L78L05ABU
5V linear voltage regulators for stable power supply in compact SOT-89 packages
Manufacturer： stm
series introduction
# Introduction to the L78L05ABU Product Series
## 1. Overview
The L78L05ABU product series belongs to the family of low - dropout linear voltage regulators. These regulators are designed to provide a stable and regulated output voltage, making them essential components in a wide range of electronic circuits. The "L78L" indicates the general product line, while "05" specifies the output voltage of 5 volts, and "ABU" represents a particular variant with specific characteristics and package details.
## 2. Key Features
### 2.1 Output Voltage Regulation
The primary function of the L78L05ABU is to maintain a constant output voltage of 5V regardless of variations in the input voltage or load current. This is crucial for the proper operation of electronic devices that require a stable power supply. For example, in microcontroller - based systems, a stable 5V supply is necessary to ensure accurate data processing and reliable communication between different components.
### 2.2 Low Dropout Voltage
One of the significant advantages of this series is its low dropout voltage. Dropout voltage is the minimum difference between the input voltage and the output voltage required for the regulator to maintain regulation. The L78L05ABU has a relatively low dropout voltage, which means it can operate efficiently even when the input voltage is only slightly higher than the output voltage. This feature is particularly useful in battery - powered applications, where conserving battery life is essential. For instance, in a portable device running on a single lithium - ion battery (with a nominal voltage of around 3.7V), the low dropout voltage allows the regulator to provide a stable 5V output for a longer period as the battery voltage gradually decreases.
### 2.3 Thermal Protection
The L78L05ABU is equipped with thermal protection circuitry. When the device's temperature exceeds a certain threshold, the thermal protection mechanism kicks in to reduce the output current or even shut down the regulator temporarily. This protects the device from overheating, which could otherwise lead to permanent damage. In high - power applications or environments with poor heat dissipation, this feature ensures the long - term reliability of the regulator.
### 2.4 Short - Circuit Protection
Another important safety feature is short - circuit protection. In the event of a short circuit at the output, the regulator limits the current to a safe level, preventing excessive current flow that could damage the device or other components in the circuit. This protection mechanism enhances the overall robustness of the power supply system.
## 3. Electrical Specifications
### 3.1 Input Voltage Range
The L78L05ABU can typically accept an input voltage in the range of 7V to 25V. This wide input voltage range makes it suitable for a variety of power sources, such as AC - DC adapters, batteries, or other regulated power supplies. For example, it can be used in automotive applications where the battery voltage can vary from around 12V (when the engine is off) to 14V (when the engine is running).
### 3.2 Output Current
The regulator is capable of supplying a maximum output current of up to 100mA. This makes it suitable for powering small - to - medium - sized electronic components, such as sensors, small integrated circuits, and low - power microcontrollers.
### 3.3 Output Voltage Tolerance
The output voltage of the L78L05ABU has a tight tolerance, typically within ±2%. This high level of accuracy ensures that the connected electronic devices receive a consistent and reliable power supply, which is essential for their proper operation.
## 4. Package and Pin Configuration
### 4.1 Package Type
The L78L05ABU is commonly
Images for reference
SOT-89 SERIES
Image Preview
Image Preview