LP2985AIM5-2.5

LP2985AIM5-2.5 Application Field and Working Principle

LP2985AIM5-2.5 is a low-dropout (LDO) linear regulator with a very low noise and high precision. It is from Texas Instruments’ ultra-small group of low noise and low-voltage linear voltage regulators. It is suited for a wide range of applications, such as for battery-powered portable electronic devices, telecom, and low-noise analog applications.

LP2985AIM5-2.5 is designed for low-voltage and low-dropout voltage operation. It contains an on-chip power MOSFET to reduce dropout voltage, along with reverse current and thermal shutdown protection functions. It also has a wide operating temperature range and low quiescent current.

Applications

• Battery-powered portable electronic devices
• Telecom
• Low-noise analog applications
• Microprocessor/microcontroller power supplies
• Sensor and actuator supplies

Advantages

• Very low noise and high precision
• On-chip power MOSFET design for further reduction of dropout voltage
• Integrated reverse current and thermal shutdown protection
• Wide operating temperature range and low quiescent current

Working Principle

The LP2985AIM5-2.5 is a monolithic CMOS device with an low-dropout voltage designed for low-voltage, low-dropout operation. The device is comprised of an error amplifier, a comparator, a current limit circuit, a thermal shutdown circuit, and a power MOSFET. The device utilizes a PMOS pass element to provide excellent line and load transient response characteristics.

The error amplifier compares the output voltage to an internal reference and provides an error signal that controls the current limit circuit, which limits the current through the pass element and prevents damaging operation. The thermal shutdown circuit shuts down the device when the temperature reaches too high a level, preventing damage to the device.

The operation of the LP2985AIM5-2.5 is simple and can be broken into five sections: error amplifier, output transistor, current limiter, output voltage stabilization and thermal shutdown.

The error amplifier compares the input voltage to the internal reference voltage, generating an error voltage. The output transistor is then activated by the error amplifier and drives current through a current limiter, which limits the current in order to prevent damage to the device. The current is then regulated by the output voltage stabilization circuit, ensuring a stable output voltage. Finally, the thermal shutdown circuit is engaged when the temperature of the device becomes too high, shutting down the device and preventing damage.

Conclusion

LP2985AIM5-2.5 is a low-dropout, low-noise linear voltage regulator from Texas Instruments’ ultra-small group of low noise and low-voltage linear voltage regulators. It is suited for a wide range of applications, such as for battery-powered portable electronic devices, telecom, and low-noise analog applications. The device is comprised of an error amplifier, a comparator, a current limit circuit, a thermal shutdown circuit, and a power MOSFET. Its operation is simple, giving the device excellent line and load transient response characteristics.