7905 IC Fixed 5V Negative Voltage Regulator
The LM7905 is a three-terminal negative linear voltage regulator from the 79xx series, designed to supply a constant −5V DC output from a higher negative input voltage. It offers a reliable solution for powering circuits that require a negative voltage rail.
This regulator typically operates with input voltages from −7V to −20V, providing up to 1A output current when properly heat-sinked. Internally, it includes safety features such as thermal shutdown, current limiting, and short-circuit protection, ensuring durability and fault tolerance.
The LM7905 is commonly used alongside positive regulators like the 7805 to provide dual-polarity supplies for analog systems, audio amplifiers, operational amplifier circuits, and industrial control systems. Its compact packaging and minimal external components simplify integration into a wide range of designs.
Pin Configuration (TO-220 Package)
| Pin | Name | Description |
|---|---|---|
| 1 | Ground | Common ground |
| 2 | Input | Negative unregulated input |
| 3 | Output | Regulated −5V output |
Applications
Powers circuits that need a steady −5V supply.
Works in dual polarity analog and audio systems.
Provides negative voltage for op-amp biasing circuits.
Supplies audio amps with required negative rail voltage.
Supports industrial control systems with negative voltage needs.
Delivers clean power in embedded negative voltage designs.
Used in signal conditioning and processing hardware setups.
Key Features
Provides a stable −5V fixed output for circuits.
Supports continuous output current up to 1 ampere.
Operates with input voltages down to −20 volts.
Includes internal thermal shutdown for safe operation.
Protects against overloads with built-in current limiting.
Handles short circuits with automatic protective mechanisms.
Offered in standard TO-220 and compact packages.
Specifications Table
| Parameter | Value |
|---|---|
| Output Voltage | −5V ± 2% |
| Maximum Output Current | 1A (with heatsink) |
| Input Voltage Range | −7V to −20V |
| Dropout Voltage | ~2V ‘ |
| Line Regulation | 10 mV (typical) |
| Load Regulation | 50–100 mV |
| Quiescent Current | 5–8 mA |
| Ripple Rejection | 60–80 dB |
| Operating Temperature Range | 0°C to +125°C |
| Junction Temperature Max | +150°C |
| Storage Temperature Range | −65°C to +150°C |
| Package Options | TO-220, TO-92, DPAK, SOT-223 |
