between 1 Gy (100 rad) and 10 kGy (1 Mrad)
The critical region of the RADFET is its gate oxide. Through generation and trapping of radiation-induced charges in the gate oxide, radiation exposure changes the output voltage of the RADFET and this change is related to the radiation dose. The RADFET response is non-linear and a pre-recorded calibration curve is used to read the dose. The read-out is done by forcing a DC current (in the range of 10s of μA) into the Varadis RADFET VT06 and measuring the DC voltage (in the range of 2.1 to 3.5 Volts).
Important Information: The VT06 RADFET has a large dynamic range, from 1 Gy (100 rad) to 10 kGy (1 Mrad). To fully understand the capabilities and limitations of this product, please review the data sheet.
RADFET DIGITAL READOUT MODULE
RADFET Digital Readout Module
Available Q1 2025
Designed in partnership with the European Space Agency (ESA), VT-DRM(S) is a total ionizing dose (TID) measuring module aimed at providing an optimized RADFET read-out for various RADFET technologies. The VT-DRM(S) utilizes 100 nm and 400 nm RADFETs in various sense modes, covering both read-out and irradiation (sense) mode.
The module outputs a digitized threshold voltage, which is directly related to accumulated radiation dose. Designed to compensate for threshold voltage drift due to temperature, VT-DRM(S) provides a stable readout over a large temperature span. VT-DRM(S) can be easily integrated with the host. VT-DRM(S) communicates with the host via standard SPI protocol or isoSPI.
RADFET OUTPUT VOLTAGE MEASUREMENT
RADFET Reader Pro
For measuring the RADFET output voltage
The RADFET Reader PRO is a hand-held, battery-operated dosimetry instrument designed for measuring the output voltage of Varadis RADFETs.
Built on a novel technology currently used in space applications, the RADFET Reader PRO offers the convenience and cost benefits of passive systems but with the added value of active dosimetry and the functionality of more expensive, bulkier devices.
Compatible with the following Varadis products:
- Varadis 400 nm RADFET
- Varadis 100 nm RADFET
- Varadis 1 μm RADFET