Overview
The LDS3985M25R, produced by STMicroelectronics, is a very low drop and low noise BiCMOS linear voltage regulator. It provides up to 300 mA of output current from an input voltage range of 2.5 V to 6 V. This regulator is stable with ceramic and high-quality tantalum capacitors, making it suitable for low power applications and battery-powered systems. The ultra-low dropout voltage, low quiescent current, and low noise characteristics make it an ideal choice for mobile phones, battery-powered wireless systems, and portable information appliances. The device also features a shutdown logic control function, allowing parts of the board to be put in standby mode to reduce total power consumption.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Input Voltage | 2.5 to 6 | V |
| Output Voltage (nominal) | 2.5 | V |
| Output Current (nominal) | 0.3 | A |
| Dropout Voltage (typ. at 300 mA load) | 150 mV | mV |
| Quiescent Current (typ. at no load) | 85 µA | µA |
| Quiescent Current (typ. at 300 mA load) | 200 µA | µA |
| Output Noise Voltage (RMS over 10 Hz to 100 kHz) | 30 µV | µV |
| Supply Voltage Rejection (SVR) at 1 kHz | 55 dB | dB |
| Supply Voltage Rejection (SVR) at 10 kHz | 50 dB | dB |
| Operating Temperature Range | -40 to 125 °C | °C |
| Package | SOT23-5L |
Key Features
- Input voltage range from 2.5 V to 6 V
- Stable with low ESR ceramic capacitors
- Very low dropout voltage (150 mV typ. at 300 mA load, 0.4 mV typ. at 1 mA load)
- Very low quiescent current (85 µA typ. at no load, 200 µA typ. at 300 mA load; max. 1.5 µA in OFF mode)
- Guaranteed output current up to 300 mA
- Wide range of output voltages available on request: fixed from 1.25 V to 5 V with 100 mV step
- Fast turn-on time: typ. 240 µs
- Logic-controlled electronic shutdown
- Internal current and thermal limit
- Low output voltage noise: 30 µV RMS over 10 Hz to 100 kHz
- Temperature range: -40 °C to 125 °C (industrial grade), -40 °C to 85 °C (automotive grade)
Applications
The LDS3985M25R is typically used in:
- Mobile phones and other battery-powered wireless systems
- Portable information appliances
- Low power applications and battery-powered systems where low dropout voltage and low noise are critical
Q & A
- What is the input voltage range of the LDS3985M25R?
The input voltage range is from 2.5 V to 6 V.
- What is the typical dropout voltage of the LDS3985M25R at 300 mA load?
The typical dropout voltage is 150 mV at 300 mA load.
- What is the quiescent current of the LDS3985M25R at no load?
The quiescent current is typically 85 µA at no load.
- Does the LDS3985M25R have a shutdown function?
- What is the operating temperature range of the LDS3985M25R?
- What is the typical output noise voltage of the LDS3985M25R?
- What is the supply voltage rejection (SVR) of the LDS3985M25R at 1 kHz?
- What is the turn-on time of the LDS3985M25R?
- Is the LDS3985M25R available in different packages?
- What are the typical applications of the LDS3985M25R?
