Texas Instruments LP3893ESX-1.2/NOPB

Overview

LP3893ESX-1.2/NOPB from Texas Instruments is a 3A ultra-low-dropout linear regulator with 1.2V fixed output, fabricated on CMOS process using an N-MOS pass transistor. It features 270 mV typical dropout at 3A, 1.5% output accuracy at 25°C, 60 nA shutdown current, and operates across −40°C to +125°C junction temperature. It powers microprocessor core voltages and DSP supplies where fast transient response and low quiescent current are critical.

For engineers reviewing the LP3893ESX-1.2/NOPB datasheet, LP3893ESX-1.2/NOPB pinout, LP3893ESX-1.2/NOPB application, or LP3893ESX-1.2/NOPB equivalent, key selection criteria include dropout voltage at full load, bias rail dependency (4.5–6V VBIAS), thermal derating in DDPAK/TO-263 package, and mandatory 10 µF minimum output capacitance with ESR constraints for stability.

Technical Context

The LP3893ESX-1.2/NOPB employs a CMOS-based architecture with separate VIN and VBIAS inputs: VIN supplies power to the load, while VBIAS (4.5–6V) drives the gate of the N-MOS pass transistor-enabling operation at ultra-low input-to-output differentials. This dual-rail design decouples gate drive from power path, eliminating bipolar-style ground current scaling with load.

Its fast transient response stems from wide bandwidth enabled by the N-MOS pass device and internal compensation optimized for ≥10 µF tantalum output capacitors with ESR between 0.01 Ω and 1 Ω. Built-in over-temperature and over-current protection ensure fault robustness without external circuitry.

Key Specifications

Pinout & Package

LP3893ESX-1.2/NOPB is housed in a 5-pin DDPAK/TO-263 (KTT) thermally enhanced surface-mount package with exposed thermal pad soldered to PCB copper plane for heat dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-dropout linear regulator applications.

Compared with TPS7A8300RGRT and LT3080IMSE#PBF, LP3893ESX-1.2/NOPB offers the lowest cost path for fixed 1.2 V/3 A with external VBIAS flexibility, while requiring careful ESR-controlled output capacitance and PCB copper thermal design-making it optimal for cost-sensitive, thermally managed industrial and computing power rails.

Availability

LP3893ESX-1.2/NOPB is available at Aetrix Electronics and suitable for microprocessor core supplies, DSP power rails, SMPS post-regulators, server I/O voltage rails, and FPGA configuration power chains requiring stable component supply, long-term lifecycle support, and RoHS-exempt compliance for industrial deployment.

Supply support for LP3893ESX-1.2/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 power management ICs, with decades of expertise in high-reliability linear regulators and power solutions.

The LP3893ESX-1.2/NOPB belongs to TI's LP38xx ultra-low-dropout linear regulator family, engineered specifically for high-current, fast-transient applications in computing, communications, and industrial systems where precision, low noise, and thermal efficiency are essential.

FAQ

What is the minimum input voltage required for LP3893ESX-1.2/NOPB to regulate at 3A load?

The LP3893ESX-1.2/NOPB requires VIN ≥ (VOUT + VDO). With a typical dropout voltage of 270 mV at 3 A, the minimum VIN is 1.47 V. However, the recommended operating condition specifies VIN ≥ (VOUT + VDO) to 5.5 V, and absolute maximum VIN survival rating is 6 V. Always maintain ≥10 µF input capacitance for stability.

Does LP3893ESX-1.2/NOPB require an external VBIAS supply, and what happens if it's omitted?

Yes, LP3893ESX-1.2/NOPB requires an external 4.5–6 V VBIAS supply applied to Pin 4 to drive the N-MOS pass transistor gate. If omitted or below ~4 V, the under-voltage lockout circuit prevents regulator turn-on, and no output voltage will be generated-even if VIN is valid. The VBIAS rail must be independently sourced and bypassed with 0.1 µF ceramic capacitance.

Can ceramic capacitors be used for the output of LP3893ESX-1.2/NOPB?

No-ceramic capacitors alone are unsuitable for the LP3893ESX-1.2/NOPB output due to their extremely low ESR (<10 mΩ), which falls outside the stable region (0.01–1 Ω) shown in Figure 21. Tantalum is recommended; aluminum electrolytics may be used only above 10°C. Ceramic capacitance can be added up to 15% of the total tantalum value for high-frequency filtering, but not as the primary output capacitor.

What thermal design considerations apply to LP3893ESX-1.2/NOPB in its DDPAK/TO-263 package?

LP3893ESX-1.2/NOPB in DDPAK/TO-263 (KTT) achieves θJA ≈ 40°C/W when soldered to ≥1.5 in² copper plane. Power dissipation is PD = (VIN − 1.2 V) × IOUT + VIN × IGND. For 3 A at VIN = 2.5 V, PD ≈ 4.2 W; with TJmax = 125°C and TA = 70°C, allowable θJA ≤ 13.1°C/W-requiring substantial copper area or forced air cooling. Thermal vias under the exposed pad are strongly recommended.

Is LP3893ESX-1.2/NOPB pin-compatible with other variants in the LP3893 family?

Yes-LP3893ESX-1.2/NOPB shares identical 5-pin DDPAK/TO-263 (KTT) pinout and footprint with all LP3893 variants including LP3893ES-1.2/NOPB and adjustable versions like LP3893ES-ADJ/NOPB. All share same VIN, GND, VOUT, VBIAS, and S/D pin assignments and thermal pad layout, enabling direct PCB reuse across output voltage options.