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Here you will find answers to the most frequently asked questions from our world-wide customers and partners. To submit your own question, please email us at

Sales and commercial

Who is Flex Power Modules?

In October 2017, Flex acquired Ericsson Power Modules which was formed in the late 1970s, and since then we have been trading as Flex Power Modules. We are part of the Power cross industry technology group, and we design and manufacture board-mounted DC/DC conversion products for applications within the telecom (including 5G), data center, AI, industrial and railway markets. More details can be found in the About Us section of our website.

How can I keep up to date with news about your products?

We have a dedicated section of our website for new product notifications. You can also sign up for our email Newsletter. We also have a dedicated LinkedIn page where we discuss our latest updates.

How can I get in contact with someone to discuss my needs?

You can reach out to us by completing the Contact Us form. Should you need to send us any documents or files for review, then for Commercial support please email, and for Technical support please email

Where can I purchase your products?

We have a global network of channel partners and representatives who are technically trained to support the design-in of our products and are able to offer supply solutions. Please visit our partner page in order to find the right partner for your region.

What are your current lead times?

Since this changes from time to time based on prevailing market supply conditions, contacting your regional partner is the best way to get current lead times, as well as discussing additional supply options. If you have a specific urgent need for parts, then please contact us at

How do I get samples for evaluation?

Sample requests can be sent to our partners to support new designs. On our partner page you can find a partner for your region.

Where do I find prices for your products?

Please contact our partners for pricing information. On our partner page you can find a partner for your region.

What is the Country of Origin (COO) of your products?

The Country of Origin (manufacturing location) of our products is either China, Taiwan or Malaysia, depending on the particular family. Specific details can be discussed by contacting us at

What is the ECCN classification of your products?

At the time of writing, the Export Control Classification Number (ECCN) of all our products is "EAR99".

What is the six-digit HS code for your devices?

The six-digit HS (Harmonized System) code for our devices is 8504.40. This is the basis of what's needed by importers of our products to further define the specific 10-digit HTS or TARIC code for import to a specific Country.

Can you share your Quality and Environmental certificates?

The certificate for our ISO 9001 Quality Management System can be found HERE.

The certificate for our ISO 14001 Environmental Management System can be found HERE.

The certificate for our ISO 45001 Occupational Health & Safety Management System can be found HERE

What if you don't have what I need listed on your site?

Don't see what you need? We are constantly developing new solutions so please let us know your request by contacting us and we can discuss your specific needs.


How can I get technical support on your products?

We have a global network of partners and representatives technically trained in our products. Please contact our partners. Additionally, you can email your inquiry to, and one of our Application Engineers will respond to your request.

Where do I find life-cycle information about your products?

If you have a question on product life-cycle, please reach out to our partners and representatives or alternatively you can contact us directly. Our representatives can answer questions about the product life-cycle for all the products found on our web pages.

Products that are marked on our site as "Legacy" typically refer to parts that have already had a Product Discontinuation Notice (PDN) issued, and they are in their Last Time Buy (LTB) / End of Life (EOL) period. Products marked as "NRND" are Not Recommended for New Designs, typically as they are coming towards the end of their life, but a PDN may not yet have been issued. We continue to list these products on our website however to support existing customers and projects. The most recent PDNs are listed online under the Resources/Downloads section of the website.

How will I be informed about product/process changes and end of life statements?

When we have a PCN or PDN to issue, these will be shared with our Channel Partners who will feed the information down to affected customers that have been active typically within the previous 3 years or so. The most recent PDNs are also listed online under the Resources/Downloads section of the website.

What is the warranty on your products?

Flex warrants that, during a period of three (3) years from the date of manufacturing of the product, unless another time period is explicitly agreed in the Sales Contract, the product will be free from major defects in material and workmanship, and will meet the agreed technical specification in all major aspects.

How can I arrange an RMA/FAR for your products?

If for any reason you need to return products for failure analysis, this should be done through the originally-sourced channel. If this was via one of our Channel Partners, then you will find their contact information on our partner page. Otherwise, you can contact us directly at to request an RMA.

Where can I find safety certifications for your products?

Many certificates are posted on the associated product pages, but if not available there please contact us at for more information. We will be happy to provide these on request.

Where can I find details about your RoHS and REACH compliance?

Our RoHS statement of compliance can be found HERE, while our REACH statement of compliance can be found HERE

Can you provide a completed Conflict Minerals Reporting Template (CMRT) and Extended Minerals Reporting Template (EMRT)?

Yes we can provide this on request. Please reach out to us at

Do your products contain Persistent, Bioaccumulative, and Toxic (PBT) Chemicals under TSCA Section 6(h)?

All existing and active products within our range of DC/DC Power Modules fulfill the TSCA requirement, and do not contain any of the substances included in it. Our statement to that effect can be found HERE.

Do your devices meet the 62368-1 safety standard?

Yes, as of the 1st November 2020, ALL of our products have been successfully recertified to meet IEC/EN/UL/CSA 62368-1 (Audio/Video, Information and Communication Technology Equipment - Part 1: Safety Requirements), which replaced the IEC/EN/UL/CSA 60950-1 standard from 20th December 2020. Individual certificates are mostly available on the product landing pages, or if not please request them by emailing us at

Do you offer AC/DC products?

At the time of writing we do not offer AC/DC products, and focus all of our efforts on developing the very best DC/DC solutions for your needs.

Do you offer EN50155 compliant DC/DC converters for Railway applications?

Yes we do! We have a wide and growing range of DC/DC converters that meet the requirements of EN50155 which is the global standard in use for electronic equipment used on rolling stock in railway applications. Our products that are specifically targeted at Rail Applications such as PKM-A, PKM-W, PKJ, PKJ-W etc. can be supplied with a Verification of Conformity (VoC) showing externally tested conformance to EN50155, but even industrial products such as PKE, PKE-A, PKU-S etc. are designed to meet the standard. Additional information can be found in this Article, and specific queries can be discussed by contacting us at

Do you offer DC/DC converters for 5G RFPA applications?

Yes we offer a wide range of DC/DC converters suitable for 5G RFPA RRH/RRU designs powering both LDMOS and GaN RF transistor technology. As well as providing solutions to the traditional WW Radio manufacturers, we are also actively working with members of both OpenRAN (Telecom Infra Project) and the O-RAN Alliance, and our RFPA product offering can be seen HERE, with many more devices currently in development, so please contact us if you don't see what you need. Of course, these products are also suitable for other 4G-LTE, 4G, 3G and 2G applications, as well as Microwave fronthaul, midhaul and backhaul radios and Point to Point (PTP) and Point to Multipoint (PTMP) designs.

Do you offer DC/DC converters for Gate Drive applications?

Yes we offer both symmetric and asymmetric dual output devices suitable for Gate Drive applications to power Silicon, IGBT, SiC and GaN designs. Available power levels are from 1-2 W, and isolation voltages of up to 6kV are available. An example of a standard output voltage combination is +15V/-9V for IGBT designs, but more variants are being added to this range all the time, so please contact us to discuss your specific needs in this area.

What type of input filter do I need to reduce conducted noise?

This is dependent on the particular module in question. Our technical specifications for isolated devices typically provide EMI conducted noise plots both with and without additional external filtering, and the filter suggestions provided are to meet Class B conducted noise emissions according to EN55022/EN55032, CISPR22/CISPR32 and FCC part 15J.

Do you offer filter modules for EMC compliance?

We do not offer dedicated EMC filter modules currently, but we do offer Power Interface Modules or PIMs, some of which do contain EMC filtering as well as many other useful features such as OR-ing, Hot Swap, Hold-Up voltage boost and Auxiliary voltage rails. More details of these products can be found by clicking HERE.

Can I connect your products in series?

It may be the case that a particular module cannot deliver the specific voltage required by a particular application.

In these cases, it's good to know that our products can typically be connected in series to produce these alternative voltages.

For example, it’s possible to connect the outputs of two 30V converters in series to produce a 60V rail. It may be necessary to include protection circuitry however to disable one device if the other one turns off for any reason.

Our FAEs can support your designs by contacting us at

Can I connect your products in parallel?

Sometimes, a single module will not provide the required level of current or power needed in a particular application. In these cases, it's often desirable to connect devices in parallel.

Whether or not this is possible with our products is actually device dependent, so please consult the technical specification of the device in question to check if this is advisable.

Some modules include a voltage droop current share mechanism, while others include an active current share scheme. Some devices are not recommended for paralleling at all, or will need external current share control circuitry.

Design Note DN006 goes into more detail about this, or one of our FAEs can also support you by contacting us at

Can I use active trimming on your converters?

The output voltage of many, but not all, of our converters can be trimmed actively using a voltage source. Please consult the specific technical specification for the device in question. Our FAEs can also guide you by contacting us at

What are the different regulation techniques used by your converters?

Typically, an Intermediate Bus Converter, or IBC, can be fully regulated, semi-regulated or unregulated. When selecting suitable devices for your application, consideration needs to be given to the source voltage range and if/how well that is regulated itself, and also to the allowable input voltage ranges of any downstream Point of Load (PoL) or Voltage Regulator Module (VRM) devices, as well as any additional circuitry that may be fed by the output of the IBC directly.

In a fully regulated design, the output voltage is regulated to a defined level (within tolerances and specified line and load regulation ranges) such as 12V, 9V or 5V for example, over the entire line and load ranges.

Semi-regulated devices include those that use Flex Power Modules' "Hybrid Regulated Ratio" (HRR) regulation technique. This effectively regulates the output of the converter tightly above a certain input threshold voltage, but below that level the output is unregulated and will follow the input voltage as it changes. More information on that can be found HERE.

Unregulated devices, also known as Fixed Ratio devices, act effectively as a DC transformer, where the output follows the input according to a defined ratio, typically 4:1, 6:1, 8:1 etc. Read more about that below.

What do the different ratios of 2:1, 4:1 etc. refer to?

These ratios often describe the input voltage range of a converter. As an example, a 2:1 input ratio converter suitable for a 48 V nominal supply would have a voltage range of 36-72 V typically, although this is often extended to 75 V. An equivalent 4:1 converter would have an input range of 18-72/75 V, making it actually suitable for both 48 V and 24 V nominal supplies. Another version of a 4:1 range includes 9-36 V, which would be suitable for both 12 V and 24 V nominal supplies. Our product range now even includes devices such as the PKM-W series for the Railway market with >13:1 input ratios, operating over an input voltage range of 12-160 V.

The term is also now commonly used to refer to the effective transformer ratio between input and output of an unregulated converter. For example, for an unregulated device with a 4:1 "transformer ratio", and an input voltage range of 40-60 V, the output voltage will range from 10-15 V, and so when supplied with a 48V input, the output would be at 12 V.

Can I generate negative voltages with your converters?

Yes when using our isolated DC/DC converters. If you connect the +OUT pin to the system output ground, a negative voltage will be generated on the -OUT pin.

How do I connect the sense lines?

Many DC/DC modules provide sense pins which enable the output to compensate voltage droops due to the copper resistance of the traces of application boards.

Note that the DC/DC converters accurately regulate the voltage between +sense and -sense pins, not the voltage on the output pins. Voltage droops of up to 0.25-0.5V may be compensated if the sense pins are connected to the corresponding terminals of the load.

However, to avoid noise, the sense traces should be properly routed to minimize the area between them, i.e. they should be as short as possible and close to each other.

If not used, the sense pins should be connected directly to the corresponding output pins.

What is the Remote Control pin, and what does Positive and Negative logic mean?

The Remote Control pin (RC, On/Off or CTRL) allows the user to turn the module on and off manually by applying a voltage to that pin, typically via a mecahnical switch or an electronic version such as a MOSFET.

Positive logic means that the module is "active high", and will turn on if a positive voltage is applied to the RC pin, when referenced to the -IN pin (negative input pin).

Negative logic means that the module is "active low", and will turn on if a negative voltage is applied to the RC pin, when referenced to the -IN pin (negative input pin).

How should I accurately measure the Output Ripple?

Please refer to DN022 for detailed information on measuring Output Ripple. Our FAEs can also guide you by contacting us at

Is it possible to adjust the output voltage of your digital converters below the defined minimum voltage?

Our isolated digital DC/DC converters are mostly targeted at providing intermediate bus voltages of around 10-12V, and so the output voltage adjust range given in the Technical Specification is often given as 8-13.2 V, which is what we have verified the devices to during verification and qualification.

It is however possible to adjust the output voltage of our digital intermediate bus converters down to as little as 0 V in theory using the PMBus interface, but in that case the device is considered to be operating out of normal operation, and so the operation and performance of the device in these circumstances will need to be verified in the customers' specific application. Output power for example will be limited, and efficiency performance will not be optimized at lower voltages. Our FAEs can also guide you by contacting us at

What standard do you use to calculate MTBF?

The failure rate and mean time between failures (MTBF) are typically calculated at max output power and an operating ambient temperature of +40°C. Our latest products mainly use Telcordia SR-332 Issue 4 Method 1 to calculate the mean steady-state failure rate and standard deviation. Telcordia SR-332 Issue 4 also provides techniques to estimate the upper confidence levels of failure rates based on the mean and standard deviation. Our Technical Specifications therefore typically provide both a standard MTBF figure, and an MTBF figure at 90% confidence factor.

Some of our devices designed for Industrial and Rail applications also include MTBF calculations based on the MIL-HDBK-217F reliability method. Please check individual Technical Specifications for more details.

How do I convert airflow from LFM or m/s to CFM and vice versa?

Firstly, to convert common values of air velocity in meters per second to Linear Feet per Minute (LFM), you can use the table below which shows common approximations:

0.25 m/s = 50 LFM
0.5 m/s = 100 LFM
1.0 m/s = 200 LFM
1.5 m/s = 300 LFM
2.0 m/s = 400 LFM
2.5 m/s = 500 LFM
3.0 m/s = 600 LFM

When considering the air volume that is being moved rather than simply its velocity, which is commonly used by fan manufacturers for example, then Cubic Feet per Minute (CFM) is often referred to as the unit of measurement.

To convert CFM measurements to LFM, use the following equation:


Where CFM = Cubic feet per minute of air volume and AREA = the area of the opening in square feet.

What do you mean by "Peak Power" and "Peak Current" listed on some your products?

Most of our products are designed and specified to provide a defined amount of continuous power to its load under suitable cooling conditions, ranging from natural convection, to forced air cooling, or conduction cooling to a heatsink or cold-wall for example. This continuous power, often referred to in the processor world as the Thermal Design Power, or TDP, is the maximum power the converter can deliver assuming sufficient cooling is provided to keep the key reference temperatures below the stated maximum values in the Technical Specification (typically 125°C).

More and more applications such as those using CPUs, GPUs, FPGAs and ASICs however also require the power supply to be able to deliver a peak power or current for very short durations during periods of peak compute processing. The time period can range from a few microseconds to tens or hundreds of milliseconds, and so many of our newer devices designed for these applications will have both a continuous power or current rating and a peak power or current rating defined. The ability of the module to be able to deliver the peak power or current will be detailed in the Technical Specification, for example as outlined HERE for the BMR4913208/857 device which has a continuous TDP rating of 1540W and a peak power rating of 2450W.

Do you offer thermal models for your DC/DC products?

Yes, we offer FloTHERM models which are available for many of our products in .PDML file format. Those available are presented both on the relevant product landing pages, and in the Downloads section. If you can't find the specific one you need, then please contact us at

Do you offer 3D CAD files?

Yes, we offer 3D STEP files in .STP format for many of our modules. Due to the wide number of different mechanical options that exist (pin types, pin lengths, open frame, baseplated, etc.), it's difficult to post every available model under the Additional Resources section of each products' landing page, or in the downloads section of our website, but if you don't see what you need there please request a specific 3D model of the exact part number you need by contacting us at

Do you offer alternatives to POLA standard Point of Load converters?

Yes, and a useful cross reference list to support you to find suitable alternatives can be found HERE

Do you have alternatives to the discontinued Intel/Enpirion PoL converters?

We can offer alternatives to the Enpirion module solutions with outputs above 4 A, but of course a change in layout will be necessary since the Enpirion solutions were not standard footprints. A useful cross reference list to support you can be found HERE.

What protection features do your products offer?

Please consult the specific technical specification for the device in question for details, but typically our products include input Under Voltage Lock Out (UVLO), output Over Voltage Protection (OVP), output Over Current Protection (OCP) and Over Temperature Protection (OTP). Digital products offer the ability to configure both the protection parameters as well as the protection behavior.

What does "hiccup mode" protection mean?

The term "hiccup mode" in this case refers to a form of overload protection mechanism, for example over current protection, where if an output over current is detected, then the module will continuously disable the output and then make continuous restart attempts until the fault is removed.

What's the difference between Isolation & Insulation levels?

The isolation level of an isolated DC/DC converter usually refers to the voltage which may be applied between input and output for a short duration without current flowing, usually as a result of the breakdown of the insulation material used to provide the galvanic isolation. For baseplated converters, the isolation level from Output to Baseplate and Input to Baseplate are also usually tested and specified.

The Insulation Level on the other hand refers to the method used to physically provide the galvanic isolation, and is usually characterized in 5 different classes – Functional/Operational; Basic; Supplementary; Double and Reinforced.

More information is available in Technical Paper 018

What is meant by transient response?

When the load current at the output of a converter changes suddenly, there will be a reaction by the output voltage falling or rising suddenly too. The ability of the converters control loop to correct this change to the output voltage quickly and controllably back to the setpoint value is known as its transient response. The key parameters to consider in terms of transient response are typically the overshoot/undershoot voltage and the settling/recovery time, both of which should be minimized.

More information on optimizing transient response in Digital POLs can be found in Application Note 306

How should I store and handle your products?

Products intended for Pb-free reflow soldering processes are delivered in standard moisture barrier bags according to IPC/JEDEC standard J-STD-033 (handling, packing, shipping and use of moisture/reflow sensitivity surface mount devices).

Using products in high temperature Pb-free soldering processes requires dry pack storage and handling. In case the products have been stored in an uncontrolled environment and no longer can be considered dry, the modules must be baked according to J-STD-033.

Please note that our products are to be stored and handled as ESD sensitive devices and are delivered as such.

Can I use reflow soldering to mount your through hole parts?

This manufacturing technique is often referred to as "Pin-in-paste" (PiP). The holes in the host PCB are overprinted with solder paste, then the DC/DC device is pressed down through that paste into the mounting holes, before the entire board then goes through a reflow solder process where the solder is then drawn up through the fillet to complete the solder joint.

Some of our products have been qualified for use with this manufacturing method. Those that are suitable will be highlighted in the Ordering Information section of the Technical Specification. To ensure reliable mounting, these devices are baked before being packed in a hermetically sealed dry pack before shipment. Options exist for the types of tray that the devices are shipped in. An example can be seen within the BMR480 series as shown HERE.

What is the MSL rating of your devices?

The Moisture Sensitivity Level (MSL) of a device is an electronic standard (J-STD-020) which represents the time period in which a particular moisture sensitive non-hermetic surface mounted device (SMD) can be exposed to ambient room conditions (≤30°C and 60% relative humidity) without the need for additional baking before undergoing a Pb-free reflow process to avoid reliability concerns such as cracks and delamination during the solder reflow process due to any residual moisture ingress.

Products from Flex Power Modules that are intended for Pb-free reflow soldering during the Customer’s manufacturing process, which include all SMD versions and through-hole products that are specifically approved for pin-in-paste manufacturing are classed as MSL 3.

These devices are baked and packaged in vacuum packed Moisture Barrier Bags (MBB) together with a desiccant and a humidity indicator card, and the seal should only be broken at the time of use. Once the seal is broken, the floor life at ≤30°C and 60% relative humidity of any remaining parts is 168 hours (7 days), before additional baking will be necessary to ensure reliable use during Pb-free reflow soldering. The required bake conditions are according to those specified by J-STD-033.

The shelf life for dry packed SMT or PIP devices will be a minimum of 12 months from the bag sealing date when stored in a noncondensing atmospheric environment of <40°C / 90% RH. The included humidity indicator card should be checked on opening the seal as it will indicate if any moisture has entered the bag, and will dictate if the parts should be baked before use.

Can I use water washing during manufacturing?

Products are qualified for water washing according to IEC 60068-2-45 XA, method 2. However, it is imperative that sufficient drying time is considered to avoid any problems. Our FAEs can also guide you by contacting us at

Where could I find a list of technical abbreviations?

We have produced a handy list of common technical abbreviations used within the power industry, and those industries of our typical customers for your reference. The list can be found HERE

Flex Power Designer

What is the Flex Power Designer tool?

We have developed the Flex Power Designer tool in order to help you to sketch, simulate, configure and monitor your digital power system. It is free to download the Flex Power Designer Tool. You can watch a short demonstration video HERE.

What operating system does the Flex Power Designer work with?

The Flex Power Designer software package requires Microsoft .NET Framework 4.6.2, and is supported by the following operating systems: Windows 8, Windows 8.1, Windows 10 and Windows 11.

What is PMBus?

PMBus® ( is a non-proprietary standard for communication with power converters of all types. The PMBus specification is in three parts.

  • Part I describes how data is moved from one device to another. It is based on the SMBus specification with a few additional requirements specific to the PMBus.
  • Part II of the PMBus specification describes the command language, data formats including numerical formats, how communication faults are handled, and other requirements.
  • Part III of the PMBus specification was introduced with Revision 1.3. Part III describes the AVSBus which provides a fast and simple interface for logic devices (such as microprocessors, ASICs, and FPGAs and other programmable logic devices) to quickly control their supply voltage. AVSBus also provides for some monitoring of the power converter attached to the devices. The physical layer of the AVSBus is very much like the common SPI.

Why does TI's USB-TO-GPIO2 adapter not work with my copy of Flex Power Designer?

TI released a new version of their USB-TO-GPIO2 adapter which is recognized by it having the 2022 date printed on it rather than the original 2006 USB-TO-GPIO adapter. The new USB-TO-GPIO2 adapter uses a different core processor than the USB-TO-GPIO. This provides the newer USB-TO-GPIO2 with a range of improved functionalities that include BUS monitoring, 1MHz clock speed support, on-board burst and script modes we well as other features. The 2022 USB-TO-GPIO2 adapter is only compatible with Flex Power Designer version 4.6.0 or later, which is to be released in March 2024.

What are the key features of the Flex Power Designer tool?

Flex Power Designer (FPD) goes beyond simple converter configuration, and provides an overview of your whole power system, enabling you to define relationships across rails, including Phase Spreading, Sequencing and Fault Spreading.

The built-in simulation enables power-stage analysis to optimize tuning and visualize design behavior against your particular power requirements such as Transient Response, Output Impedance and Power Dissipation.

The software also includes thermal behavior simulation, graphically showing the dependencies between multiple user defined parameters such as ambient temperature, board temperature, wind speed, board thickness and copper thickness.

An additional feature recently added is a numerical conversion calculator which enables designers to work with the various alternative number formats for monitoring data allowed in the SMBus/PMBus standards. It also includes a display address resistor suggestion feature, which calculates suggested values for the PMBus address resistors SA0/SA1, as well as offering the ability to monitor common parameters from other vendors' power products.

It is free to download the Flex Power Designer Tool

A brief introduction to the key features of Flex Power Designer can be seen below.