Texas Instruments LP5900TL-1.5/NOPB

Overview

LP5900TL-1.5/NOPB from Texas Instruments is a 150-mA ultra-low-noise LDO regulator designed for RF and analog circuit power supply, featuring 1.5 V fixed output, 80 mV typical dropout at 150 mA, 6.5 μV_RMS output noise (10 Hz–100 kHz), and stable operation with only 0.47-μF ceramic input/output capacitors-no bypass capacitor required.

For engineers reviewing the LP5900TL-1.5/NOPB datasheet, LP5900TL-1.5/NOPB pinout, LP5900TL-1.5/NOPB application, or LP5900TL-1.5/NOPB equivalent, key selection criteria include low-noise performance in RF biasing, minimal external component count, thermal shutdown behavior at 160°C, and enable-controlled sequencing in portable battery-powered systems.

Technical Context

The LP5900TL-1.5/NOPB employs an internal bandgap reference filtered by an on-die RC network to suppress reference noise before amplification, eliminating need for external noise-bypass capacitors. Its error amplifier drives a PMOS pass transistor with 80 mV typical dropout at full 150 mA load.

Enable control uses a 1-MΩ internal pull-down resistor; logic-high threshold is 1.2 V (VIH), logic-low threshold is 0.4 V (VIL). Thermal protection activates at ~160°C junction temperature with ~20°C hysteresis, and the device remains stable with zero load current.

Key Specifications

Pinout & Package

LP5900TL-1.5/NOPB is packaged in a 4-pin DSBGA (YZR) with 1.108 mm × 1.083 mm body size and exposed thermal pad. The package requires soldering the thermal pad to PCB ground plane via thermal vias for reliable thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPL720F15-DBVR and MCP1700T-1502E/TT, LP5900TL-1.5/NOPB uniquely delivers 6.5 μV_RMS noise with 0.47-μF caps and 80 mV dropout-enabling RF-grade power in smallest-footprint portable designs where noise and input headroom are limiting factors.

Availability

LP5900TL-1.5/NOPB is available at Aetrix Electronics and suitable for cellular transceivers, Wi-Fi front-ends, portable audio codecs, and low-power sensor nodes requiring stable component supply with guaranteed long-term manufacturability.

Supply support for LP5900TL-1.5/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 headquartered in Dallas, Texas, specializing in analog, embedded processing, and digital signal processing technologies with broad industrial, automotive, and communications reach.

The LP5900 product line targets RF and analog subsystems in portable wireless devices, emphasizing ultra-low noise, minimal external components, and thermal robustness in ultra-thin packages.

FAQ

What is the minimum input voltage required for LP5900TL-1.5/NOPB to regulate 1.5 V output?

The LP5900TL-1.5/NOPB requires a minimum input voltage of 2.5 V to operate, but to maintain regulation at full 150 mA load, VIN must be ≥1.58 V (1.5 V + 80 mV dropout). Below 2.5 V, internal circuitry is not fully functional-even if dropout condition is met-so 2.5 V is the absolute minimum per recommended operating conditions. The LP5900TL-1.5/NOPB will not regulate correctly at inputs between 1.58 V and 2.5 V.

Can LP5900TL-1.5/NOPB be used without an output capacitor?

No, LP5900TL-1.5/NOPB requires a minimum 0.47-μF ceramic output capacitor for stability across all operating conditions, including no-load. The datasheet explicitly states that operation without C_OUT is not characterized or guaranteed. Using no output capacitor risks oscillation, poor transient response, and potential damage under load changes. The LP5900TL-1.5/NOPB is stable with 0.47 μF-not zero-and this capacitor must be X5R or X7R dielectric with ESR between 5 mΩ and 500 mΩ.

Does LP5900TL-1.5/NOPB require a noise-bypass capacitor?

No, LP5900TL-1.5/NOPB does not require a noise-bypass capacitor. Its internal design incorporates an RC filter on the bandgap reference to suppress noise before it reaches the error amplifier, achieving 6.5 μV_RMS output noise with only the standard 0.47-μF input and output ceramic capacitors. This eliminates the need for a separate 10-nF or 100-nF bypass capacitor typically used with other low-noise LDOs-reducing BOM count and PCB area. The LP5900TL-1.5/NOPB's architecture was specifically optimized for this capacitor-free noise performance.

What is the thermal pad connection requirement for LP5900TL-1.5/NOPB?

The thermal pad on the LP5900TL-1.5/NOPB DSBGA package must be soldered to a PCB copper area connected to ground potential-either directly to the GND net or to a dedicated thermal plane tied to GND. TI recommends using at least four 0.3-mm-diameter thermal vias under the pad to achieve R_θJB = 35.6°C/W. Connecting the thermal pad to any voltage other than GND-or leaving it floating-violates the absolute maximum ratings and may cause malfunction or premature failure. The LP5900TL-1.5/NOPB thermal pad is not electrically isolated.

How does the enable pin (EN) behave when left unconnected?

When the EN pin of LP5900TL-1.5/NOPB is left unconnected, its internal 1-MΩ pull-down resistor ensures the pin defaults to logic-low (<0.4 V), disabling the regulator output and reducing quiescent current to <1 μA. This fail-safe behavior prevents unintended power-up during assembly or handling. To enable the device, EN must be actively driven to ≥1.2 V with a low-impedance source-TI confirms that microcontroller GPIOs meeting these thresholds can drive EN directly. The LP5900TL-1.5/NOPB EN pin draws only 5.5 μA at 5.5 V, making it compatible with most digital outputs.