9.8 TOTAL SCORE

MDP-P906 Power Supply

Tools

The MDP-P906 is a nifty little power supply which tries to convert any consumer-grade DC source into a stable, precise and regulated output. It accomplishes this task with ease, all while fitting easily in your pocket. So much tech in such a little box for such a low price - this one is hard to pass!


Build quality 10
Implemented technology 10
Ease-of-use 9
Price/performance ratio 10
PROS
  • Budget-friendly
  • Absolutely tiny
  • High-precision output
CONS
  • UI could use some improvements

Miniware MDP P906 review

Introduction

Miniware makes tiny things. The company specialises in shrinking usually bulky and hefty equipment into tiny pocket-sized gadget while sacrificing the least amount of features. Naturally, this is a tricky feat which requires a good bit of engineering know-how.

Best known in the maker circles for their TS-series soldering irons, Miniware is a company which produces quite the array of products – from tiny portable oscilloscopes and logic analysers to SMD tweezers (our review here) and more. So far we’ve had quite a positive experience with their products, and the general community consensus is similar.

This is why we’ve already got high hopes for the review unit we’ve got in our hands – the MDP-P906 PSU. The manufacturer provided us with the unit free of charge, but does not in any way influence our opinions stated here.

Look and feel

As always, Miniware ships their products in stylish, well-designed boxes with gorgeous graphics and a great feel. We’re aware that “box feel” isn’t high up on the priorities list on a bit of workbench kit, but first impressions definitively scale expectations appropriately.

The great presentation doesn’t stop! Inside the outer cardboard packaging is another, hard plastic box – a staple of Miniware’s packaging design – which protects the unit itself and houses accessories and the manual. Two cables are also provided for connecting circuits to the P906. These feel pretty great, with gold plated tips and quality silicon coating. The unit itself is also pretty solid, with an outer aluminium housing and gold-plated terminals. An OLED screen graces the front panel along with a simple three-button setup and a rotary encoder on the right side. It’s minimalist, but it does the job.

Specs

This time around, there are some incredible specs under-the-hood. The MDP-P906 isn’t Miniware’s first foray into the PSU market, but rather a part of an ecosystem comprising of the MDP-P905 and MDP-P906 power modules and the MDP-XP wireless display. The reason we’ve brought all of this up is simple: the P905 was already a powerful module at 90 W, while the MDP-P906 more than triples that spec to 300 W while retaining an almost identical footprint. Quite impressive for a smartphone-sized device.

Similar to their newest TS101 soldering iron, the P906 features dual power options – a USB-C connector and a DC barrel jack. Both of these accept a wide variety of voltages: the USB port supports PD chargers (output power limited to around 100 W in this case, however) and the barrel jack accepts anything between 4.2 and 30 V. Similarly, the PSU itself can output up to 30 V at up to 10 A. It offers various over-voltage and over-current protections and can even safely handle a short circuit or two.

There’s also the standard two supply modes – voltage limiting and current limiting, as well as the option of connecting multiple MDP-P906 units in parallel or series for obtaining a maximum of 20 A and 60 V, respectively.

Perhaps the most impressive are the minute dimensions of the entire MDP series of devices – at only 11.2 cm wide and 6.6 cm high. Thermals must have been a big concern when packing so much tech in such a tiny package as evident by the surprisingly loud fan which greets the user at full speed upon every power-up (for a few seconds, thankfully, and it rarely runs at other times).

While yes, the MDP-P906 does rely on an external power brick to actually convert the mains AC to an appropriate DC input, relegating some of the work to an external (most likely) switching-mode PSU, it’s still mighty small, even if its real job is acting as a precision DC-to-DC converter. The reason this was important to mention is simple – large lab bench supplies have bulky toroidal coils which step the voltage down in a much more stable fashion than digital switching-power supplies (which is what most wall adapters are nowadays), which tend to introduce noise issues. This does mean that DC filtering in the The MDP-P906 is a nifty little power supply which tries to convert any consumer-grade DC source into a stable, precise and regulated output. has an extremely important role to fulfil if it wants to compete with the output stability of more traditional instruments.

There’s also a 2.4 GHz radio built-in for communication with the aforementioned MDP-XP display. As of the time of writing this review, it isn’t in stock, so we can’t comment more on this function, but we hope to revisit this aspect in the future.

UI and ergonomics

Surprisingly enough, a lot can go wrong when operating power supplies. Bad UIs can increase the chance of operator mistakes, and operator mistakes can be costly when it comes to power supply apparatuses. Luckily, the UI is pretty simple to use – the big rotary encoder controls parameter changes, while the three buttons select the respective parameter, open the main menu and start and stop the power delivery. It’s as simple as that.

The main menu also offers very limited options, which in this case is great. There’s info on the wall adapter output (extremely useful feature for troubleshooting), temperature and version numbers. There’s nothing to actually change here – which renders the dedicated “menu” button somewhat superficial. We feel like it could have been a secondary long-press function, like the lock is, which could have brought the button total down to two.

The rotary encoder works great and makes selecting desired voltages and current limits easy. While the output isn’t enabled, the display shows set values, and a quick press of the first button cycles through parameters, clearly reflected on the display. Where issues for us arise, however, is setting parameters while the output is running. The nice settings screen gets yanked away from us, as the two large numbers get overtaken by live output voltage and current measurements (which is a great feature). When setting the new parameter, it overtakes the power measurement (another smart choice), but before actually spinning the dial, the only indication of what you’re about to change is given by a tiny letter roughly in the middle of the screen. This is a major oversight as multiple times we’ve changed the wrong parameter by mistake. It’s not a huge deal when unintended current limit adjustments happen, but definitely a huge issue when such voltage adjustments occur, and especially so when working with sensitive circuitry.

Our solution would be simple – highlight the parameter that’s about to change in the same fashion as when the generator is stopped and display the new value on the side, like it currently already is. Maybe less elegant, but way clearer – which should be the main priority when designing an interface for a tiny display.

Performance

We’ve arrived at the most important stop on our journey! While impressively specced and meticulously crafted, we’ve noticed potential weak points in the design. In this paragraph we’ll see if they’ve been sufficiently accounted for – and we’ve got high hopes for a positive answer here.

We’ve tested the output stability and measured the precision of the outputs with our trusty Fluke 289 and have gotten amazing results across the board.

Fluke 289 MDP P906
82,78 mADC 0,082 ADC
2,9984 VDC 2,994 VDC
3,0283 VDC 3,024 VDC
4,1099 VDC 4,108 VDC

Let’s start with the stability. While yes, as expected, the voltage did have some minor fluctuations which registered on the bar-graph of our DMM, probably due to the noise introduced by the external switching supply, it was extremely minuscule (less than 0.8 mV peak-to-peak at its worst under full 30 V load in our testing). This, of course, depends heavily on the quality of the external adapter (but according to its spec, the very adapter we’ve used normally introduces around to 200 mV of noise, or 1% of its rated power output, which is the usual). This means that the internal circuitry of the MDP-P906 does wonders to filter the output. While not as stable as a linear supply, we doubt many circuits would be noticeably affected by this.

The precision is top-notch, however, and doesn’t leave much to be desired. Both the set values and the measured values are accurate, as confirmed in several of our tests. Voltage readouts were a millivolt or so off, while current readouts were spot on. The unit also doesn’t suffer from voltage drops under high loads (or precision issues under tiny loads either, impressive!) and is generally extremely reliable. Current limiting also works perfectly, with precision down to the milliamp level.

Short circuit protection also works as planned. The unit itself does make a scary crackling noise, but there’s no sparking and no damage to either the circuit or the PSU. Great!

Thermal protection is also present, but we didn’t ever reach the point where a thermal shutoff was necessary. If embedding the supply in a cramped project full of already warm parts, it might come in handy, however.

Conclusion

The MDP-P906 is a curious little device. It’s not a “DC power supply” in the traditional workbench sense as it still requires an external power adapter to function – but it can take a whole array of input voltages and two different connector types, enabling you to turn almost any power adapter you’ve got lying around into a stable, precise and usable power source for labwork. We’ve even managed to power it off a computer USB port, with similar performance results as those described in the last section. In this sense, it’s more of a “filter” with plenty of features and protections expected from a full-size PSU. Its performance is great, especially when you factor in the size. Some UI improvements would be welcome, but it’s nothing that can’t be fixed in a firmware update (our firmware was the latest 1.33.121 version as of the time of writing).

Retailing for just $139 at various online storefronts, it’s definitely an attractive bit of kit. It packs a serious punch, both for the price and for the size. Miniware has done it again: affordable portability.

More information: https://www.miniware.com.cn/product/mdp-p906-mini-digital-power-supply/