Texas Instruments LP3987ITLX-2.5/NOPB

Overview

LP3987ITLX-2.5/NOPB from National Semiconductor is a 150 mA fixed-output ultra-low-dropout CMOS LDO voltage regulator in a 5-bump micro SMD package, delivering 2.5 V output with ≤100 mV dropout at full load, 1 µA shutdown current, and 14 µA sleep-mode quiescent current-designed for battery-powered CDMA/GSM handsets and µP/DSP power supplies.

For engineers reviewing the LP3987ITLX-2.5/NOPB datasheet, LP3987ITLX-2.5/NOPB pinout, LP3987ITLX-2.5/NOPB application, or LP3987ITLX-2.5/NOPB equivalent, key selection criteria include guaranteed 150 mA output under 2.7–6.0 V input, sleep-mode current reduction to 14 µA, PSRR of 50 dB at 10 kHz, thermal/overcurrent protection, and compatibility with 1 µF ±20% ceramic output capacitors down to 5 mΩ ESR.

Technical Context

The LP3987ITLX-2.5/NOPB employs a CMOS pass transistor architecture enabling ultra-low dropout (≤100 mV @ 150 mA) and micropower operation. Its dual-control logic interface-VEN for enable/disable and MODE for active/sleep mode switching-supports dynamic power management in portable systems.

Stability is achieved with minimal external components: it operates reliably with 1 µF ceramic output capacitors (ESR 5–500 mΩ) and includes internal thermal shutdown (155°C trip), short-circuit current limiting (600 mA active / 28–43 mA sleep), and no-load regulation capability for SRAM backup applications.

Key Specifications

Pinout & Package

The LP3987ITLX-2.5/NOPB uses a 5-bump micro SMD package (NS Package Number TLA05), measuring 1.006 mm × 1.438 mm × 0.600 mm, with non-solder-mask-defined (NSMD) pads per AN-1112 mounting guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLS820B0LDV50 and TPS7A0525PDQNR, the LP3987ITLX-2.5/NOPB uniquely delivers 150 mA output with true two-state power management (active/sleep), sub-100 mV dropout, and micro SMD footprint - making it optimal for space-constrained, battery-sensitive cellular and portable applications where both peak current and standby efficiency matter.

Availability

LP3987ITLX-2.5/NOPB is available at Aetrix Electronics and suitable for CDMA/GSM handset designs, digital camera power architectures, and SRAM backup circuits requiring stable component supply, long-lifecycle availability, and consistent parametric performance across temperature extremes.

Supply support for LP3987ITLX-2.5/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

National Semiconductor was a U.S.-based semiconductor company acquired by Texas Instruments in 2011, known for precision analog ICs, power management solutions, and high-reliability interface products.

The LP3987ITLX-2.5/NOPB belongs to National's micropower LDO family, engineered specifically for battery-operated portable electronics demanding ultra-low quiescent current, minimal board space, and robust transient performance under dynamic load conditions.

FAQ

What is the maximum input voltage rating for the LP3987ITLX-2.5/NOPB?

The LP3987ITLX-2.5/NOPB has an absolute maximum input voltage (VIN) rating of 6.5 V, but its recommended operating range is 2.7 V to 6.0 V. Exceeding 6.5 V risks permanent damage. For reliable operation in battery-powered systems, VIN should remain ≥2.6 V to maintain regulation given the 100 mV dropout specification - ensuring the LP3987ITLX-2.5/NOPB continues delivering 2.5 V even as Li-ion cells discharge.

How does the sleep mode function differ from shutdown mode in the LP3987ITLX-2.5/NOPB?

In shutdown mode (VEN = 0 V), the LP3987ITLX-2.5/NOPB draws <1 µA and disables all output regulation. In sleep mode (MODE = 0 V, VEN = high), it maintains 2.5 V output but limits current to 3 mA and reduces quiescent current to 14 µA - enabling low-power subsystems like real-time clocks or memory retainers to remain active. The LP3987ITLX-2.5/NOPB thus supports three distinct states: active (150 mA), sleep (3 mA), and shutdown (<1 µA).

Can the LP3987ITLX-2.5/NOPB operate stably with a 1 µF ceramic output capacitor?

Yes - the LP3987ITLX-2.5/NOPB is explicitly characterized and guaranteed stable with a 1 µF ±20% ceramic output capacitor having ESR between 5 mΩ and 500 mΩ. This is confirmed in the datasheet's "Enhanced Stability" section and Electrical Characteristics table. Using X7R dielectric ensures capacitance retention across temperature; Z5U/Y5V types may lose >50% value at 85°C but still meet minimum 1 µF requirement at room temperature for many applications. The LP3987ITLX-2.5/NOPB does not require larger capacitors for basic stability.

What is the thermal shutdown threshold and recovery behavior of the LP3987ITLX-2.5/NOPB?

The LP3987ITLX-2.5/NOPB triggers thermal shutdown at a junction temperature of 155°C, disabling the pass transistor until the die cools below the hysteresis threshold (~125°C). This protects against sustained overload or inadequate PCB copper pour. Recovery is automatic and does not require cycling VEN or MODE. During normal operation, the device's θJA of 255°C/W means power dissipation must be limited - e.g., at 150 mA and 100 mV dropout, only 15 mW is dissipated, keeping junction temperature well within safe limits unless ambient exceeds 125°C. The LP3987ITLX-2.5/NOPB is rated for continuous operation up to +125°C junction temperature.

Is the LP3987ITLX-2.5/NOPB compatible with tantalum output capacitors?

Yes - the LP3987ITLX-2.5/NOPB is stable with high-quality tantalum output capacitors, provided they meet the 1 µF minimum value and 5–500 mΩ ESR range. However, tantalum capacitors exhibit higher ESR than ceramics (requiring larger values for same ESR), greater cost, and potential surge-current failure when connected directly to batteries. The datasheet recommends ceramic capacitors for size, cost, and reliability advantages. If using tantalum, verify manufacturer-rated surge current capability and derate ESR for −40°C operation (where ESR can double). The LP3987ITLX-2.5/NOPB's stability margin accommodates both technologies, but ceramic remains the preferred choice.