πŸ”Ž Why ESD Protection Is Critical in Power Bank Design

With the development of fast charging technology and the widespread use of mobile devices, power banks have become frequently used consumer electronics products.

However, during daily use, frequent plugging and unplugging, direct human contact, and unstable external power environments often expose power banks to electrostatic discharge (ESD).

This article will analyze the ESD risks of power banks from a practical application perspective and introduce Semiware's professional protection solutions for battery paths and USB interfaces.

⚑ Why Do Power Banks Need ESD Protection?

In real-world usage environments, power banks are often exposed to multiple risks:

  • Dry environments (prone to static electricity buildup)
  • Direct human contact
  • Frequent plugging and unplugging of USB cables
  • Connecting to adapters or loads of varying quality

These risks make power banks high-risk devices for ESD. The lack of effective protection can lead to:

  • Potential damage to the charging IC/MCU
  • Abnormal device reset or crash
  • Decreased reliability, increasing after-sales risks

Therefore, introducing appropriate ESD protection devices in the early stages of design can effectively protect against these electrostatic discharge risks.

1️⃣ Battery Path ESD Protection – Safeguarding the Energy Core

Although the battery is located inside the power bank and seems "safe," it is actually directly connected to the system core through the following critical paths:

  • Charging Management IC
  • Power Path Management
  • MCU/Fuel Gauge

During dynamic processes such as charging, discharging, and load switching, transient voltage fluctuations and electrostatic coupling from insertion and removal can propagate along these paths, damaging sensitive chips.

πŸ”§ Semiware Solutions

SR05 ESD suppressor – Introducing the SR05 ESD protection device between the battery and critical system nodes effectively improves system robustness.

The core advantages of the SR05 include:

⚑ Ultra-fast response, suppressing ESD and transient surges

πŸ”’ Stable clamping voltage, protecting the charging IC input

πŸ”„ Improved system stability during charge/discharge switching

➑️ Product link: https://en.semiware.com/tvs-array/sr05/

2️⃣ USB Interface ESD Protection – The Most Common Discharge Entry Point

The USB interface is the most direct and frequent location for power banks to be exposed to ESD:

  • User plugging and unplugging cables
  • Direct contact of fingers with metal terminals
  • Potential differences between different devices

These can all generate high-energy electrostatic discharge (ESD) instantaneously, directly impacting MCU I/O and USB interface.

πŸ”§ Semiware Solution

SE10F10B5.0A ESD Diode - Placing an SE10F10B5.0A ESD diode near the USB interface can discharge electrostatic energy to ground immediately.

Key features include:

⚑ Ultra-fast response to high-energy ESD impacts

πŸ”» Low clamping voltage to protect MCU and charging IC pins

πŸ”Œ Low parasitic capacitance to maintain normal USB communication and charging performance

➑️ Product Link: https://en.semiware.com/tvs-array/se10f10b5-0a/

🧩 Design Recommendations

In power bank design, ESD protection effectiveness depends not only on the components themselves but also on the following factors:

  • Whether the components are placed close to the interface or a source of risk
  • Whether the grounding loop is short and direct
  • Whether a multi-level protection structure is formed on critical power paths

πŸ’‘ Semiware can provide more tailored protection recommendations based on your battery solution, USB interface type, etc.

If you are developing power banks, fast chargers, portable energy storage or charging devices, please feel free to contact Semiware. We will provide you with professional technical support from component selection to application solutions.

πŸ“©sales29@semiware.com