Texas Instruments LP5952LCX-1.8/NOPB

Overview

LP5952LCX-1.8/NOPB from Texas Instruments is a dual-rail linear regulator designed for ultralow-voltage post-regulation in battery-powered systems, delivering a fixed 1.8 V output at up to 350 mA. It operates with two independent supply rails: VBATT (2.5–5.5 V) powers internal circuitry, while VIN (0.7–4.5 V) supplies the regulated output path. Its 100 µV_RMS output noise, ±1 mV line transient response, and 0.1 µA shutdown current make it suitable for powering sensitive RF or digital core logic in mobile handsets.

For engineers reviewing the LP5952LCX-1.8/NOPB datasheet, LP5952LCX-1.8/NOPB pinout, LP5952LCX-1.8/NOPB application, or LP5952LCX-1.8/NOPB equivalent, key selection considerations include dual-rail biasing constraints (VIN ≤ VBATT), dropout voltage under 350 mA load (≤150 mV), thermal shutdown threshold (165°C), and USON-6 package compatibility with space-constrained portable PCB layouts.

Technical Context

The LP5952LCX-1.8/NOPB implements an NFET-based pass device with integrated thermal-overload, overcurrent, and undervoltage protection. Its dual-supply architecture separates bias (VBATT) from power delivery (VIN), enabling stable regulation even when VIN originates from a DC-DC converter's output - a configuration where VIN ramps slower than VBATT, eliminating sequencing concerns.

It features fast turn-on (70–150 µs startup time), no-load stability for keep-alive circuits, and reverse-current protection via body-diode current limiting (≤50 mA). The device maintains ±15 mV load transient response across 0–300 mA steps with di/dt = 300 mA/µs, and achieves >90 dB PSRR at 100 Hz on the VIN rail.

Key Specifications

Pinout & Package

LP5952LCX-1.8/NOPB is packaged in a 2.00 mm × 2.00 mm, 6-pin USON (NKH) package with wettable flanks for automated optical inspection. The package has no exposed thermal pad and uses a standard JEDEC MO-229 footprint.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-rail linear regulator applications.

Compared with TPL7407LPGQ1 and TPS7A1633DRBR, the LP5952LCX-1.8/NOPB uniquely supports dual-rail biasing, delivers 350 mA at 1.8 V with <130 mV dropout, and integrates thermal hysteresis and reverse-current limiting - making it the only option among the three qualified for post-regulation in Li-Ion-powered portable electronics.

Availability

LP5952LCX-1.8/NOPB is available at Aetrix Electronics and suitable for mobile handsets, wearable sensor hubs, portable medical instruments, and industrial handheld scanners requiring stable component supply across extended production lifecycles.

Supply support for LP5952LCX-1.8/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 and embedded processing technologies with broad automotive, industrial, and personal electronics reach.

The LP5952LCX-1.8/NOPB belongs to TI's precision dual-rail LDO family, engineered specifically for ultralow-voltage post-regulation in battery-powered portable devices where supply sequencing, noise, and efficiency at light loads are critical.

FAQ

What is the maximum allowable voltage difference between VBATT and VIN for LP5952LCX-1.8/NOPB?

The LP5952LCX-1.8/NOPB requires VIN ≤ VBATT at all times. Absolute maximum ratings specify VBATT – VIN ≥ 0.2 V; exceeding this risks damage. In typical post-regulation use, VIN is derived from a DC-DC converter powered by VBATT, ensuring natural sequencing where VBATT rises before VIN. For independent supplies, design must guarantee VIN never exceeds VBATT - a hard constraint enforced by internal architecture, not a recommended operating condition.

Can LP5952LCX-1.8/NOPB operate with no output load?

Yes, LP5952LCX-1.8/NOPB remains stable and in regulation with zero output load - a feature explicitly verified in the datasheet under "No-Load Stability." This behavior is critical for applications like CMOS RAM keep-alive circuits or always-on sensor monitors where the output may be disconnected or idle for extended periods without compromising regulation or causing oscillation.

What is the minimum output capacitance required for stable operation of LP5952LCX-1.8/NOPB?

LP5952LCX-1.8/NOPB requires a minimum 1.5 µF ceramic output capacitor (X7R dielectric, ≤300 mΩ ESR) for guaranteed stability across temperature and load. The datasheet recommends 2.2 µF as the typical value, and specifies that capacitance must remain ≥1.5 µF under worst-case conditions including DC bias and temperature drift. Using less than 1.5 µF risks instability, especially under dynamic load transitions.

Does LP5952LCX-1.8/NOPB support reverse current protection without external components?

LP5952LCX-1.8/NOPB provides limited reverse current protection via its internal NFET body diode, which safely conducts up to 50 mA from OUT to IN if the output is pulled above the input. Beyond 50 mA, an external Schottky diode (cathode on VIN, anode on VOUT) is mandatory. No additional components are needed for forward operation or for reverse currents ≤50 mA - a design feature confirmed in Section 7.3.6 of the official datasheet.

What is the thermal shutdown behavior of LP5952LCX-1.8/NOPB under continuous overload?

Under continuous thermal overload, LP5952LCX-1.8/NOPB activates thermal shutdown at TJ ≈ 165°C (typical), turning off the NFET pass device. It remains latched off until junction temperature falls by ~20°C (hysteresis), then automatically recovers. This results in pulsed output voltage during sustained overload - a self-protecting behavior documented in Section 6.9 and Figure 2 of the datasheet. Continuous operation above 125°C junction temperature is not recommended for reliability.