Texas Instruments LP38501TS-ADJ/NOPB

Overview

LP38501TS-ADJ/NOPB from Texas Instruments is an adjustable 3-A ultra-low-dropout linear regulator using a PMOS pass transistor, operating from 2.7 V to 5.5 V input and delivering 0.6 V to 5 V output with ±1.5% V_ADJ accuracy (A grade), 420 mV dropout at 3 A, and stable operation with any capacitor type including 10-µF ceramic. It serves as a primary voltage rail for low-voltage microprocessors in FPGA/ASIC power supplies.

For engineers reviewing the LP38501TS-ADJ/NOPB datasheet, LP38501TS-ADJ/NOPB pinout, LP38501TS-ADJ/NOPB application, or LP38501TS-ADJ/NOPB equivalent, key selection criteria include dropout voltage at full load, FlexCap compensation compatibility, EN pin control timing, thermal performance in DDPAK/TO-263, and ±1.5% output accuracy over temperature.

Technical Context

The LP38501TS-ADJ/NOPB implements a CMOS-based PMOS LDO architecture with internal feed-forward loop enhancement, enabling fast load transient response (±40 mV peak deviation at 0.1–3 A step with 10-µF ceramic). Its FlexCap compensation eliminates ESR dependency, supporting stable operation with ceramic, tantalum, or aluminum electrolytic output capacitors.

It integrates enable-controlled shutdown (25-nA quiescent current), overtemperature shutdown (170°C with 10°C hysteresis), and current limiting (6 A peak, 3.5 A short-circuit). The DAP thermal pad must be connected to ground for effective heat dissipation, with R_θJA = 41.8°C/W in KTT (DDPAK/TO-263) package.

Key Specifications

Pinout & Package

LP38501TS-ADJ/NOPB uses the KTT (DDPAK/TO-263-5) package: 10.16 mm × 8.42 mm body with exposed thermal pad (DAP) electrically tied to die backside and requiring PCB ground connection for thermal management.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A8300RGRT and LT3080IMSE#PBF, LP38501TS-ADJ/NOPB uniquely balances 3-A capability, FlexCap capacitor freedom, integrated EN control, and ±1.5% accuracy - making it optimal for space-constrained, multi-rail digital systems where design reuse and capacitor BOM simplification matter.

Availability

LP38501TS-ADJ/NOPB is available at Aetrix Electronics and suitable for FPGA core power supplies, ASIC I/O regulation, DSP analog-domain supplies, industrial SMPS post-regulation, and embedded microprocessor rails requiring stable component supply across production lifecycles.

Supply support for LP38501TS-ADJ/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 headquartered in Dallas, Texas, designing and manufacturing analog ICs, embedded processors, and power management solutions for industrial, automotive, and communications markets.

LP38501TS-ADJ/NOPB belongs to TI's FlexCap LDO family, engineered specifically for high-current, low-voltage digital loads where capacitor flexibility, fast transient response, and precision regulation are mandatory - not just desirable.

FAQ

What is the minimum output capacitor required for stable operation of LP38501TS-ADJ/NOPB?

The LP38501TS-ADJ/NOPB requires a minimum 10-µF output capacitor placed within 1 cm of the device. This value applies to ceramic, tantalum, or aluminum electrolytic types due to its FlexCap compensation architecture - no ESR minimum or maximum is specified. Larger values improve transient response but are not required for stability.

Does LP38501TS-ADJ/NOPB support reverse current protection?

LP38501TS-ADJ/NOPB does not include active reverse current blocking. Its internal PMOS pass transistor has a parasitic body diode that conducts if V_OUT exceeds V_IN; continuous reverse current is limited to 200 mA, with 1-A peak rating. For bidirectional isolation, an external Schottky diode or ideal diode controller is required.

How does the EN pin function on LP38501TS-ADJ/NOPB, and what drive strength is needed?

The EN pin on LP38501TS-ADJ/NOPB is an active-high logic input with VIH ≥1.4 V and VIL ≤0.65 V. It draws only 35 nA in either state, allowing direct interface with GPIOs or open-drain comparators. If unused, it must be tied to VIN via a 10-kΩ pullup - floating is prohibited per datasheet.

What thermal considerations apply to LP38501TS-ADJ/NOPB in the KTT (DDPAK/TO-263) package?

LP38501TS-ADJ/NOPB in KTT package has R_θJA = 41.8°C/W and requires the DAP thermal pad to be soldered to a solid GND copper pour. Junction temperature must stay below 125°C under load; at 3 A and 3.3-V input, power dissipation is ~1.26 W - resulting in ~53°C rise above ambient with proper layout, well within safe limits.

Is LP38501TS-ADJ/NOPB pin-compatible with LP38503TS-ADJ/NOPB?

No - LP38501TS-ADJ/NOPB includes an EN pin (Pin 1), while LP38503TS-ADJ/NOPB replaces Pin 1 with N/C. Their pinouts differ: LP38501 uses IN–EN–GND–OUT–ADJ; LP38503 uses IN–N/C–GND–OUT–ADJ. PCB layouts are not interchangeable without modification.