LP3982-25
Adjustable output LDO with 500mA current capability for general purpose applications
Product Overview
Description
The LP3982-25 is an adjustable output LDO regulator capable of delivering up to 500mA output current. The output voltage can be set from 1.2V to 4.5V using external resistors, providing flexibility for various application requirements.
The device features a low quiescent current of 80μA and good PSRR of 60dB at 1kHz. The dropout voltage is 300mV at 500mA, allowing efficient operation with moderate input-output voltage differentials. The current limit and thermal shutdown protection ensure safe operation under fault conditions.
The LP3982-25 is available in a thermally enhanced SOT-89 package, providing better heat dissipation for higher current applications. It is ideal for general purpose power supply, post-regulation after DC-DC converters, and battery-powered equipment.
Product Series
LP
Primary Application
General purpose power supply
Key Features
- Adjustable 1.2V - 4.5V output
- 500mA maximum output current
- Low 80μA quiescent current
- 300mV dropout at 500mA
- 60dB PSRR at 1kHz
- Current limit protection
- Thermal shutdown protection
- Thermally enhanced SOT-89 package
Specifications
| Output Voltage | 1.2V - 4.5V (adjustable) |
|---|---|
| Output Current | 500mA max |
| Quiescent Current | 80μA (typical) |
| Dropout Voltage | 300mV @ 500mA |
| PSRR | 60dB @ 1kHz |
| Input Voltage Range | 2.5V - 6V |
| Load Regulation | ±1.5% |
| Line Regulation | ±0.3%/V |
| Operating Temperature | -40°C to +85°C |
| Package | SOT-89 |
| Output Noise | 50μVRMS |
Applications
General purpose power supply
Power conversion and supply
Post-regulation for DC-DC
Power conversion and supply
Battery-powered equipment
Battery and charging management
Industrial control systems
Industrial automation and control
Communication devices
Communication and interface
FAE Expert Insights
"The LP3982-25 is a versatile adjustable LDO that I recommend for general purpose applications. The adjustable output voltage is very useful when you need a non-standard voltage rail. I've used it to generate 2.5V for DDR memory, 1.5V for FPGA core, and various other voltages. The 500mA current capability is sufficient for most subsystems. The SOT-89 package provides better thermal performance than SOT-23, allowing higher current operation without overheating. One implementation tip: the feedback resistors should be placed close to the IC, and the feedback trace should be kept away from noisy signals. I typically use 1% resistors for good output voltage accuracy. The thermal performance is good - I've run it at 400mA continuous without issues in normal ambient conditions. Overall, a flexible and reliable LDO for various applications."
Adjustable output LDO with 500mA capability for flexible voltage rail generation
— Chen Wei, BeiLuo
Frequently Asked Questions
How do I set the output voltage of LP3982-25?
The output voltage is set using two external resistors forming a voltage divider. The formula is VOUT = 1.2V × (1 + R1/R2). For example, for 3.3V output with R2 = 10kΩ, R1 = 17.5kΩ. Use 1% tolerance resistors for good accuracy.
Use resistor divider formula VOUT = 1.2V × (1 + R1/R2); 1% resistors recommended.