Texas Instruments LP38500ATJ-ADJ/NOPB

Overview

LP38500ATJ-ADJ/NOPB from Texas Instruments is an adjustable 1.5-A ultra-low-dropout linear regulator with PMOS pass transistor, operating from 2.7 V to 5.5 V input and delivering 0.6 V to 5 V output. It features FlexCap compensation (stable with ceramic/tantalum/aluminum capacitors), 275 mV dropout at 1.5 A, ±1.5% V_ADJ accuracy (A grade), and 2 mA ground current at full load - used in FPGA core power, DSP supply rails, and precision ASIC voltage regulation.

For engineers reviewing the LP38500ATJ-ADJ/NOPB datasheet, LP38500ATJ-ADJ/NOPB pinout, LP38500ATJ-ADJ/NOPB application, or LP38500ATJ-ADJ/NOPB equivalent, key selection criteria include dropout performance at 1.5-A load, ESR-insensitive stability, thermal shutdown behavior (170°C), disable-mode compatibility (not supported on LP38500), and TO-263 package thermal resistance (R_θJA = 33.3°C/W).

Technical Context

The LP38500ATJ-ADJ/NOPB uses internal CMOS-based compensation to maintain ≥40° phase margin across all capacitor types and ESR values, eliminating external compensation requirements. Its feed-forward architecture enables fast load transient response - peak deviation of only 40 mV during 0.1 A → 1.5 A step at 0.5 A/µs slew rate.

It integrates overcurrent protection with 3.6 A peak current limit and thermal shutdown with 10°C hysteresis. Unlike the LP38502 variant, it lacks an ENABLE pin and relies solely on input voltage control for operation - making it suitable for fixed-enable systems where simplicity and minimal external components are prioritized.

Key Specifications

Pinout & Package

LP38500ATJ-ADJ/NOPB uses a 5-pin TO-263 (NDQ) package with exposed thermal pad (DAP), measuring 10.16 mm × 9.85 mm. The DAP must be soldered to a PCB copper pour tied to GND for effective heat dissipation (R_θJB = 16.9°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A4700RGWR and LT1963AES8-ADJ#PBF, LP38500ATJ-ADJ/NOPB uniquely combines 1.5-A output, ESR-insensitive stability, and 275-mV dropout in a TO-263 package - making it optimal for space-constrained, high-current, low-headroom applications where capacitor flexibility is essential.

Availability

LP38500ATJ-ADJ/NOPB is available at Aetrix Electronics and suitable for FPGA core power, DSP supply rails, and ASIC precision bias applications requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for LP38500ATJ-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 leader focused on analog and embedded processing technologies, serving industrial, automotive, and communications markets with high-reliability, application-optimized silicon.

The LP38500ATJ-ADJ/NOPB belongs to TI's FlexCap LDO family, designed specifically for high-current, low-noise, capacitor-flexible power delivery in space-constrained digital systems - emphasizing ease of design-in and reduced qualification overhead.

FAQ

What is the maximum output current specification for LP38500ATJ-ADJ/NOPB?

The LP38500ATJ-ADJ/NOPB is specified for 1.5 A DC output current under recommended operating conditions (T_J ≤ 125°C). Peak output current reaches 3.6 A before current limiting engages, and short-circuit current is rated at 3.7 A. Derating is required above 85°C ambient due to thermal limits - full 1.5-A capability assumes adequate PCB copper area for heat dissipation via the DAP.

Does LP38500ATJ-ADJ/NOPB support enable/disable functionality?

No, LP38500ATJ-ADJ/NOPB does not include an ENABLE pin. It operates continuously when input voltage is applied within 2.7 V–5.5 V. For applications requiring controlled startup or standby mode, the LP38502-ADJ variant (with EN pin) or external MOSFET switch on the input rail must be used instead. The LP38500ATJ-ADJ/NOPB pinout confirms absence of EN functionality - only IN, OUT, GND, ADJ, and N/C pins are present.

What capacitor types are validated for use with LP38500ATJ-ADJ/NOPB?

LP38500ATJ-ADJ/NOPB is validated for stable operation with ceramic (X5R/X7R dielectric), tantalum, and aluminum electrolytic capacitors - no ESR restrictions apply. Minimum 10 µF is required for both input and output. Ceramic capacitors are preferred for transient response and noise filtering; aluminum electrolytics may be used for bulk storage where cost or capacitance density is critical. Z5U/Y5F ceramics are explicitly excluded due to severe capacitance loss with temperature and bias voltage.

How does the thermal performance of LP38500ATJ-ADJ/NOPB compare to other TO-263 LDOs?

LP38500ATJ-ADJ/NOPB achieves R_θJA = 33.3°C/W on a standard JEDEC High-K board - significantly better than typical TO-263 LDOs (often >40°C/W) due to optimized DAP-to-PCB thermal interface. Its R_θJB = 16.9°C/W confirms efficient heat conduction into the board plane. This enables 1.5-A operation at up to 85°C ambient without heatsink, provided ≥4 cm² of 2-oz copper is connected to the DAP and thermally vias are used per TI layout guidelines.

What is the output voltage adjustment range and accuracy of LP38500ATJ-ADJ/NOPB?

LP38500ATJ-ADJ/NOPB supports adjustable output from 0.6 V to 5 V using an external resistor divider on the ADJ pin. V_ADJ is guaranteed ±1.5% at 25°C (A grade) and ±3.5% over full temperature/load range. The ADJ pin bias current is ≤750 nA, enabling high-resistance dividers to minimize quiescent current. Output accuracy is maintained independent of capacitor ESR, unlike conventional LDOs requiring precise ESR tuning.