Texas Instruments LP5951MF-1.3

Overview

LP5951MF-1.3 from Texas Instruments is a micropower, 150-mA low-dropout CMOS voltage regulator with fixed 1.3 V output, 1.8–5.5 V input range, 29 µA typical quiescent current, and SC70-5 package. It delivers stable power to ultra-low-power digital ICs in battery-operated portable systems such as wearables and sensor nodes.

For engineers reviewing the LP5951MF-1.3 datasheet, LP5951MF-1.3 pinout, LP5951MF-1.3 application, or LP5951MF-1.3 equivalent, key selection criteria include dropout voltage at 150 mA (200 mV), shutdown current (<1 nA), load transient response (±50 mVpp), PSRR (–60 dB @ 1 kHz), and compatibility with 1-µF ceramic output capacitors.

Technical Context

The LP5951MF-1.3 employs a PMOS pass device architecture enabling ultra-low quiescent current and fast turn-on (30 µs typ.). Its internal bias generator and reference circuitry are optimized for operation down to 1.8 V input, supporting direct regulation from single-cell Li-ion or Li-polymer batteries.

It integrates thermal overload protection (trip at 160°C, hysteresis 20°C) and short-circuit current limiting. The EN pin provides active-high logic control with VIH = 0.9 V and VIL = 0.4 V over –40°C to 125°C, ensuring reliable enable/disable across industrial temperature ranges.

Key Specifications

Pinout & Package

LP5951MF-1.3 is housed in a 2.00 mm × 1.25 mm SC70-5 surface-mount package with 0.65 mm lead pitch, optimized for space-constrained portable PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout regulator applications.

Compared with TPL7407LPGQ and MCP1703T-1302E/MB, the LP5951MF-1.3 uniquely balances 1.8-V minimum input, 200-mV dropout, and 29-µA IQ in SC70-5-making it optimal for space- and energy-constrained 1.3-V systems where input voltage headroom is minimal.

Availability

LP5951MF-1.3 is available at Aetrix Electronics and suitable for wearable electronics, IoT sensor nodes, industrial PLC I/O modules, and medical handheld diagnostics requiring stable component supply with consistent parametric performance across temperature and production lots.

Supply support for LP5951MF-1.3 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 delivering analog and embedded processing solutions, with leadership in power management, signal chain, and microcontroller technologies.

The LP5951MF-1.3 belongs to TI's LP59xx family of micropower LDOs, engineered specifically for battery-powered portable systems demanding ultra-low IQ, small footprint, and robust transient performance under light-to-moderate loads.

FAQ

What is the minimum input voltage required for LP5951MF-1.3 to regulate at 1.3 V?

The LP5951MF-1.3 requires a minimum input voltage of 1.8 V for internal circuit functionality. To maintain regulation at 1.3 V output, VIN must be ≥(1.3 V + VDO). With a typical dropout of 200 mV at 150 mA, the practical minimum input is 1.5 V-but the device will not operate below 1.8 V per absolute ratings. Always ensure VIN ≥1.8 V and ≥(VOUT + VDO) for stable regulation.

Can LP5951MF-1.3 be used with a 0402-size 1-µF ceramic capacitor?

Yes, LP5951MF-1.3 supports 1-µF ceramic output capacitors-including 0402 case sizes-but capacitor DC bias derating must be verified. As shown in TI's Figure 11, a 0402 X5R 1-µF cap may fall below 0.7 µF at 1.3 V bias, violating the 0.7 µF minimum requirement. Use 0603 or larger, or select X7R dielectric with tighter bias stability, to guarantee compliance across voltage and temperature.

Does LP5951MF-1.3 require an input capacitor, and what value is recommended?

Yes, LP5951MF-1.3 requires an input capacitor for stability. TI recommends a 1-µF ceramic capacitor placed ≤1 cm from the IN pin and returned to clean analog ground. Larger values (e.g., 2.2 µF or 4.7 µF) are acceptable and improve line transient response. Tantalum or film types may be used, but ceramic is preferred for lowest ESR and smallest footprint.

What happens to the output when the EN pin is left floating on LP5951MF-1.3?

Leaving the EN pin floating on LP5951MF-1.3 risks unpredictable operation due to noise coupling or internal leakage, potentially causing erratic enable/disable behavior. TI explicitly states the EN pin "should not be left floating." For permanent ON operation, tie EN directly to VIN. For controlled shutdown, drive EN with a clean logic signal meeting VIH ≥0.9 V and VIL ≤0.4 V.

Is LP5951MF-1.3 compatible with lead-free reflow soldering processes?

Yes, LP5951MF-1.3 in SC70-5 package is rated for Pb-free reflow with a peak temperature of 260°C for 10–20 seconds, per JEDEC J-STD-020. Its moisture sensitivity level (MSL) is 1, meaning unlimited floor life at ≤30°C/85% RH-no baking required prior to assembly. Thermal metrics (e.g., RθJA = 276.7°C/W) assume standard JEDEC-compliant board layout.