Tuesday, June 30, 2015

200°C High Temperature, High Voltage, 5kV Diode - SMF6533HT

SMF6533HT 5kV, 200°C,  Diode

Introducing VMI's latest addition to the 200°C, high temperature, high voltage diode family.
The SMF6533HT (HT for "High Temperature) is rated at 200°C.  It will block 5kV in the reverse direction and conduct 50mA in the forward direction.  Reverse Recovery Time (Trr) is 70ns or less.

Physical Dimensions

The SMF6533HT is the same size as the SMF6531HT, and less than 1/4" in length.  That means you can pack a lot of voltage in a very small package.  For precise dimensions and recommended pad layout, see below.
Physical Dimenions of the SMF6533HT High Temp, High Voltage Diode

Recommended Pay Layout

The dimensions are given in inches, with mm in parentheses. 
Pad layout recommendations for SMF6531HT High Temp Diode
SMF6533HT Pad Layout

Data Sheet

For more information on the 200°C, 5kV, 50mA, 70ns, SMF6533HT diode, download the data sheet.  or contact VMI.

Thursday, June 25, 2015

New 200°C High Temp, High Voltage Diode - SMF6531HT

SMF6531HT 3kV, 200°C,  Diode

Introducing VMI's latest addition to the 200°C, high temperature, high voltage diode family.
The SMF6531HT (HT for "High Temperature) is rated at 200°C.  It will block 3kV in the reverse direction and conduct 100mA in the forward direction.  Reverse Recovery Time (Trr) is 70ns or less.

Physical Dimensions

The SMF6531HT is less than 1/4" in length, which means you conserve board space.  For precise dimensions and recommended pad layout, see below.

SMF6531HT Physical Dimensions
Physical Dimenions of the SMF6531HT High Temp, High Voltage Diode

Recommended Pay Layout

The dimensions are given in inches, with mm in parentheses. 
Pad layout recommendations for SMF6531HT High Temp Diode
SMF6531HT Pad Layout

Data Sheet
For more information on the 200°C, 3kV, 100mA, 70ns, SMF6531HT diode, download the data sheet.  or contact VMI.

Tuesday, June 23, 2015

High Voltage, Voltage Multipliers

High voltage multipliers are used in many applications including image enhancement, instrumentation, CRT displays (remember them?), high voltage power supplies, and more.

High Voltage

"High Voltage" for a VMI voltage multiplier is anything with a voltage output between 1kV and 120kV.  Output currents range from nA to ten's of Amps, and depends largely on size constraints and output voltage.   

Custom Multiplier Designs

Most of VMI's multipliers are custom designs.  When a customer first contacts us with their requirements, we review the information, and usually give them a call back with questions.  VMI understands that not all parameters are known up-front, and not all of them are important.  For instance, some applications run multipliers in large oil tanks with ample space.  Size limitations are less critical than, say, a multiplier going on a satellite or space probe.

We ask questions because we want to meet the customer's needs, with the understanding that the information may change, or it may be unknown, or to-be-determined.    

Conflicting Design Parameters

Sometimes it isn't possible to meet all the requirements.  The customer may have to prioritize which characteristic is more important. 

For example, you need a low ripple of 100mV, but you also need it to be very, very, small.  In fact, maybe your desired dimensions are not large enough to accommodate the capacitors needed to meet the 100mV ripple.  In that situation, you get to choose between low ripple voltage or small size.  There are options available , and VMI will present them to you.  For instance, if size is the number one priority, then perhaps an external filter could be used.  Or, if the part will be operating at room temperature, then maybe a capacitor with a high dielectric at room temperature could be used.  

Multiple Iterations Are The Norm

Often the first go-round generates more questions, and more options, and because VMI engineers are easily accessible, it makes the design and development process smooth. 

Cut-Away View of a Typical 6-stage Voltage Multiplier

Contact Us

Feel free to contact VMI with your voltage multiplier requirements.  If we can't assist you, we'll help you find someone who can.

Thursday, June 18, 2015

High Voltage Multipliers

VMI makes several standard multipliers, namely the Hybrid Multipliers found here.  They typically

Surface Mount Multipliers
have 3kV to 14kV outputs, and low current - 50uA to 200uA.  They are small, reliable, high voltage, low current, surface mount multipliers.  And they're standard products.

Custom Designed High Voltage Multipliers

But what happens if they are not exactly what you need?  Well, it's VMI to the rescue!  VMI is one of the few remaining companies who design custom multipliers.  We'll ask you a few questions and take it from there.

If you don't know the answer to the questions we ask, we'll help you answer them.  It's really that simple.  Of course, the more information you have going in to a new design, the better, but we understand that not parameters are clearly defined in the beginning, or they may change.  That's okay too.  We're flexible.

Design Questions

Below is a sampling of the kinds of questions you might be asked during the design phase to better help us understand your particular needs and application.  

Here goes - 

  •  How many stages do you want in your multiplier?
  • What size/shape is acceptable for your multiplier?
  • What is your input voltage?
  • What is your input frequency?
  • Do you have ripple requirements? Regulation requirements?
  • Do you want the multiplier to be surface mount?
  • Any information you can provide on the application?
  • Environmental factors (temperature, altitude, moisture, etc.)?
  • Target price?
  • Quantity (annual, prototype, etc.)?

Based on the information you provide, we can help you get exactly the multiplier you need for your application.

It's that easy!

JANTX Level Processing

Voltage Multipliers Inc. continues to manufacture several military-grade, JANTX, and JANTXV high voltage diodes in accordance with Mil-Prf-19500.

JANTXV Processing Capability

What you may not know is that VMI has the capability to process non-QPL diodes to the JANTX or JANTXV levels.  We can't certify them as JANTX/JANTXV, but they have been processed as if they were JANTX/JANTXV diodes.  The same tests, conditions, sampling plans, and read-and-record data, still apply.  

1N6525U and 1N6517US High Voltage Diodes

QPL Surface Mount Diodes
For example, the 1N6525U is a 5kV, 150mA, 70ns, surface-mount diode, and is basically a commercial device.  It can be processed to the JANTX or JANTXV level, but cannot be labeled as such.

QPL and Non-QPL Part Number Designations

In comparision, VMI is qualified to manufacture (QPL'ed) the 1N6517US (note the "S" on the end of the part number).  The part number is specified in the governing slash sheet (Mil-Prf-19500), and includes an "S" on the end.  The 1N6517US is a 5kV, 2.0A, 70ns surface-mount diode.  It can be processed to the JANTX or JANTXV level.  It's full part number would be JANTX1N6517US or JANTXV1N6517US, depending on the level of processing needed.    

Coming Soon!

VMI is pursuing qualification of the formed leaded devices and the SXF/SMF devices, so check our list of QPL devices often.  

Tuesday, June 16, 2015

To Be, or Not to Be Digital! THAT is the Question! Part 3

The ViPS-40 has several advantages over standard analog control power suppliers.  

In our previous post, we outlined several challenges to integrating the tube power supply into an X-ray system. 

During the design and development stages, tube characteristics are often in flux, which means the power supply outputs are subject to change.  

When power supply outputs change, so can physical or electrical characteristics - either of which can send a designer back to the drawing board.  The ViPS40 can prevent having to start from scratch with it's adjustable outputs, for just such an occasion.  

You're not locked into tube characteristics because you have room to move.  Sweet!    

ViPS40 Features

ViPS40 PC User InterfaceTube Tracking

A unique feature of the ViPS40 not available in analog controlled power supplies is the ability to record the life-time of the x-ray tube, and to track and display the tube ‘on’ time.

Programmable Outputs

The ViPS40 power supply can be easily reprogrammed to support different outputs, putting you in charge.  Move with ease from application to application with no software changes.  Just enter the desired voltage outputs, current outputs, control inputs, and operating limits through a user-friendly PC-interface.  The ViPS40 puts you in control.

Real-time Monitoring

Operating conditions like temperature, output voltage, and output current levels can be constantly monitored.  You can also adjust the voltage and current levels of power supply through the interface.  The ability to monitor real-time conditions gives the design engineer information and the ability to maximize system run-time, to determine likely failure, minimize down-time, and provide valuable data to a Repair Technician. 

Advantages of the ViPS40

Lower Component Count

The lower component count keeps costs down without compromising on regulation and output control.  

Integrated Protection and Auxiliary Functions

Protection functions such as over-voltage, over-current, and over-temperature, are easily integrated.  Auxiliary functions like fan control and data logging are available.  The ViPS40 is capable of storing power supply voltage and current levels, and filament voltage levels.

Firmware Changes Not Required

No changes to firmware means faster system integration time, and lower integration costs.

Yes, high voltage design can be exciting and fun! 

Contact VMI for more information!

Thursday, June 11, 2015

To Be, or Not to Be Digital! THAT is the Question! Part 2

In the first post we discussed high voltage x-ray tubes and system, and interesting things about high voltage designs.

In this post we'll discuss the challenges to integrating high voltage power supplies into x-ray systems and introduce the ViPS40, 40kV high voltage power supply.

Challenges to Integrating High Voltage Power Supplies

Power supply integration is more difficult when tube characteristics are in flux, as is often the case during the design and development stages.  Further, some power supplies have fixed inputs or outputs making them less adaptable to different tube parameters, and requiring hard ware changes, which slows down the development process. 
From a manufacturing perspective, the more applications one power supply can be used in, the better for inventory levels and component counts.  One power supply used in several applications may increase the volume, triggering volume discounts.  This makes it even more attractive.  

To Go Digital, or Not to Go Digital.  THAT is the question!  Or is it?

Good news!  You CAN have it all.  Or at least, the best parts of the digital and analog worlds because digital and analog are no longer mutually exclusive.       
Now there is a high voltage power supply that will help you monitor, power, and control, your x-ray tube - digitally.  

ViPS40 Solution 

The ViPS-40 is one of the first of its kind – a digitally controlled, PC-based, fully programmable 40kV power supply designed specifically for high voltage x-ray applications.
Standard features such as fully programmable output voltage and current set points, and a soft-start function to limit in-rush current, are controlled via the digital control loop.    

In our next post we'll delve deeper into the ViPS49 features, and why it's your high voltage solution.

Tuesday, June 9, 2015

To Be, or Not to Be Digital! THAT is the Question! Part 1

In the first of three posts, we'll look at the advantages and drawbacks of analog and digitally-controlled high
voltage power supplies.

To Go Digital, or Not to Go Digital.  THAT is the question!

 X-ray system designers and power supply engineers have enough headaches deciding between analog or digital controls in low voltage designs. 

Did You Know?

For starters, low voltage designs differ from high voltage designs in that low voltage designs are not usually concerned with corona (that fun thing that happens when trapped gas is repeatedly polarized over time, resulting in insulation degradation and shorts), or unintentional solder peaks that serve as lightning rods for arcs, or board spacing through air or other mediums.    
The use of high voltage increases the complexity of the design and the decision making process because of these special circumstances, making the “analog or digital” decision even more difficult.    

High Voltage X-ray Tubes and Systems

If you’re working with x-ray systems and tubes, you understand how challenging it can be to accurately control the power supply that controls the tube.  Direct output measurements are not always available and sometimes feedback signals are not easily verified.     
Specialized applications coupled with the growing X-ray analysis market mean high voltage power supplies are not just an afterthought, like in the good old days.  X-ray tube power supplies can, and should, play a central role in X-ray system design.  The sooner the power supply can be integrated into the system, the better. 

In our next post, we'll look at the challenges of integrating high voltage power supplies, and what that means to design engineers.