Texas Instruments LP5951MG-1.8

Overview

LP5951MG-1.8 from Texas Instruments is a micropower, 150-mA low-dropout CMOS voltage regulator in SC70-5 package, delivering a fixed 1.8 V output with 29 µA typical quiescent current, 250 mV dropout at 150 mA, and ±2 mV line transient response-designed for battery-powered portable electronics requiring stable low-voltage rail generation.

For engineers reviewing the LP5951MG-1.8 datasheet, LP5951MG-1.8 pinout, LP5951MG-1.8 application, or LP5951MG-1.8 equivalent, key selection criteria include shutdown current (<1 nA), PSRR (–60 dB at 1 kHz), thermal protection (160°C trip), enable logic thresholds (0.4 V/0.9 V), and compatibility with 1-µF ceramic output capacitors.

Technical Context

The LP5951MG-1.8 integrates a PMOS pass device with internal bias generator, overcurrent and thermal protection circuitry, and fast-turnon architecture enabling 30 µs startup. Its no-load stability supports RAM keep-alive applications without external load.

Enable control is active-high with VIH = 0.9 V and VIL = 0.4 V across –40°C to 125°C; the NC pin has no internal connection. Reverse current path exists via parasitic body diode, limiting output-to-input forward current to 50 mA unless externally clamped.

Key Specifications

Pinout & Package

LP5951MG-1.8 is housed in a 2.00 mm × 1.25 mm SC70-5 package with 0.65 mm 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 LP5951MG-1.8, TPS7A0518PDBVR offers lower dropout and quiescent current but uses a different pinout and lacks NC pin; TPL7407LPGQ is functionally unrelated-a driver IC, not a regulator-making it unsuitable as a direct alternative.

Availability

LP5951MG-1.8 is available at Aetrix Electronics and suitable for portable medical monitors, smart wearable sensor nodes, industrial IoT edge nodes, and low-power wireless MCU modules requiring stable component supply with long-term lifecycle assurance.

Supply support for LP5951MG-1.8 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 ICs for portable and industrial applications.

The LP5951 product line delivers micropower, low-noise LDOs for battery-powered systems-designed specifically for space-constrained, energy-sensitive applications like wearables, medical sensors, and IoT endpoints.

FAQ

What is the maximum input voltage rating for LP5951MG-1.8?

The absolute maximum input voltage (IN pin to GND) for LP5951MG-1.8 is 6.5 V. However, the recommended operating range is 1.8 V to 5.5 V per TI's SNVS345G datasheet. Exceeding 5.5 V may trigger internal protection or degrade reliability; sustained operation above 6.5 V risks permanent damage. Always maintain VIN within spec to ensure LP5951MG-1.8 functions reliably across its –40°C to 125°C junction temperature range.

Does LP5951MG-1.8 require an external pull-up resistor on the EN pin?

No, LP5951MG-1.8 does not require an external pull-up on the EN pin. The EN input has high impedance (<1 µA leakage), so it must be actively driven-either by a logic signal or tied directly to VIN for permanent enable. Leaving EN floating is prohibited and may cause erratic behavior. If system-level logic cannot guarantee valid VIH (≥0.9 V) or VIL (≤0.4 V), a weak pull-up to VIN (e.g., 100 kΩ) is acceptable but not mandatory; TI recommends direct connection for deterministic operation of LP5951MG-1.8.

Can LP5951MG-1.8 operate with a 0.47 µF output capacitor?

No-LP5951MG-1.8 is not guaranteed stable with 0.47 µF output capacitance. The datasheet specifies a minimum of 0.7 µF (including all tolerances and derating over temperature/bias), with 1 µF as the recommended nominal value. Using 0.47 µF risks oscillation, poor load transient response, or failure to regulate under varying conditions. For reliable LP5951MG-1.8 operation, use X7R/X5R ceramic capacitors ≥0.7 µF (e.g., 1 µF 0402 or 0603) with ESR between 3 mΩ and 300 mΩ.

What is the thermal shutdown hysteresis of LP5951MG-1.8?

The thermal shutdown hysteresis of LP5951MG-1.8 is 20°C. The device disables the PMOS pass element when junction temperature reaches 160°C (typical), then re-enables it once temperature falls to approximately 140°C. This hysteresis prevents rapid cycling during thermal overload and protects the die from cumulative thermal stress. During continuous overload, LP5951MG-1.8 enters pulsed output mode-critical for safeguarding both the regulator and downstream circuitry in sealed enclosures or high-ambient environments.

Is LP5951MG-1.8 compatible with ceramic capacitors having 10% tolerance?

Yes-LP5951MG-1.8 is compatible with 10% tolerance ceramic capacitors, provided the *minimum* capacitance (after accounting for tolerance, DC bias, and temperature effects) remains ≥0.7 µF. For example, a 1 µF ±10% X7R capacitor retains ≥0.9 µF at room temperature but may drop below 0.7 µF at high DC bias or temperature extremes. TI recommends verifying worst-case capacitance using manufacturer datasheets; LP5951MG-1.8's stability margin accommodates 10% tolerance when proper dielectric (X7R/X5R) and case size (e.g., 0603) are selected.