Welcome
This issue of Vicor’s Mil-Insight newsletter launches a new, advanced, DC-DC power platform, and presents an overview of MIL-STD-461. It also reveals a challenging naval design which was solved using multiple Vicor modules and illustrates how Vicor’s EMI filters are being used in multi-mode, multi-band radios for tactical vehicles. We hope you enjoy reading Military Insight and that you will email the editor with your comments and suggestions on .
Andy Gales
VP, International Sales
Vicor / Product News
New VI BRICK™ advanced DC-DC power platform
By integrating V•I Chip™ technology into traditional brick packages, the new VI BRICK™ modular DC-DC power platform delivers significantly increased power capability and design flexibility. The family’s robust, low-profile brick packages facilitate both thermal management and through-hole assembly.
The 45 modules within the VI BRICK™ family are optimised for a range of DC-DC configurations: Intermediate Bus Architecture or point-of-load (POL) designs that require multiple output voltages; flexible DC-DC regulation and transformation using Factorized Power™; and 48V DC-DC conversion using advanced Sine Amplitude Converter™ technology.
With a fast transient response, VI BRICK™ modules also minimise the need for bulk capacitance storage near the load, which reduces both space and cost.
Intermediate Bus Architecture or point-of-load (POL)
VI BRICK BCM™ modules can be used to provide an isolated intermediate bus to power multiple non-isolated point-of-load (POL) converters, or as an independent power source. Yielding power density of up to 390 W/in³, BCM™ modules are available with input voltages of 48 Vdc, 350 Vdc or 380 Vdc, and output voltages of 1.5 to 48 Vdc. A typical application would be powering individual cards or blades directly from the HV distribution bus, in a high-power, high-efficiency data centre.
Flexible DC-DC conversion with Factorized Power™ technology
VI BRICK PRM™ and VTM™ modules are a flexible and scalable option for DC-DC power conversion, incorporating the advantages of advanced Factorized Power™ technology. These advantages include high power density and efficiency, low-noise operation, and extremely fast transient response. VI BRICK PRM™ and VTM™ modules support a number of design configurations including multiple outputs, high-power arrays, high-current/low voltage, and high voltage, as well as isolated regulation and transformation to simplify thermal management and board layout.
48 V DC-DC conversion with Sine Amplitude Converter™ technology
VI BRICK 48 V DC-DC converters combine leading-edge Sine Amplitude Converter™ technology and advanced CIM processes in a familiar, easy-to-use package. They deliver high power density, superior transient response, and improved thermal management. Their high-speed, 3.5 MHz, zero-current switching (ZCA) and zero-voltage switching (ZVS) design enables efficient and low-noise operation throughout the operating range. Thirteen different models are available with isolated outputs ranging from 1 to 48 Vdc.
The VI BRICK PRM, VTM, and BCM modules have a compact footprint of 2.08 in², (1.91 X 1.09 inches) and a low profile of 0.37 inches, whilst the VI BRICK DC-DC converter modules are 2.19 X 1.91 X 0.37 inches.
For more VI BRICK product information…
top »New V28 Maxi Series Family of DC-DC Converters
Vicor
has added a V28 series Maxi module to its range of DC-DC converters. With
its wide input range of 10 to 36 V, this module family is targeted at applications
operating from 12 V or 24 V inputs, typical for battery systems in vehicles.
The low-noise ZCS topology greatly reduces the design effort and filtering costs required for power converters to meet conducted emissions requirements. In conjunction with the new 10-36 Vdc input range, these products facilitate the power design for many defence-related vehicle and man-portable applications.
The new V28 Maxi models offer 8 different output voltages ranging from 3.3 V to 48 V with a maximum power of 200 W, four different environmental grades and three baseplate mounting options. The modules, which are optionally available in RoHS compliant models, are a compact 117 x 56 x 12.7 mm in size.
Click here for a copy of the datasheet...
top »New 150-Volt Input Series of DC-DC Converters
Vicor
has introduced a new 150 V input series consisting of 24 base models. The
modules — which incorporate Vicor’s patented low-noise Zero-Current
and Zero-Voltage Switching (ZCS/ZVS) — are ideal for both aerospace
and naval applications.
These new products simplify the AC front end design for applications that
run solely off 100 or 115 V mains because the converter input range matches
the output of a simple rectified front end. Additionally, the low-noise
ZCS/ZVS greatly reduces the design effort and filtering costs required for
power converters to meet agency conducted emissions requirements.
The 24 new models of the 150 V input series include eight standard output
voltages (3.3, 5, 12, 15, 24, 28, 36, 48) in combination with three different
package sizes (quarter brick, half brick, full brick) with output power
ranging from 75 W up to 500 W, depending on the model. The converters operate
from 150 V nominal input, with an input range of 100 V to 200 V and efficiencies
ranging up to 90%. These models are available in five different environmental
grades, with six different pin options and three baseplate options. They
can be also be configured in any combination using Vicor PowerBench™
tools which allow a customer to configure an infinite array of custom module
designs on-line, and verify them in real time.
The modules, which are optionally available in RoHS-compliant models, have a height above board of just 10.9 mm. The footprint for the Maxi is 117 x 56 x 12.7 mm; the Mini is 57.9 x 55.9 x 12.7 mm; and the Micro is 57.9 x 36.8 x 12.7 mm.
Datasheets are available to download:
top »Technical Tip
An Overview of MIL-STD-461
MIL-STD-461E is a comprehensive document addressing Conducted Emissions,
Conducted Susceptibility, Radiated Emissions, and Radiated Susceptibility.
Emission refers to the noise a device generates as it impacts the source
to which it is connected. Susceptibility is the vulnerability of a system
to incoming noise.
Table 1 shows the requirements for each substandard; and Table 2 illustrates the sections related to each of these and the applicability based upon installed platform. As can be observed from Table 2, not all sections are universally required. Hence, most power conversion suppliers focus on achieving compliance to the subset where all installations are affected and in particular to the conducted sections rather than the radiated. These standards are CE102, CS101, CS114, and CS116. Frequently, manufacturers will also reference CE101, as the switching frequency of most DC-DC converters are well beyond the frequency band of interest. Conducted emission and susceptibility requirements are quoted (and not radiated requirements) because radiated sections are significantly dependent upon the physical layout, external output circuitry and enclosure in which the power supply resides. A valid filter design and good PCB layout mean conducted requirements are easily met.
There is not much difference between revision E and the earlier revision D; in fact, of sections CE101, CE102, CS101, CS114, and CS116 only CS101 and CS114 are different. The extent of the differences are:
| CS101 | No change up to 5 kHz; above 5 kHz: |
| 461D: Required level drops 20 dB / decade to 50 kHz | |
| 461E: Required level drops 20 dB / decade to 150 kHz | |
| CS114 | No change up to 30 MHz; above 30 MHz: |
| 461D: Required level drops 10 dB / decade to 400 MHz | |
| 461E: Required level drops 10 dB / decade to 200 MHz |
Basics of EMI
EMI measurement are separated into two parts:
- Conducted
- Radiated
Conducted measurements are measurements of either voltages or currents flowing in the leads of the device under test (as dictated by the standard). Common mode conducted noise current is the unidirectional (in phase) component in both the positive and negative inputs to the module. This current circulates from the converter via the power input leads to the DC source and returns to the converter via the output lead connections. This represents a potentially large loop cross-sectional area that, if not effectively controlled, can generate magnetic fields. Common mode noise is a function of the dv/dt across the main switch in the converter and the effective input to output capacitance of the converter. Differential mode conducted noise current is the component of current, at the input power terminal, which is opposite in direction or phase with respect to each other.
E-Field radiated emissions are due to conducted currents through a suitable antenna such as the power leads of the device under test. If we can greatly reduce the conducted emissions then we will reduce the radiated emissions as well. The enclosure of the device under test, lead geometry, and other devices running within the device under test will affect the emissions. Radiated emissions due to B-Fields are best addressed by shielding with a suitable material and proper layout.
Vicor Products Compatible with MIL-STD-461
Vicor offers a variety of products that enable a design engineer to meet MIL-STD-461, as shown below.
MIL-STD-461: Vicor Product Selection |
|||
| Vicor Product | MIL-STD-461C | MIL-STD-461D | MIL-STD-461E |
| MI-A22-xx MI-A66-xx MI-J2x-xx (with MI-A22-xx) MI-J6x-xx (with MI-A66-xx) MI-22x-xx (with MI-A22-xx) MI-26x-xx (with MI-A66-xx) |
CD01, CE03, CE07, CS01, CS02, CS06 | CE101, CE102, CS101, CS114, CS115, CS116 | CE101, CE102, CS101, CS114, CS115, CS116 |
| M-FIAM3 M-FIAM5B M-FIAM7 24 Vin Maxi, Mini, Micro (with M-FIAM5B) 300 Vin Maxi, Mini, Micro (with M-FIAM3) 28 Vin V•I Chip (with M-FIAM7) |
CE101, CE102, CS101, CS114, CS115, CS116 | ||
| MI-AIM-xx MI-J7x-xx (with MI-AIM-xx) MI-27x-xx (with MI-AIM-xx) |
CE102 | CE102 | |
| MI-ComPAC
28 Vdc MI-ComPAC 270 Vdc |
CD01, CE03, CE07, CS01, CS02, CS06 | CE101, CE102, CS101, CS114, CS116 | CE101, CE102, CS101, CS114,
CS116 CE101, CE102, CS101, CS114, CS115, CS116 |
| MIL-VIPAC 28 Vdc | CE101, CE102, CS101, CS114, CS115, CS116 | ||
For more information on how to use Vicor’s V•I Chip products to meet MIL-STD-461 you can download the complete white paper MIL EMI and Transient Solutions
top »Novel Applications
Picor EMI filters used in military vehicle radios
The reliability and compact packages of Vicor Picor modules were key considerations for a Vicor customer in Turkey. The Picor modules are being used to achieve low EMI by reducing switching noise at the converter input, and to reduce the ripple currents at the output of the converter, in multi-band, multi-mode radios designed for use in tactical military vehicles.
The QPI family of active EMI filters provides conducted common-mode (CM) and differential-mode (DM) attenuation from 150 kHz to 30 MHz in the CISPR22 range. The proprietary active filtering circuit provides superior attenuation at low frequencies to comply with EN Class B limits, including PICMG® 3.0 for ATCA boards.
Compared to passive filters, active filtering reduces the volume of the common-mode choke, and allows the use of a low-profile, surface-mount package. This smaller size saves valuable board-space and reduces the height which camn improve airflow in blade applications.
The QPO output ripple attenuator products use proprietary active filtering to reduce power supply output ripple and noise (PARD) over 30 dB from 1 kHz to 500 kHz. QPOs improve transient response, ensure quiet point-of-load regulation and work with most DC-DC converters and switching power supplies. Output regulation is maintained by using remote sensing or the trimmed input of the power supply. Active filtering can also effectively reduce load capacitance by a factor of 10 whilst maintaining comparable transient performance.
For Picor product information...
top »Complex Naval range-finder integrates 27 Vicor modules
Designed for Naval applications by a major defence supplier, the electro-optical range-finder comprises infrared and daylight cameras and a laser to allow the user to accurately determine the range for naval weapons systems. The complexity of the design required multiple outputs and power levels, whilst the Naval application added the need to meet stringent reliability and environmental standards.
Each range-finder integrates 27 individual Vicor modules. The Micro, Mini and Maxi series of DC-DC converters provides input voltages ranging from 10 to 425 Vdc, with output ranges from 2 to 54 Vdc. The Vicor M-FIAM3 input filter ensures that the range-finder complies with MIL-STD-461E for EMI, which was critical in this application. Crucially, the converters and the input filter also meet key specifications in the MIL-STD-810 environmental standard to ensure reliable operation in high-salt, Naval environments.
The range-finder is currently undergoing rigorous testing by the customer.
For more information on the Maxi, Mini, and Micro family of DC-DC converters
visit:
http://www.vicorpower.com/products/military/mmm/
For more information on the M-FIAM family of input
filters visit:
http://www.vicorpower.com/products/military/mfiam/
New on the web / New from Vicor
New catalogue features VI BRICK and new WebExpressCodes
The
new Vicor product catalogue includes the latest VI BRICK DC-DC converters
as well as unique WebExpressCodes for fast access to full product information
on www.vicorpower.com.
The catalogue is available now by registering your details on the link below.
Each product in the new Vicor catalogue includes a unique WebExpressCode which provides direct access to information-rich product pages on www.vicoreurope.com. For fast and easy access to full details, such as product description, operating specifications, datasheets, outline drawings, and configuration tools, simply enter the Web ExpressCode in the search box on the www.vicoreurope.com homepage.
Vicor develops new products all the time, and these could provide the solution to your latest power design challenge. To review the latest products, visit www.vicorpower.com and click on the ‘What’s New’ link for an overview, and links to detailed information on all new Vicor products, as they are released.
top »
V•I Chip™ application notes
A library of V•I Chip™ application notes helps designers to achieve smaller, higher-performance and more cost-effective power systems using Vicor’s latest VI BRICK™ DC-DC power platform.
The Factorized Power Architecture™, enabled by V•I Chip™ technology in the new VI BRICK™ power platform, maximises power system by providing a high degree of system flexibility as well as superior power density, efficiency, transient response, and reliability.
- AN:001 Configuring the Vicor BCM with low power niPOLs
- AN:002 PRM/VTM parallel operation
- AN:003 Powering multiple VTMs with a single PRM
- AN:005 FPA printed-circuit board layout guidelines
- AN:006 A filter solution for the BCM
- AN:007 Using VTMs as 26 – 55 V input bus converters
- AN:008 V•I Chip Bus Converter Module (BCM) thermal management
- AN:009 V•I Chip soldering recommendations
- AN:016 Using BCM™ bus converters in high-power arrays
- AN:017 RoHS-compliant through-hole V•I Chip soldering recommendations
- AN:022 MIL EMI and transient solutions