Solution for Output Noise in the XH-M411 Boost Converter Module to Overcome Cellular Phone Charging Issues

I encountered a problem while using the XH-M411 boost converter module for powering a cellular phone. The issue arose when the phone was connected for charging; the charging process would intermittently stop and restart. Upon investigation, it was found that the voltage reading on the voltmeter connected to the XH-M411 module showed fluctuations specifically when the phone was connected. When a LED modules, DC motor was connected instead, no such voltage fluctuations were observed.

This instability in the output voltage was causing the phone to repeatedly start and stop charging. It was clear that the output noise and voltage fluctuations were significant enough to affect the phone’s charging circuitry.

Supplies for Solution

150 µF Electrolytic Capacitor:

1. Type: Electrolytic
2. Value: 150 µF
3. Purpose: Used for smoothing out low-frequency voltage fluctuations and ensuring a stable power supply to the connected device.

0.1 µF Electrolitic Capacitor:

1. Type: Electrolytic
2. Value: 0.1 µF
3. Purpose: Designed to filter out high-frequency noise and stabilize the output voltage by addressing quick voltage spikes and noise.

Perforated Pertinax

Suppies for Power Supply:

3 x Li-ion 18650 Batteries: Capacity: 2600mAh each

1 x Triple Battery Holder: A battery holder designed to accommodate and connect three 18650 batteries in series or parallel configuration.

1 x 10A 1S BMS (Battery Management System)

XH-M411 Boost Converter Module

1. DC Male and Female Connectors

Wires

I was unable to locate a datasheet for the XH-M411 boost converter module. Upon removing the aluminum passive cooler, I discovered that the module is equipped with an XL-6019F IC. I did not succed to find a solution related to mobile phone charging problems in the datasheet of this boost converter IC.

One of the key features of this XL6019 is its feedback mechanism, which helps maintain stable output voltage.

The 5th pin of the XL-6019 is specifically used for voltage feedback. This pin is crucial for the proper regulation of the output voltage. It provides a means to sample a portion of the output voltage and feed it back to the IC to compare with an internal reference voltage.

I currently do not have access to an oscilloscope, and as a result, I have not had the opportunity to analyze the output waveform. However, applying the noise reduction solution resolved the cellura phone charginh issue.

Adding capacitors or filters can help address noise-related issues and improve overall circuit performance.

Adding capacitors is a simpler solution, and I prefer this approach for its ease of implementation.

Basic Function of Capacitors

Capacitors are passive components that store electrical charge and release it back into the circuit when needed. This characteristic makes them highly effective at stabilizing voltage fluctuations in a circuit. In power supply or regulator circuits, capacitors typically serve two main functions:

1. Energy Storage: Capacitors help maintain a stable voltage by storing energy from the power supply and releasing it back into the circuit during voltage drops or surges. This helps keep the voltage steady and protects against sudden changes in the power supply.

2. Noise Filtering: Capacitors filter out high-frequency noise, providing a smoother voltage output. This ensures that the signals in the circuit remain clean and accurate, reducing adverse effects on sensitive electronic components.

The Rationale for Using Capacitors of Different Values:

1. Large Value Capacitors (e.g., 150 µF): Large capacitors are typically used to smooth out low-frequency voltage fluctuations (such as sudden drops in the power supply). They can store larger amounts of energy and smooth out broad voltage variations in the power supply. However, they are less effective at responding quickly to high-frequency noise.

2. Small Value Capacitors (e.g., 0.1 µF): Small capacitors are used to filter out high-frequency fluctuations and electrical noise. They can respond quickly, making them effective against sudden and fast voltage changes. They help suppress electrical noise or short-term voltage spikes.

In a regulator circuit, using both large and small capacitors together helps stabilize the output voltage by addressing different frequency ranges of fluctuations. In the context of phone charging issue, the contributions of these two types of capacitors are as follows:

150 µF Capacitor:

This capacitor filters out low-frequency fluctuations, providing a stable and smooth voltage to the phone charging circuit.

Boost modules like the XL6019F can create ripple signals when boosting voltage. The 150 µF capacitor helps smooth these signals and stabilizes the overall output voltage of the module.

0.1 µF Capacitor:

This capacitor filters high-frequency noise. Since the phone charging circuit is highly sensitive, even small and rapid voltage changes can disrupt the charging process.

The 0.1 µF capacitor provides cleaner output voltage by filtering high-frequency signals from the XL6019F’s operating frequency.

1) First, identify the (-) and (+) pins on each capacitor. The long pin is the (+) pin, and the short pin is the (-) pin. Additionally, there is a line marking on the side of the (-) pin.

2) Mount each capacitor on the perforated pertinax in a parallel arrangement.

3) Solder the capacitors onto the perforated pertinax.

4) Solder the cables and the USB socket onto the perforated pertinax.

More Stable Voltage: The capacitors help maintain a stable voltage in response to sudden changes in load, such as when the phone draws a burst of current. The 150 µF capacitor regulates low-frequency and wide voltage fluctuations, while the 0.1 µF capacitor filters out rapid and small voltage spikes. This minimizes both large and small voltage fluctuations.

Noise Reduction: Sensitive electronic devices, like phones, are particularly susceptible to noise and voltage fluctuations from the power supply. Small capacitors filter out unwanted signals and high-frequency noise, ensuring the device operates smoothly.

Improved Charging Process: When phones detect fluctuating or unstable voltage in their charging circuits, they may interrupt and restart the charging process. By adding these capacitors, a more stable voltage is provided, leading to a more stable charging process for the phone.

Conclusion:

By connecting the 150 µF and 0.1 µF capacitors in parallel, you effectively suppress both low-frequency voltage fluctuations and high-frequency noise, ensuring proper charging of the phone. This resolves the voltage instability issue and allows your phone to charge more efficiently.

The combined effect of both capacitors makes the power supply more stable and reliable.

I could not succeed to find the datasheet of XH-M411 boost converter module. The min input voltage of this module is reported different as 3V, 4V, 4.5V and 5V. For the module I have used in this article do not work under 4Vs.