**SMD Electrolytic Capacitor Voltage Codes: A Comprehensive Guide**

### Introduction

SMD (Surface Mount Devices) electrolytic capacitors are widely used in electronic circuits due to their compact size, high capacitance, and low equivalent series resistance (ESR). However, understanding the voltage codes on these capacitors can be challenging, especially for beginners. In this article, we will explore the voltage codes of SMD electrolytic capacitors, their meaning, and how to read them.

### Voltage Codes: What Do They Mean?

The voltage code on an SMD electrolytic capacitor typically consists of two or three digits, followed by a letter or a symbol. The digits represent the rated voltage, while the letter or symbol indicates the tolerance or other characteristics of the capacitor.

**Rated Voltage (Digits)**

The rated voltage is the maximum voltage that the capacitor can withstand without being damaged. The digits represent the voltage rating in volts, with the following conventions:

**2 digits**: The rated voltage is the value indicated by the two digits. For example, "16" means the capacitor is rated for 16 volts.**3 digits**: The first two digits represent the significant figures, and the third digit represents the multiplier. For example, "106" means the capacitor is rated for 10 x 10^6 = 16 volts.

**Tolerance and Characteristics (Letter or Symbol)**

The letter or symbol following the digits provides additional information about the capacitor's characteristics. Common letters and symbols include:

**K**: ±10% tolerance**M**: ±20% tolerance**J**: ±5% tolerance**Z**: ±0% tolerance (no tolerance, but may have a smaller capacitance range)**B**: Bi-polar capacitor (non-polarized)**P**: Polarized capacitor (with polarity markings)

### Examples and Interpretation

Let's take a look at some examples of SMD electrolytic capacitor voltage codes and their interpretation:

**16K**: Rated for 16 volts, ±10% tolerance**105M**: Rated for 10 x 10^5 = 1.05 volts, ±20% tolerance**220J**: Rated for 22 volts, ±5% tolerance**16Z**: Rated for 16 volts, no tolerance (but may have a smaller capacitance range)**100B**: Bi-polar capacitor, rated for 10 volts

### Conclusion

Understanding the voltage codes on SMD electrolytic capacitors is crucial for selecting the right component for your electronic circuit. By recognizing the rated voltage and tolerance, you can ensure that your capacitor operates within its specifications, providing reliable performance and longevity. Remember to always check the datasheet and manufacturer's recommendations when working with SMD electrolytic capacitors.