A Look at DCDC Boost Converters

We were looking for a 3V to 7-8V DCDC Boost converter module recently and had a particularly hard time finding a suitable candidate. The current requirements were 0.6A continuous and 2.5A peak. Here are few of the options we considered.

Option 1 – XL6009 Module
Option 2 – LM2577 Module
Option 3 – LM2587 Module

All of these are marketed to work in an input voltage as low as 3V.

Here are some screencaptures of sales pages from Aliexpress sellers.

Option 1 – XL6009 Boost Converter Module Aliexpress sales page
Option 2 – LM2577 Boost Converter Module Aliexpress sales page
Option 3 – LM2587 Boost Converter Module Aliexpress sales page

And here are screencaptures of resellers who are also marketing their wide input voltage range.

Option 1 – XL6009 Boost Converter Module Reseller Page
Option 2 – LM2577 Boost Converter Module Reseller Page
Option 3 – LM2587 Boost Converter Module Reseller Page

On bench testing using a power supply and discharger, we found that Option 1 and Option 2 did not meet the desired specifications.

Websites are falsely claiming their wide input range all the way down to 3V.

Option 1 – XL6009 based module goes into thermal runaway around 3.5V input, and is not able to maintain a steady 7.2V output at 400mA.

Option 1 – XL6009 Module being tested

Option 2 – In the LM2577 based module, we found that the LCD starts to flicker around 4.9V input even at no load! This module definitely does not meet the marketed specifications of 3V input.

Option 2 – LM2577 Module being tested

Out of the options we considered, we found that Option 3 was the best out of the lot. It does not go into thermal runaway even at 2.8V input, and operates decently well up to 3.4-3.5V input maintaining a 7.2V output at 500mA continuous. In our testing conditions, we did notice however that it the module gets considerably hot during operation, and with electrolytic caps on the board we don’t recommend running the board at high temperatures. We would recommend adding heat sinks to the LM2587 IC for proper heat dissipation and long term use.


Current Sensing Techniques for Battery Management Systems

During the initial design stage, we were looking at multiple options for sensing current that would flow in and out of the battery pack. As many of you know, there are mainly two approaches to sense current, these are can be classified as: Invasive – Sensing currents using shunt resistors or similarNon-Invasive – Sensing using...
Continue Reading

Don’t let a decoupling capacitor ruin your circuit

Decoupling capacitors are commonly found in circuits and can cause unintended issues if the design is not thought through fully. Let’s first understand what decoupling capacitors are. There are usually 0.1uF, and sometimes 2.2nF capacitors that are placed between the supply rails and ground to help prevent the transmission of noise through the power lines in...
Continue Reading

Importance of Isolation Monitoring in Electric Vehicles

With the recent news of Audi E-tron recalls due to battery pack leakages, the following information on isolation is important to understand and consider. The article talks about moisture leak into the battery pack, so the first question to ask is why does increased moisture in the pack lead to issues? Here are a few...
Continue Reading
2 Responses

Leave a Reply

error: Content is protected