Texas Instruments LP3964ES-3.3/NOPB

Overview

LP3964ES-3.3/NOPB from Texas Instruments is a fixed-output 3.3 V, 800-mA ultra-low-dropout linear regulator in SOT-223 package, featuring 24 mV dropout at 80 mA and 240 mV at 800 mA, ±1.5% output voltage accuracy, and remote sense (SENSE) capability for improved load regulation in distributed power systems.

For engineers reviewing the LP3964ES-3.3/NOPB datasheet, LP3964ES-3.3/NOPB pinout, LP3964ES-3.3/NOPB application, or LP3964ES-3.3/NOPB equivalent, key selection criteria include dropout performance under 800-mA load, thermal behavior in SOT-223, SENSE pin implementation for PCB layout, and compatibility with low-ESR tantalum output capacitors (0.2–5 Ω).

Technical Context

The LP3964ES-3.3/NOPB uses a PMOS pass element with 240 mΩ typical R_DS(on), enabling ultra-low dropout operation down to 24 mV at light load. Its CMOS-based control circuit maintains low quiescent current (15 µA in shutdown) independent of load, and supports fast transient response via internal compensation optimized for 33 µF minimum output capacitance.

Unlike the LP3961, this variant replaces the ERROR flag with a SENSE pin-internally connected to the error amplifier's feedback node-to enable remote voltage sensing at the load point. Shutdown is controlled by a CMOS-compatible SD input requiring external 10-kΩ pullup when active, with 1 nA input leakage.

Key Specifications

Pinout & Package

SOT-223 (5-pin) package: 6.50 mm × 3.56 mm body, exposed thermal pad on bottom, rated for 65.2°C/W junction-to-ambient thermal resistance (R_θJA) with standard JEDEC 2S2P layout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP3964ES-3.3/NOPB, TSS721AIDR offers smaller footprint but sacrifices remote sensing and dropout performance, while TPS7A4701RGWR delivers higher current and flexibility at the cost of added design overhead and non-pin-compatibility.

Availability

LP3964ES-3.3/NOPB is available at Aetrix Electronics and suitable for microprocessor core power, GTL+/SSTL bus termination, and battery-powered instrumentation requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for LP3964ES-3.3/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 company specializing in analog and embedded processing technologies, with leadership in power management ICs for industrial, automotive, and communications markets.

The LP396x series was designed specifically for ultra-low-dropout, high-accuracy linear regulation in noise-sensitive digital systems-targeting applications where fast load transients, remote sensing, and thermal robustness are essential.

FAQ

What is the minimum input voltage required for LP3964ES-3.3/NOPB to regulate 3.3 V at 800 mA?

The LP3964ES-3.3/NOPB requires a minimum input voltage of 3.54 V (3.3 V + 240 mV dropout) to maintain regulation at 800 mA. Below this, output voltage drops nonlinearly; the datasheet specifies stable operation only when VIN ≥ VOUT + 0.35 V under all conditions. At lighter loads, dropout falls to 24 mV, allowing VIN as low as 3.324 V.

How should the SENSE pin be connected in LP3964ES-3.3/NOPB if remote sensing is not needed?

If remote sensing is not required, the SENSE pin of LP3964ES-3.3/NOPB must be connected directly to the OUT pin using a low-impedance trace-never left floating. This configures the device as a standard local-sense LDO. Leaving SENSE unconnected risks instability or incorrect regulation due to undefined feedback node voltage.

Can LP3964ES-3.3/NOPB operate without an input capacitor?

No. LP3964ES-3.3/NOPB requires a minimum 68 µF input capacitor with ESR <100 mΩ, placed within 1 cm of the IN and GND pins. Omitting it causes instability, oscillation, or failure to start-especially under high di/dt load steps-because the internal bias circuit draws directly from IN and demands low source impedance.

What output capacitor types are compatible with LP3964ES-3.3/NOPB?

LP3964ES-3.3/NOPB requires an output capacitor with 33 µF minimum capacitance and ESR between 0.2 Ω and 5 Ω. Solid tantalum capacitors are recommended; aluminum electrolytics may be used if ESR stays within range across temperature. Ceramic capacitors alone are unsuitable due to near-zero ESR, but up to 3 µF ceramic may be paralleled with a 100-µF tantalum if stability margins allow.

Does LP3964ES-3.3/NOPB provide reverse current protection?

LP3964ES-3.3/NOPB does not include active reverse current protection. Its internal PMOS pass device contains a parasitic body diode that conducts if V_OUT exceeds V_IN-allowing up to 200 mA continuous or 1 A peak reverse current. External reverse-blocking diodes or ideal diode controllers are required in back-powering scenarios.