There are three levels of customization: a modified standard product, which is the simplest option; a semi-custom design; and a full custom design.
New DC/DC Converters Simplify Custom Projects
Jun 16, 2023
RECOM offers a portfolio of over 30,000 off-the-shelf DC/DC converters that can meet the vast majority of requirements. Even so, a particular application may call for something more, from a slight change in specifications to a one-of-a-kind custom design.
Table of contents
Modified Standard Products
A modified standard product starts with an off-the-shelf part and changes it in some small way to optimize voltage regulation for a perfect solution. Examples of such modifications include:
Such requests are easy to implement in RECOM’s production lines and qualify as modified standard products. In many cases, the existing certifications for safety and EMC remain valid, saving significant costs and time. Furthermore, RECOM has manufactured many ‘modified standards’ in the past, so a solution might already be available for a particular set of requirements, even if it is not listed in the datasheet.
- A small change to the output voltage—for example, 5.1V instead of 5.0V
- A pinout change—for example, removing a pin so the part fits into an existing board
- A change of encapsulation material—for example, epoxy instead of silicone
- A longer or shorter pin length, or pins that are bent at 90°
Such requests are easy to implement in RECOM’s production lines and qualify as modified standard products. In many cases, the existing certifications for safety and EMC remain valid, saving significant costs and time. Furthermore, RECOM has manufactured many ‘modified standards’ in the past, so a solution might already be available for a particular set of requirements, even if it is not listed in the datasheet.
Semi-Custom Designs
A semi-custom design is the next stage of customization. The boundary between a semi-custom and a modified standard power converter is not always obvious, so a useful definition is whether the change will require a safety re-certification. Modifications that influence safety-critical components or separations—such as the transformer construction, choice of optocoupler or Y-capacitor, or creepage or clearance distances—will almost certainly require a new certification process.
Often, a customer specification can be met using an existing ‘platform’ design that has the advantage of proven performance and reliability in the field. This is a more economical approach than a full custom design, with simplified product safety assurance and EMC certification, reducing risk and accelerating time to market. Using existing in-house stock components, tooling, and manufacturing processes results in a cost-effective product.
Often, a customer specification can be met using an existing ‘platform’ design that has the advantage of proven performance and reliability in the field. This is a more economical approach than a full custom design, with simplified product safety assurance and EMC certification, reducing risk and accelerating time to market. Using existing in-house stock components, tooling, and manufacturing processes results in a cost-effective product.
Full Custom Power Converters
A full custom power converter is specifically designed for the required application, rather than being based on an existing product. Instead of tweaking a standard product, the design team typically begins with proven and tested building blocks and existing production infrastructure to develop a unique solution.
New Standard Products Designed for Customization
The DC/DC converter market is continually evolving, and RECOM is always improving its product line to meet new challenges. RECOM’s isolated converters are undergoing an improvement program, introducing redesigned versions of some of our most popular power modules. These performance enhancements result from advanced circuits and manufacturing techniques. New planar-style transformers can be automatically placed, and flexible automation keeps costs down—even reducing costs for some new products in volume.
The regulated designs now use two integrated circuits (ICs), one each on the primary and secondary side of the transformer. The primary-side IC is a wide-input, push-pull transformer driver. The output side has a secondary synchronous buck stage for tight regulation over the full load range. Synchronous rectification improves efficiency by replacing lossy diodes with FETs that switch on and off under the direction of the controller.
The new models are easily distinguished by the appearance of a "K" in the part number. For example, the 3W SIP8 RS3K-Z series is an enhancement to the RSE series. The -K version has a 4:1 input range and 3kV agency-rated ‘basic’ isolation compared with 2:1 input and 3kV ‘functional’ isolation for the -E series. The RS3K-Z also features a wider operating temperature range without derating to +80°C, higher efficiency, and lower isolation capacitance.
The RSK-RUW series isolated DC/DC 2W converter features an 8:1 input voltage range of 4.5-36 VDC. The series includes ON/OFF control for added convenience, continuous short circuit protection, and an under-voltage lockout (UVLO) for added safety. The RSK-RUW offers basic grade isolation of 3kVDC/1min and an industrial operating temperature range of -40°C to 85°C, without derating, making it ideal for demanding industrial environments.
The regulated designs now use two integrated circuits (ICs), one each on the primary and secondary side of the transformer. The primary-side IC is a wide-input, push-pull transformer driver. The output side has a secondary synchronous buck stage for tight regulation over the full load range. Synchronous rectification improves efficiency by replacing lossy diodes with FETs that switch on and off under the direction of the controller.
The new models are easily distinguished by the appearance of a "K" in the part number. For example, the 3W SIP8 RS3K-Z series is an enhancement to the RSE series. The -K version has a 4:1 input range and 3kV agency-rated ‘basic’ isolation compared with 2:1 input and 3kV ‘functional’ isolation for the -E series. The RS3K-Z also features a wider operating temperature range without derating to +80°C, higher efficiency, and lower isolation capacitance.
The RSK-RUW series isolated DC/DC 2W converter features an 8:1 input voltage range of 4.5-36 VDC. The series includes ON/OFF control for added convenience, continuous short circuit protection, and an under-voltage lockout (UVLO) for added safety. The RSK-RUW offers basic grade isolation of 3kVDC/1min and an industrial operating temperature range of -40°C to 85°C, without derating, making it ideal for demanding industrial environments.
Customization Benefits and Streamlined Design Cycles
An added benefit of this new architecture is that it simplifies the design of custom DC/DC modifications with shorter design cycles and reduced testing requirements. In some cases, the new products eliminate the need for a custom design. The improved specifications enable a standard product to meet application requirements that previously required customization. For example, the RSK-RUW’s increased input voltage range of 8:1 broadens the range of applications that can use the standard product.
Even if a custom design is needed, the new architectures allow the designer to opt for a modified standard product rather than a semi-custom or full-custom solution. Many of the new converters have upgraded isolation from functional grade to basic grade with IEC/EN62368-1 certification. This may shorten the design cycle by eliminating the lengthy recertification process associated with an isolated transformer change. The new designs also accommodate output voltage changes without requiring transformer winding modifications—only two internal resistors need adjustment.
The new DC/DC converters mentioned are only the first in a series of new designs to be released in the coming months. For more information, contact RECOM.
Even if a custom design is needed, the new architectures allow the designer to opt for a modified standard product rather than a semi-custom or full-custom solution. Many of the new converters have upgraded isolation from functional grade to basic grade with IEC/EN62368-1 certification. This may shorten the design cycle by eliminating the lengthy recertification process associated with an isolated transformer change. The new designs also accommodate output voltage changes without requiring transformer winding modifications—only two internal resistors need adjustment.
The new DC/DC converters mentioned are only the first in a series of new designs to be released in the coming months. For more information, contact RECOM.
Applications
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RS3K
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RSE
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RSE-Z
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RSK-RUW
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