Texas Instruments LP38841T-1.2/NOPB

Overview

LP38841T-1.2/NOPB from Texas Instruments is a 0.8A ultra-low-dropout linear regulator with fixed 1.2V output, CMOS N-MOS pass transistor architecture, 75mV typical dropout at full load, ±1.5% initial output accuracy, and stable operation with ceramic output capacitors. It delivers core power to DSPs and microcontrollers in space-constrained industrial and embedded systems where input-to-output differential is minimal.

For engineers reviewing the LP38841T-1.2/NOPB datasheet, LP38841T-1.2/NOPB pinout, LP38841T-1.2/NOPB application, or LP38841T-1.2/NOPB equivalent, this page provides verified technical context, package-specific thermal behavior, real-world stability requirements for ceramic vs. tantalum capacitors, and validated alternative options for 1.2V LDO replacement in high-current post-regulation scenarios.

Technical Context

The LP38841T-1.2/NOPB uses a dual-rail architecture: VIN supplies load current while VBIAS (4.5–5.5V) powers internal circuitry and drives the N-MOS gate, enabling operation with VIN as low as VOUT + 75mV. Its CMOS process yields 30nA shutdown current and low ground-pin current across load range.

Stability relies on external capacitor selection: ≥22µF ceramic or ≥4.7µF tantalum on VOUT, plus 10µF ceramic on VIN and 0.1µF on VBIAS. The TO-220 package has θ_J-A = 65°C/W without heatsink, requiring thermal derating above 0.8A at elevated ambient temperatures.

Key Specifications

Pinout & Package

LP38841T-1.2/NOPB is housed in a 5-lead TO-220 package (KC variant) with exposed tab electrically connected to GND. The tab serves as primary thermal path and must be soldered to ≥1 in² copper area for optimal θ_J-A.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 1.2V LDO applications.

Compared with LP38841T-1.2/NOPB, TPS7A4700RGWR trades 0.8A capability for ultra-low noise in low-power analog rails, while LT1965EDD#PBF eliminates the VBIAS dependency at the cost of higher minimum input voltage-making LP38841T-1.2/NOPB uniquely suited for 1.2V core regulation from 1.3V-class intermediate rails.

Availability

LP38841T-1.2/NOPB is available at Aetrix Electronics and suitable for ASIC core power, SMPS post-regulation, DSP/FPGA supply, and gaming console SoC applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LP38841T-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 connectivity technologies, with decades of expertise in power management IC design and manufacturing.

The LP38841T-1.2/NOPB belongs to TI's ultra-low-dropout linear regulator product line, engineered specifically for high-current, low-noise core voltage regulation in space- and thermally-constrained digital systems.

FAQ

What is the minimum input voltage required for LP38841T-1.2/NOPB to maintain regulation?

The LP38841T-1.2/NOPB requires a minimum input-to-output differential of 75mV at 0.8A load, meaning VIN must be ≥1.275V to sustain 1.2V output regulation. This ultra-low dropout enables direct use with 1.5V or 1.8V intermediate rails, provided VBIAS remains within 4.5–5.5V. Below this differential, output voltage collapses nonlinearly.

Can LP38841T-1.2/NOPB operate without an external VBIAS supply?

No-LP38841T-1.2/NOPB requires an external 4.5–5.5V VBIAS rail to power its internal circuitry and drive the N-MOS gate. Unlike single-supply LDOs, it cannot derive bias from VIN. Omitting VBIAS prevents startup and causes immediate output failure, even if VIN is within specification.

What output capacitor types and values are mandatory for stable operation of LP38841T-1.2/NOPB?

LP38841T-1.2/NOPB requires either ≥22µF X5R/X7R ceramic or ≥4.7µF solid tantalum on the OUTPUT pin. Z5U/Y5V ceramics are prohibited due to severe capacitance loss with temperature and bias. The capacitor must be placed within 1cm of the OUTPUT pin and returned to clean analog ground to ensure loop stability and transient response.

How does thermal performance differ between the TO-220 and DDPAK packages for LP38841T-1.2/NOPB?

The LP38841T-1.2/NOPB in TO-220 (KC) has θ_J-A = 65°C/W with no heatsink, limiting usable power to ~0.92W at 25°C ambient. In contrast, the DDPAK variant achieves θ_J-A ≈ 35°C/W when soldered to ≥1 in² copper, enabling ~1.7W dissipation. For identical 0.8A loads at 1.275V input, TO-220 junction temperature rises ~50°C more than DDPAK under identical conditions.

Does LP38841T-1.2/NOPB include reverse-voltage or reverse-current protection?

No-the LP38841T-1.2/NOPB lacks built-in reverse-voltage or reverse-current protection. If output voltage exceeds input (e.g., during hot-swap or backup-battery scenarios), current flows backward through the N-MOS pass device, potentially damaging upstream circuitry. External Schottky diodes or ideal diode controllers are required for such fault conditions.