The LM337 is a popular adjustable 3-terminal negative voltage regulator integrated circuit (IC). It's widely used in various electronic circuits to provide a stable and user-defined negative voltage output. Here's a breakdown of its key characteristics:
Type: Adjustable Negative Voltage Regulator
Function: Regulates the output voltage to a user-defined negative value (relative to ground) by adjusting external resistors.
Key Features:
Adjustable Output Voltage: Negative output voltage can be set from -1.25 volts (minimum) to -37 volts (maximum) using two external resistors.
High Output Current: Can deliver a maximum output current of 1.5 amperes (A), making it suitable for powering various electronic components.
Internal Current Limiting: Protects the IC from damage due to excessive current flow.
Thermal Overload Protection: Shuts down the regulator in case of overheating, preventing permanent damage.
Safe Area Compensation: Maintains stable operation even under varying input and output voltage conditions.
Simple to Use: Requires only a few external components for basic operation.
Benefits:
Versatility: Adjustable output voltage allows for powering a wide range of circuits requiring negative voltage supplies.
High Output Current: Can handle powering multiple components or circuits with its 1.5A current capability.
Protection Features: Built-in safeguards like current limiting and thermal overload protection enhance circuit reliability.
Simple Design: Easy to implement in circuits with minimal external components.
Applications:
The LM337 finds use in various applications requiring a regulated negative voltage supply. Here are some examples:
Negative Voltage Power Supplies: Creates a stable negative voltage rail for powering operational amplifiers, pre-amplifiers, and other circuits requiring negative voltage biasing.
Battery Chargers: Can be used in battery charging circuits where negative voltage is needed for specific battery chemistries.
Linear Voltage Regulators: Used in conjunction with positive voltage regulators (like the LM317) to create dual voltage supplies for electronic devices.
Adjustable LED Drivers: With proper current limiting resistors, it can be used to power LEDs requiring a specific negative voltage.
Active Filters: Provides a stable negative voltage for certain active filter designs.