LP3985IBLX-285

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Overview

The LP3985IBLX-285/NOPB is a micropower, 150mA low-noise ultra low-dropout CMOS voltage regulator manufactured by Texas Instruments. It provides a fixed 2.85V output from a 2.5V to 6.0V input range. The device operates with a quiescent current of less than 1.5µA in shutdown mode and features fast turn-on time under 200µs. It maintains power supply rejection better than 50dB at 1kHz and delivers typical output noise of 30µVrms over a 10Hz to 100kHz bandwidth. The component is stable with small ceramic or high-quality tantalum output capacitors and functions within a junction temperature range of -40°C to +125°C.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Feature Summary

• Logic-controlled enable pin for active shutdown and power management
• Ultra-low dropout performance optimized for battery-powered systems
• Internal power-on circuit actively pre-charges bypass capacitor for fast start-up
• Stable operation with minimal external components including small ceramic capacitors

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Applications

• CDMA cellular handsets
• Wideband CDMA cellular handsets
• GSM cellular handsets
• Portable information appliances

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Procurement Notes

Verify the specific suffix 'BL' indicates the large bump micro SMD package configuration. Confirm the 'X' suffix denotes tape and reel packaging. Ensure the part number includes '/NOPB' if lead-free compliance is required. Cross-reference the manufacturer datasheet for exact thermal resistance values and absolute maximum ratings before finalizing procurement specifications.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Selection Notes

Select this regulator when board space is limited due to its miniature micro SMD footprint. Choose this model for applications requiring low noise and fast transient response without sacrificing load regulation. Consider the 2.85V fixed output option for direct compatibility with standard logic levels. Verify that the input voltage remains within the specified 2.5V to 6.0V range for optimal line regulation and dropout performance.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Part Context

This component belongs to the LP3985 series of micropower LDO regulators designed for portable wireless applications. The series offers various fixed output voltages and package options including SOT-23-5 and multiple micro SMD configurations. It is engineered to minimize application circuit area while delivering high performance in terms of noise and dropout voltage for battery-operated devices.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Replacement Considerations

LP3985IBL-285

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators FAQ

How does the LP3985 handle light sensitivity?

Exposing the micro SMD package to direct sunlight can cause misoperation. Red and infrared wavelengths are most detrimental, though fluorescent lighting has negligible effect.

What is the recommended output capacitor type?

A 1.0µF ceramic capacitor with X7R dielectric is recommended. It must have an ESR between 5mΩ and 500mΩ to ensure stability.