Texas Instruments LP5951MG-1.5

Overview

LP5951MG-1.5 from Texas Instruments is a micropower, 150-mA low-dropout CMOS voltage regulator in SC70-5 package, delivering fixed 1.5 V output with 250 mV dropout at 150 mA, 29 µA quiescent current, and ±2 mV line transient response - designed for battery-powered portable systems requiring stable low-voltage rail generation.

For engineers reviewing the LP5951MG-1.5 datasheet, LP5951MG-1.5 pinout, LP5951MG-1.5 application, or LP5951MG-1.5 equivalent, key selection criteria include shutdown current (<1 nA), thermal protection (160°C trip), PSRR (–60 dB @ 1 kHz), fast turnon time (30 µs), and compatibility with 1-µF ceramic output capacitors.

Technical Context

The LP5951MG-1.5 employs a PMOS pass transistor architecture enabling ultra-low quiescent current and inherent reverse-current blocking. Its internal bias generator and reference circuitry operate down to 1.8 V input, supporting direct Li-ion or multi-cell alkaline battery integration.

Enable control is active-high with logic thresholds of 0.4 V (max VIL) and 0.9 V (min VIH), ensuring robust interfacing with 1.8 V/3.3 V microcontrollers. Internal thermal shutdown engages at 160°C (typ.) with 20°C hysteresis, and short-circuit current limiting protects during fault conditions.

Key Specifications

Pinout & Package

LP5951MG-1.5 is housed in a 2.00 mm × 1.25 mm SC70-5 package with 0.65 mm pitch, optimized for space-constrained portable designs. Thermal resistance R_θJA = 276.7°C/W enables operation up to 125°C junction temperature with minimal PCB copper.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-quiescent-current LDO applications.

Compared with LP5951MG-1.5, TPL720F15 trades 50 mA output capability for marginal IQ reduction, while MCP1700T-1502E/MB sacrifices enable functionality, thermal protection, and dropout performance to achieve lower cost and smaller pin count - making LP5951MG-1.5 optimal for safety-aware, dynamically powered portable systems.

Availability

LP5951MG-1.5 is available at Aetrix Electronics and suitable for wearable electronics, medical diagnostics devices, and industrial IoT edge nodes requiring stable component supply, long-lifecycle support, and guaranteed traceability.

Supply support for LP5951MG-1.5 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 leader specializing in analog and embedded processing technologies, with decades of expertise in power management IC design and manufacturing.

The LP5951 product line delivers micropower, low-noise LDO regulators for portable and battery-critical applications - engineered to maximize runtime while maintaining precision regulation across wide temperature and load ranges.

FAQ

What is the minimum input voltage required for LP5951MG-1.5 to regulate 1.5 V output?

The LP5951MG-1.5 requires VIN ≥ (VOUT + VDO), where VDO is 200 mV typical at 150 mA for 1.5 V output. Thus, minimum functional input is 1.7 V. However, TI specifies 1.8 V as the absolute minimum recommended operating voltage to ensure full specification compliance across temperature and process variation. Below 1.8 V, regulation may degrade or cease.

Can LP5951MG-1.5 be used with a 0402-size 1-µF ceramic capacitor on the output?

Yes, LP5951MG-1.5 is explicitly designed to remain stable with 1-µF ceramic capacitors, including 0402 case sizes such as TDK C1005X5R1A105K. However, DC bias derating must be verified: at 1.5 V bias, most X5R/X7R 0402 caps retain ≥0.7 µF (the minimum specified), satisfying stability requirements per TI's Application Note SNVS345G Section 6.8.

Does LP5951MG-1.5 provide reverse current protection?

LP5951MG-1.5 incorporates a PMOS pass device with an inherent body diode. It blocks reverse current (VOUT → VIN) under normal operation but allows up to 50 mA if VOUT exceeds VIN. For higher reverse currents or strict backfeed prevention, an external Schottky diode from VOUT to VIN (cathode on VIN) is required - this is documented in Section 7.3.6 of the datasheet.

How does the EN pin behave during power-up when VIN ramps slowly?

The LP5951MG-1.5 EN pin has hysteresis-free logic thresholds: it enables when VEN ≥ 0.9 V and disables when VEN ≤ 0.4 V. During slow VIN ramp, if EN is tied to VIN, the device turns on once VIN reaches ~0.9 V - well before the 1.8 V minimum input requirement. This may cause premature, unstable regulation. TI recommends tying EN to VIN only after VIN exceeds 1.8 V, or using a dedicated supervisor circuit.

Is LP5951MG-1.5 qualified for automotive applications?

No, LP5951MG-1.5 is not AEC-Q100 qualified. Its specified operating junction temperature range is –40°C to +125°C, matching automotive ambient requirements, but TI does not list it in automotive-grade product folders or qualify it per AEC stress tests. For automotive use, consider TI's TLV700xx-Q1 or TPS7B67xx-Q1 series instead.