Texas Instruments LP3963ESX-2.5/NOPB

Overview

LP3963ESX-2.5/NOPB from Texas Instruments is a 3A ultra-low-dropout linear regulator with fixed 2.5V output, designed for high-current microprocessor and DSP power supply rails. It delivers ±1.5% output voltage accuracy at room temperature, supports 2.5V–7.0V input range, achieves 800mV dropout at 3A load, and integrates an error flag for output monitoring.

For engineers reviewing the LP3963ESX-2.5/NOPB datasheet, LP3963ESX-2.5/NOPB pinout, LP3963ESX-2.5/NOPB application, or LP3963ESX-2.5/NOPB equivalent, key selection criteria include dropout performance under 3A load, thermal shutdown behavior at 165°C, error flag threshold (−10% VOUT), ground current stability (6mA at 3A), and compatibility with 33µF/0.2–5Ω output capacitor requirements.

Technical Context

The LP3963ESX-2.5/NOPB uses a CMOS-based PMOS pass element with 240mΩ typical R_DS(on), enabling ultra-low dropout operation independent of load current. Its error flag circuitry monitors regulated output voltage with 10% undervoltage threshold and 5% hysteresis, asserting low when V_OUT falls below nominal by ≥10%.

It operates across −40°C to +125°C junction temperature, features overcurrent and thermal shutdown protection (165°C trip, 10°C hysteresis), and requires external 68µF minimum input capacitance (ESR ≤100mΩ) and 33µF output capacitance (ESR 0.2–5Ω) for loop stability.

Key Specifications

Pinout & Package

LP3963ESX-2.5/NOPB is packaged in DDPAK/TO-263-5 (surface-mount) with exposed thermal pad. This thermally enhanced package enables high-power dissipation without external heatsink under moderate ambient conditions.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP3963ESX-2.5/NOPB, TPS75725KTTT offers lower dropout and higher ripple rejection but omits fault signaling, while LT1963AES-2.5 provides significantly lower noise and smaller size at half the current capacity-neither matches the combination of 3A delivery, error flag, and wide-temp operation in the LP3963ESX-2.5/NOPB.

Availability

LP3963ESX-2.5/NOPB is available at Aetrix Electronics and suitable for microprocessor core supplies, GTL bus terminators, and DSP power rails requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for LP3963ESX-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

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 LP3963 series belongs to TI's ultra-low-dropout linear regulator product line, engineered specifically for high-current, low-voltage digital system power delivery where fast transient response and fault visibility are essential.

FAQ

What is the minimum input voltage required for LP3963ESX-2.5/NOPB to regulate at full 3A load?

The LP3963ESX-2.5/NOPB requires VIN ≥ VOUT + VDROPOUT = 2.5V + 0.8V = 3.3V to maintain regulation at 3A. Below this, output voltage collapses per the 800mV dropout specification. The device will operate down to 2.5V input only at very light loads where dropout is negligible.

Does LP3963ESX-2.5/NOPB require an external pull-up resistor on the ERROR pin?

Yes - the ERROR pin is open-drain and must be pulled high with a 10kΩ resistor to VIN or another valid logic-high source. If unused, the ERROR pin must be connected directly to GND per TI's datasheet guidance. Leaving it floating risks undefined behavior and potential noise susceptibility.

Can LP3963ESX-2.5/NOPB be used with ceramic output capacitors?

No - the LP3963ESX-2.5/NOPB requires output capacitor ESR between 0.2Ω and 5Ω for loop stability. Standard ceramic capacitors have ESR <10mΩ and will cause oscillation. Tantalum or aluminum polymer capacitors meeting the ESR range are required; ceramics may be added in parallel only if total effective ESR remains within spec.

How does the shutdown function behave in LP3963ESX-2.5/NOPB?

Driving the SD pin low disables the LP3963ESX-2.5/NOPB, reducing quiescent current to 15µA. During shutdown, the ERROR pin is disabled and invalid. The SD pin must be actively terminated - either with a 10kΩ pull-up to VIN or driven by a rail-to-rail CMOS output. Floating SD is not permitted.

What thermal considerations apply to LP3963ESX-2.5/NOPB in DDPAK/TO-263 package?

In the DDPAK/TO-263-5 package, LP3963ESX-2.5/NOPB has θ_JA = 60°C/W (with 0.5in², 1oz copper). At 3A and 3.3V input (0.8V dropout), power dissipation is ~2.4W - resulting in ~144°C junction rise above ambient. Heatsinking or airflow is mandatory for sustained 3A operation above 25°C ambient to stay within the +125°C max junction limit.