28 V / 48 V Brick DC/DC Module Selection Guide

A nominal 28 V or 48 V bus is not an operating input range

Start with the lowest and highest voltage that can reach the module during normal equipment operation. Include source tolerance, wiring drop, startup and the intended load conditions. List exceptional events separately, such as reverse polarity or surges, and identify whether external protection is required. A survival limit is not a continuous operating rating.

Select against the input range of the exact catalog row and the current model specification. Jingmu's listed families have model-dependent input windows, so neither a nominal 28 V label nor a nominal 48 V label establishes one common range for every output variant. Do not extend a listed range from a neighboring row or another power level.

Specify output voltage, current and the real load profile

State the required output voltage, steady-state current and permissible voltage deviation, then describe load steps, startup demand and connected capacitance. A wattage figure alone is insufficient: output-current limits, transient behavior and permitted capacitance can determine whether a module suits the load.

Treat the public 80–420 W span as coverage across different listed series, not as every rating in every brick size. Confirm how much output is permitted at your input voltage, local temperature and cooling condition. Do not assume that the headline rating is continuously available at every operating corner.

Brick format is a mechanical starting point, not a drop-in guarantee

The 1/16-, 1/8- and 1/4-brick labels help narrow the package family. They do not establish an identical pinout, height, baseplate, mounting arrangement or control interface. Verify the outline, pin assignment, pin length, keep-out areas and assembly method against the exact drawing.

Check input-to-output isolation, permitted working voltage and system grounding separately. An isolation test voltage does not by itself establish a continuous working-voltage rating or equipment safety approval. Confirm the applicable documentation and system requirements before treating one module as a replacement for another.

Make thermal and electrical integration part of the shortlist

Give the supplier the enclosure conditions, local ambient temperature, airflow direction and speed if relevant, heatsink or baseplate arrangement and nearby heat sources. Request the derating information applicable to that setup. A larger nominal wattage does not eliminate a cooling constraint, and an enclosure temperature is not automatically the module's local ambient condition.

Review input filtering and inrush, source stability, output capacitors, remote-sense wiring if provided, startup, enable behavior and protection recovery. Confirm ripple and load-step results under stated measurement conditions. Manufacturer application notes provide background, but their ratings or installation rules must not be transferred to a Jingmu-listed module without its own specification.

Add the digital functions you need, not functions implied by the label

If the equipment needs monitoring or configuration, list the required signals and functions before choosing a module. Ask which readings exist, their accuracy and update rate, which settings are writable and which protections operate independently of the host. Confirm the electrical interface, protocol, address method and supported commands for the exact model.

Request startup defaults, communication-loss behavior and configuration retention rules. Do not assume that a digital brick includes a management bus, remote adjustment, sequencing, fault logs or a particular interface. Document unavailable functions early so the system design can account for them.

Use the public catalog as a shortlist and send a complete inquiry

The public digital-power tables list six families and 66 series references covering nominal 28 V / 48 V buses and three brick formats. These are series-level references transcribed from supplied product material, not an independently measured performance report. Placeholder characters in a series reference are not a complete orderable part number.

For a useful selection response, email market@jingmusecurity.com with minimum and maximum input voltage, output voltage and current, load steps, cooling and mechanical limits, required control or monitoring functions and intended quantity. The website provides specifications and selection guidance; model-specific documents and availability are handled by email rather than a public file-download library.

Frequently asked questions

Does a nominal 48 V input mean every module accepts the same voltage range?

No. Input limits differ between listed series and output variants. Check the exact row and current model specification; neither the nominal bus label nor another row establishes the required range.

Can any 1/8-brick module replace another 1/8-brick module?

Not without checking. Confirm outline, height, pinout, mounting, input and output limits, enable behavior, isolation, cooling and interface requirements. The brick label alone does not establish drop-in compatibility.

Can every listed power rating run continuously in a sealed enclosure?

That is not established by the public tables. Continuous output depends on the selected model's input and thermal conditions. Request its applicable derating data and validate it in the intended enclosure.

What information makes a DC/DC module inquiry useful?

Provide input minimum and maximum, output voltage and current, load profile, cooling and mechanical constraints, required digital functions and quantity. Ask for the exact model specification and complete order code before design commitment.

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