Unique Boost Converter Module

--by Maninder Bir Singh Gulshan, Prerna Gupta and Sanjeev Kumar

Battery cells are the most commonly used energy source to power portable electronics. Be it a simple alarm clock or an IoT sensor node or an intricate mobile phone everything is powered by batteries. In most cases these portable contrivances need to have a diminutive form factor (package size) and hence it is powered by a single cell battery, like the popular CR2032 Lithium cell or the other 3.7V lithium polymer or 18650 cells. These cells pack in high energy for its size but a prevalent disadvantage with these cells is with its operating voltage. A typical lithium battery has a nominal voltage of 3.7V, but this voltage can go down as low as 2.8V when plenarily drained and as high as 4.2V when plenarily charged which is not very desirable for our electronics designs which either work with regulated 3.3V or 5V as operating voltage.

This brings in the desideratum for a boost converter which can take in this variable 2.8V to 4.2V as input voltage and regulate it to constant 3.3V or 5V. Thankfully though there subsists an IC called BL8530 which does precisely the same with very minimum external components. So, in this project we will build a low cost 5V booster circuit that provides a constant regulated output voltage of 5V from a CR2032 coin cell; we will additionally design a compact PCB for this boost converter so that it can be utilized in all our future portable projects. The maximum output current of the boost converter will be 200mA which is adequate to power rudimentary microcontrollers and sensors. Another advantage of this circuit is that, if your project requires a regulated 3.3V in lieu of 5V the same circuit can additionally be habituated to regulate 3.3V by just swapping one component. This circuit can additionally work as Power Bank to power up diminutive boards like Arduino, STM32, MSP430 etc. We aforetime built homogeneous kind of boost converter utilizing Lithium Battery to charge a cell phone.

• MicroUSB Type AB
• BL8530-5V Booster IC (SOT89)
• 47uH Inductor (Package 1210) - LQH32PB470MN0L
• SS14 Diode (SMD)
• 100uF 50V Tantalum capacitor
• Coin Cell Holder

• Brand Name: WXFJYLYI
• Condition: NewType:
• Logic ICs
• Package: SOT89
• Dissipation Power: standard
• Model Number: BL8530
• Operating Temperature: standard
• Supply Voltage: standard

The design requisites for a Single cell Boost converter will be different from that of a mundane boost converter. This is because here the energy from a battery (coin cell) is being boosted into output voltage for our contrivance to work. So care should be taken that the booster circuit utilizes the maximum of the battery with high efficiency to keep the contrivance powered on for as long as possible. When culling the booster IC for your designs you can consider the following four parameters. You can withal read the article on Boost Regulator Design to ken more about it.

Start-up Voltage: This is the minimum required Input voltage from the battery for the boost converter to commence operating. When you power on the boost converter the battery should at least be able to provide this commencement-up voltage for your booster to work. In our design the commencement-up voltage required is 0.8V which way below any plenarily discharged coin cell voltage.

Hold-on Voltage: Once the contrivance is powered with your boost circuit the battery voltage will commence to decline since it is giving out potency. The voltage till which a booster IC will hold its performance is called the hold-on voltage. Below this voltage the IC will stop function and we will get no output voltage. Note that hold-on voltage will always be less than start-up voltage. That is the IC will require more voltage to commence its operation and during its running state it can drain the battery way below that. The hold-on voltage in our circuit is 0.7V.

Quiescent current: The magnitude of current our booster circuit is drawing (wasting) even when no load is connected on the output side is called as Quiescent current. This value should be as low as possible, for our IC the value of quiescent current is between 4uA to 7uA. It is very consequential to have this value low or zero if the contrivance is not going to be connected to load for a long time.

On-Resistance: All boost converter circuit will involve a switching contrivance like MOSFET or other FETs in it. If we are utilizing a converter IC then this switching contrivance will be embedded inside the IC. It is paramount that this switch has very low on-resistance. For example in our design here, the IC BL8530 has an internal switch with on-resistance of 0.4Ω which is a decent value. This resistance will drop a voltage across the switch predicated on the current through it (Ohms law) thereby decrementing the efficiency of the module.

Full Process is shown using Screenshots Step-wise.

Now we have got the PCB design and it’s time to order the PCB’s. For that, you just have to go to JLCPCB.com, and click on “QUOTE NOW” button.

JLCPCB are also sponsor of this project. JLCPCB (ShenzhenJLC Electronics Co., Ltd.), is the largest PCB prototype enterprise in Chinaand a high-tech manufacturer specializing in quick PCB prototype and small-batch PCB production. You can order a minimum of 5 PCBs for just $2.

To get the PCB manufactured, upload the gerber file you downloaded in the last step. Upload the.zip file or you can also drag and drop the gerber files.

After uploading the zip file, you’ll see a success message at the bottom if the file is successfully uploaded.

You can review the PCB in the Gerber viewer to make sure everything is good. You can view both top and bottom of the PCB. After making sure our PCB looks good, we can now place the order at a reasonable price. You can order 5 PCBs for just $2 but if it’s your first order then you can get 10 PCBs for $2.

To place the order, click on “SAVE TO CART” button. My PCBs took 2 days to get manufactured and arrived within a week using DHL delivery option. PCBs were well packed and the quality was really good.