Texas Instruments LP3965EMP-1.8/NOPB

Overview

LP3965EMP-1.8/NOPB from Texas Instruments is a 1.5A ultra-low-dropout linear regulator with fixed 1.8V output, designed for microprocessor core power delivery in space-constrained applications. It operates from 2.5V to 7.0V input, delivers ±1.5% output voltage accuracy at room temperature, achieves 38mV dropout at 150mA, and features remote sense capability for improved load regulation at point-of-load.

For engineers reviewing the LP3965EMP-1.8/NOPB datasheet, LP3965EMP-1.8/NOPB pinout, LP3965EMP-1.8/NOPB application, or LP3965EMP-1.8/NOPB equivalent, key selection criteria include dropout performance under 1.5A load, SENSE pin implementation for remote regulation, thermal shutdown behavior at 165°C, and compatibility with 33µF/0.2–5Ω ESR output capacitors.

Technical Context

The LP3965EMP-1.8/NOPB uses a CMOS-based PMOS pass element with 240mΩ typical R_DS(on), enabling ultra-low dropout operation independent of load current. Its internal error amplifier compares feedback from the SENSE pin (or VOUT when unused) against a precision bandgap reference, delivering fast transient response to step-load changes.

It integrates overtemperature protection (165°C shutdown with 10°C hysteresis), short-circuit current limiting (~4.5A), and a 15µA shutdown mode. The ERROR flag (open-drain) asserts low when output drops >10% below nominal-active only when SD is high and regulator is enabled.

Key Specifications

Pinout & Package

SOT-223-5 surface-mount package with exposed thermal pad (pin 3 = VOUT, pin 4 = SENSE/ADJ, pin 5 = GND). Thermal resistance θ_JA = 90°C/W (0.5in² copper area), requiring PCB thermal relief for sustained 1.5A operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A4700RGWR and MCP1703T-1802E/MB, the LP3965EMP-1.8/NOPB uniquely combines 1.5A current, 38mV dropout, and SENSE functionality in a thermally enhanced SOT-223 package-making it irreplaceable for high-current, point-of-load regulated 1.8V core supplies.

Availability

LP3965EMP-1.8/NOPB is available at Aetrix Electronics and suitable for microprocessor core power, GTL bus termination, DSP supply regulation, SCSI termination, and battery-powered portable electronics requiring stable component supply and long-term manufacturability.

Supply support for LP3965EMP-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 leader specializing in analog, embedded processing, and connectivity technologies, with decades of expertise in power management IC design and manufacturing.

The LP3965EMP-1.8/NOPB belongs to TI's ultra-low-dropout linear regulator family targeting high-efficiency, low-noise power delivery for microprocessors, DSPs, and high-speed digital interfaces in industrial and computing applications.

FAQ

What is the minimum input voltage required for LP3965EMP-1.8/NOPB to regulate 1.8V output?

The LP3965EMP-1.8/NOPB requires VIN ≥ VOUT + V_DROPOUT. At 1.5A load, dropout is 380mV, so minimum VIN is 2.18V. However, the absolute operating minimum is 2.5V per datasheet specifications - meaning LP3965EMP-1.8/NOPB guarantees regulation only when VIN ≥ 2.5V, even if theoretical dropout allows lower.

Can the SENSE pin of LP3965EMP-1.8/NOPB be left unconnected?

No - the SENSE pin of LP3965EMP-1.8/NOPB must be connected either to the remote load point (for improved regulation) or directly to the VOUT pin (if local regulation suffices). Leaving it floating risks instability and violates the device's biasing requirements per TI's application notes.

Does LP3965EMP-1.8/NOPB support reverse current protection?

LP3965EMP-1.8/NOPB does not include active reverse current blocking. Its internal PMOS pass device contains a parasitic body diode that conducts if VOUT > VIN. The datasheet specifies this diode tolerates up to 200mA DC and 1A peak - so external reverse-blocking circuitry is required for bidirectional isolation.

What output capacitor ESR range is required for stable operation of LP3965EMP-1.8/NOPB?

LP3965EMP-1.8/NOPB requires an output capacitor with ESR between 0.2Ω and 5Ω for loop stability. Ceramic capacitors alone are unsuitable due to sub-10mΩ ESR; instead, use solid tantalum (ideal ESR ~1–2Ω) or hybrid configurations - e.g., 100µF tantalum + 3µF ceramic - verified across −40°C to +125°C.

How does the ERROR flag behave during shutdown of LP3965EMP-1.8/NOPB?

When the SD pin of LP3965EMP-1.8/NOPB is pulled low, the ERROR flag is forced invalid (high-impedance) to minimize power consumption. The flag resumes operation only after SD returns high and the regulator re-enables - confirming that LP3965EMP-1.8/NOPB's ERROR function is active exclusively during normal regulation mode.