Texas Instruments LP38841T-1.5/NOPB

Overview

LP38841T-1.5/NOPB from Texas Instruments is a 1.5V, 0.8A ultra-low-dropout linear regulator with CMOS N-MOS pass transistor architecture, 75mV typical dropout at full load, ±1.5% initial output accuracy, and stable operation with ceramic output capacitors ≥22µF. It supports dual-rail operation (VIN for power path, VBIAS for gate drive) and delivers fast transient response for microcontroller core supplies.

For engineers reviewing the LP38841T-1.5/NOPB datasheet, LP38841T-1.5/NOPB pinout, LP38841T-1.5/NOPB application, or LP38841T-1.5/NOPB equivalent, key selection criteria include its 5-pin TO-220 package, 30nA shutdown current, 1.5V fixed output, bias voltage requirement (4.5–5.5V), and thermal performance with θ_J-A = 65°C/W (no heatsink).

Technical Context

The LP38841T-1.5/NOPB employs a CMOS-based N-MOS pass transistor controlled by an external VBIAS rail (4.5–5.5V), enabling ultra-low dropout operation even when VIN is only ~100mV above VOUT. Its loop stability is achieved via internal compensation optimized for ≥22µF ceramic or ≥4.7µF tantalum output capacitance.

It integrates overtemperature and overcurrent protection, features 30nA shutdown current when S/D is pulled low, and maintains 1.5% output accuracy across −40°C to +125°C junction temperature. The device draws only 2mA quiescent current from VBIAS and 30mA from VIN at full load.

Key Specifications

Pinout & Package

LP38841T-1.5/NOPB uses a 5-pin TO-220 (KC) package with exposed tab tied to GND. Pin 1 is INPUT, Pin 2 is GND, Pin 3 is OUTPUT, Pin 4 is BIAS, Pin 5 is SHUTDOWN (S/D). The metal tab serves as thermal path and electrical ground connection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TSS721AIDR and TPS7A4701RGWR, LP38841T-1.5/NOPB uniquely delivers 75mV dropout with ceramic stability and dual-rail control-making it optimal for space-constrained, low-VIN, high-accuracy 1.5V applications where bias voltage is available.

Availability

LP38841T-1.5/NOPB is available at Aetrix Electronics and suitable for ASIC power supplies, server core/I/O rails, and DSP/FPGA I/O voltage regulation requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LP38841T-1.5/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 power management ICs, with decades of expertise in high-reliability linear regulators and power solutions.

The LP38841T-1.5/NOPB belongs to TI's ultra-low-dropout LDO family designed specifically for high-current, low-noise, ceramic-capacitor-stable regulation in computing, communications, and industrial infrastructure equipment.

FAQ

What is the minimum input voltage required for LP38841T-1.5/NOPB to maintain regulation?

The LP38841T-1.5/NOPB requires a minimum input voltage of VOUT + VDO = 1.5V + 0.075V = 1.575V (typical) at 0.8A load. Under worst-case conditions (max VDO = 120mV), VIN must be ≥1.62V. This ultra-low dropout enables operation from tightly regulated intermediate rails or aging batteries.

Can LP38841T-1.5/NOPB operate without an external VBIAS supply?

No. LP38841T-1.5/NOPB requires a dedicated 4.5–5.5V VBIAS supply on Pin 4 to drive the N-MOS gate. Without VBIAS, the device cannot regulate. If a single supply is preferred, consider P-MOS LDOs like TPS7A4701RGWR-but they lack the 75mV dropout of LP38841T-1.5/NOPB.

What output capacitor is required for stable operation of LP38841T-1.5/NOPB?

LP38841T-1.5/NOPB requires ≥22µF X7R or X5R ceramic output capacitance placed within 1 cm of Pin 3 (OUTPUT) and returned to clean analog ground. Tantalum capacitors ≥4.7µF may be used but offer slower transient response and higher ESR.

Does LP38841T-1.5/NOPB include thermal protection?

Yes. LP38841T-1.5/NOPB integrates thermal shutdown that activates when junction temperature exceeds +150°C. Recovery occurs automatically once temperature falls below the hysteresis threshold. This protects the device during sustained overload or inadequate heatsinking.

What is the shutdown behavior of LP38841T-1.5/NOPB?

When the SHUTDOWN (S/D) pin (Pin 5) is pulled low (<0.7V), LP38841T-1.5/NOPB disables its output and reduces total quiescent current to 30nA typical. The output remains high-impedance; no reverse current flows. Pull S/D to VBIAS to enable normal operation.