Test protocol
Comparison of DC-DC modules: step-down, step-up, and universal
Boards installed inside devices: in a car, a charger, or a DIY project. Their claimed specs often don't match reality, so the table lists what the tests actually showed.
- 8models
- 2review recommends
- 2016–2020review years
In brief: In the table 8 models: review recommends 2, with reservations 6. Lowest ripple in the test: Step-down, up to 10 (12) A, 30 mV. Highest current: Dual-channel 5 V + 3.3 V, 25 A.
Quick guide: what to choose
5 V with plenty of headroomTPS40057 5 VHandles up to 9.5 A despite being rated for 5 A, costs next to nothing, and the review gives it an unequivocal recommendation.
High current at low voltageDual-channelAt currents up to 25 A, the voltage changes by just 11 mV, with ripple up to 35 mV.
Input voltage can be above or below the outputLTC3780Cars, solar panels, batteries. Keep an eye on transistor temperatures.All models
| Model | Current, test | Ripple, test | Review conclusion | ||
|---|---|---|---|---|---|
| TPS40057 5 V 5 A$1.43 · 2019 | 9.5 Ahandles up to 9.5 A | 100 mVabout 100 mV | Recommended | Small, inexpensive, and an easy recommendation. It’s best to remove the input diode: efficiency improves and heat goes down. |
| Dual-channel 5 V + 3.3 V$0.51 (¥3.50) · 2020 | 25 Atested up to 25 A | 35 mV30–35 mV at 24 A | Recommended | I really liked these: compact, with overheat and overload protection and fan control. “Definitely worth buying” if you find them at a reasonable price. |
 | Step-down, up to 20 A$5.92 · 2020 | 15 A15 A continuous with cooling | 80 mVabout 80 mV | With reservations | Mediocre, but perfectly usable. Consider adding cooling; current adjustment only starts at 0.7 A, and the terminal blocks are flimsy. |
 | Step-down, up to 10 (12) A$3.34 · 2020 | 10 Aup to 10 A without issues | 30 mV25–30 mV at 10 A | With reservations | Low ripple, but sloppy assembly. The review recommends spending a couple of dollars more for the 20 A board. |
 | “10 A” step-down$3.56 · 2016 | 8 Aup to 6–8 A in practice | —50 mV claimed | With reservations | Suitable for undemanding loads and LEDs. The output voltage jumps around, and you can’t charge lithium batteries without modifications. Typestep-downRead review |
 | With QC 3.0$3.28 · 2018 | 4 A3.5–4 A continuous at 5 V | 175 mV150–175 mV at 5 V | With reservations | I liked it more than I didn’t: stable operation and reverse-polarity protection, but high ripple and 82.9–94.3% efficiency. |
| LTC3780$14.30 · 2016 | 8 A8 A continuous, 10 A peak | 160 mV60–160 mV (50 mV claimed) | With reservations | Decent efficiency across a wide range; it really comes into its own when the input can be either above or below the output. Heat dissipation from the transistors is poor. |
 | 400 W step-up$3.86 · 2020 | —up to 131 W in testing with 12 V input | 1200 mVup to 1.2 V | With reservations | It’ll work, but needs modifications right away: capacitors, thermal paste, and terminal blocks. The ripple should be filtered; the only short-circuit protection is a fuse. |
Conclusion — a brief summary of the review’s findings. See the review itself for details and measurement conditions. Prices are as of the review date and may have changed since then. A dash means this value isn’t mentioned in the review; it’s often shown in the specs photo. The scales show how each model compares with the others on this page: green — good, yellow — average, red — poor.
Frequently asked questions
Which inexpensive 5 V DC-DC module should you choose?
TPS40057: rated for 5 A, it handles up to 9.5 A, with around 100 mV ripple; the review gives it an unequivocal recommendation. It's best to remove the input diode: efficiency improves and heating decreases.
Which step-down module is suitable for high current?
The dual-channel 5 V + 3.3 V module handled up to 25 A in testing, with 30–35 mV ripple. The adjustable module rated “up to 20 A” actually delivers 15 A continuously, and only with cooling.
Do “10 A” modules deliver their rated current?
Not always. The “10 A” module reviewed in 2016 actually worked up to 6–8 A, while the 10 (12) A board handled 10 A without problems. That's why the table lists the current measured in testing, not the figure on the label.
Which module do you need if the input voltage can be either higher or lower than the output?
LTC3780 step-up/step-down converter: 6–30 V input in testing, 1–30 V output, 8 A continuous and 10 A peak. Suitable for cars, solar panels, and batteries, but keep an eye on transistor temperature.
What is the ripple on the 400 W boost converter?
Up to 1.2 V, so an additional output filter is needed. In testing, with 12 V input, the module delivered up to 131 W. It also needs some work right out of the box: capacitors, thermal paste, and terminal blocks.
