Texas Instruments LP5900TL-2.1/NOPB

Overview

LP5900TL-2.1/NOPB from Texas Instruments is a 150-mA ultra-low-noise LDO regulator designed for RF and analog circuits, delivering 2.1 V output with ±2% tolerance, 80 mV typical dropout at 150 mA, and 6.5 μV_RMS output noise (10 Hz–100 kHz). It operates from 2.5 V to 5.5 V input and requires only 0.47-μF ceramic input/output capacitors-no noise bypass capacitor needed-making it ideal for space-constrained cellular RF front-ends.

For engineers reviewing the LP5900TL-2.1/NOPB datasheet, LP5900TL-2.1/NOPB pinout, LP5900TL-2.1/NOPB application, or LP5900TL-2.1/NOPB equivalent, key selection criteria include low-noise performance in sensitive analog/RF rails, minimal external component count, thermal shutdown behavior at 160°C, and enable-controlled power sequencing in portable systems.

Technical Context

The LP5900TL-2.1/NOPB uses an internal low-pass RC filter on its reference voltage to suppress noise before buffering, eliminating need for external bypass capacitance. Its EN pin features a 1-MΩ internal pull-down resistor and logic-level thresholds (V_IL ≤ 0.4 V, V_IH ≥ 1.2 V) enabling direct interfacing with GPIOs.

It achieves 75 dB PSRR at 1 kHz and maintains stability with 0.47-μF X7R/X5R ceramic capacitors (ESR 5–500 mΩ), while supporting full operation across −40°C to +125°C junction temperature range and offering thermal shutdown with 20°C hysteresis.

Key Specifications

Pinout & Package

LP5900TL-2.1/NOPB is packaged in a 4-pin DSBGA (YZR) with 1.108 mm × 1.083 mm body size and exposed thermal pad on bottom. The package requires soldering the thermal pad to PCB ground plane via thermal vias for optimal thermal performance (R_θJB = 35.6°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with LP5900TL-2.1/NOPB, TPL7407LPGEDR trades RF-grade noise performance for multi-channel integration, while MCP1700T-2102E/TT offers marginally lower noise but omits thermal protection and requires larger output capacitance-making LP5900TL-2.1/NOPB the preferred choice for thermally constrained, noise-critical RF/analog designs.

Availability

LP5900TL-2.1/NOPB is available at Aetrix Electronics and suitable for cellular RF front-ends, wireless LAN transceivers, and portable medical sensors requiring stable component supply, low-noise regulation, and extended temperature operation.

Supply support for LP5900TL-2.1/NOPB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company specializing in analog and embedded processing technologies, with leadership in power management, signal chain, and high-reliability components.

The LP5900 product line was engineered specifically for RF and analog circuitry in portable electronics, emphasizing ultra-low noise, minimal external components, and robust thermal behavior in compact packages.

FAQ

What is the minimum input voltage required for LP5900TL-2.1/NOPB to regulate 2.1 V output?

The LP5900TL-2.1/NOPB requires a minimum input voltage of 2.5 V to operate, but to maintain regulation at full 150-mA load, the input must exceed 2.1 V by the dropout voltage-80 mV typical, so ≥2.18 V. For reliable operation across temperature and process variation, TI specifies 2.5 V as the absolute minimum recommended input voltage per datasheet Section 6.3.

Does LP5900TL-2.1/NOPB require an external noise bypass capacitor?

No, LP5900TL-2.1/NOPB does not require an external noise bypass capacitor. Its internal low-pass RC filter on the reference voltage suppresses noise before the output stage, enabling 6.5 μV_RMS noise performance with only 0.47-μF input and output ceramic capacitors-as confirmed in Sections 1, 3, and 7.3.3 of the SNVS358R datasheet.

What is the thermal shutdown behavior of LP5900TL-2.1/NOPB?

LP5900TL-2.1/NOPB activates thermal shutdown at approximately 160°C junction temperature and re-enables at ~140°C due to 20°C hysteresis. This cycling protects the device during sustained overload or inadequate PCB heat sinking, as detailed in Section 7.3.4 and Electrical Characteristics Table (T_SHUTDOWN = 160°C).

Can LP5900TL-2.1/NOPB be used with tantalum output capacitors?

While LP5900TL-2.1/NOPB can technically operate with tantalum output capacitors meeting 0.47–10 μF and 5–500 mΩ ESR, TI strongly recommends X7R/X5R ceramic capacitors due to their lower ESR, superior temperature stability, smaller footprint, and absence of surge-current failure modes-especially critical in battery-powered RF applications per Section 8.2.2.2.2.

What is the start-up time specification for LP5900TL-2.1/NOPB?

The LP5900TL-2.1/NOPB has a typical enable start-up time of 150 μs to reach 95% of nominal 2.1-V output, with a maximum of 300 μs across temperature and load conditions (Section 6.5, TRANSIENT CHARACTERISTICS). This timing assumes C_IN = C_OUT = 0.47 μF, V_EN = 1.2 V, and I_OUT = 1 mA per Figure 12 and Table specifications.