Texas Instruments LP38513S-1.8/NOPB

Overview

LP38513S-1.8/NOPB from Texas Instruments is a 3-A ultra-low-dropout linear regulator with fixed 1.8-V output, operating from 2.25 V to 5.5 V input. It features 425 mV typical dropout at 3 A, ±2.6% output voltage accuracy over −40°C to +125°C, and an open-drain ERROR flag indicating >15% VOUT deviation. It powers low-voltage microprocessors requiring fast transient response and ceramic-capacitor stability.

For engineers reviewing the LP38513S-1.8/NOPB datasheet, LP38513S-1.8/NOPB pinout, LP38513S-1.8/NOPB application, or LP38513S-1.8/NOPB equivalent, key selection criteria include dropout voltage under full load, ground current vs. load, ERROR flag threshold hysteresis, thermal performance in DDPAK/TO-263, and compatibility with 10-µF ceramic input/output capacitors.

Technical Context

The LP38513S-1.8/NOPB uses a PMOS pass transistor on a CMOS process, enabling load-independent quiescent current and fast line/load transient response. Its ERROR flag operates with 85% nominal VOUT threshold and ~4% hysteresis, and is forced low during EN deactivation.

It integrates overcurrent and thermal shutdown protection, with short-circuit limiting cycling into thermal regulation. The enable threshold is 0.85 V typical with no hysteresis, and the EN pin requires external biasing-no internal pullup/pulldown.

Key Specifications

Pinout & Package

LP38513S-1.8/NOPB is packaged in a 5-pin DDPAK/TO-263 (KTT) with exposed thermal tab internally connected to Pin 3 (GND). The tab must be soldered to a PCB copper pour for thermal management.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPL7407LADGQR and TPS7A8300RGRT, LP38513S-1.8/NOPB uniquely balances 3-A capability, 425-mV dropout, and ceramic-stability in a thermally robust DDPAK package - making it optimal for space-constrained, high-current 1.8-V microprocessor supplies where input voltage may dip near 2.25 V.

Availability

LP38513S-1.8/NOPB is available at Aetrix Electronics and suitable for microprocessor core supplies, SCSI terminators, battery-powered DSPs, post-regulators, and industrial sensor interfaces requiring stable component supply with long-term manufacturability.

Supply support for LP38513S-1.8/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 high-reliability components for industrial, automotive, and communications markets.

The LP38513S-1.8/NOPB belongs to TI's ultra-low-dropout linear regulator product line, engineered specifically for high-current, low-voltage digital power delivery in space- and efficiency-constrained applications such as portable computing and dense server modules.

FAQ

What is the minimum input voltage required for LP38513S-1.8/NOPB to maintain regulation?

The LP38513S-1.8/NOPB requires a minimum input voltage of 2.25 V to sustain 1.8-V output regulation under full 3-A load. At this condition, the device operates at its specified maximum dropout voltage of 425 mV. Input voltages below 2.25 V will cause the ERROR flag to assert and output voltage to collapse, per the absolute maximum ratings table in the SNVS361E datasheet.

Does LP38513S-1.8/NOPB require external pull-up resistors, and if so, where?

Yes, LP38513S-1.8/NOPB requires an external pull-up resistor on the ERROR pin - valued between 2 kΩ and 20 kΩ - connected to the OUT pin (not VIN). This is mandatory because the ERROR pin is open-drain. The EN pin also requires external biasing (e.g., 10-kΩ pullup to IN) since it has no internal pullup or pulldown, as confirmed in Section 7.4.1 of the LP38513S-1.8/NOPB datasheet.

Can LP38513S-1.8/NOPB operate with Z5U or Y5V ceramic capacitors?

No, LP38513S-1.8/NOPB is not recommended for use with Z5U or Y5V dielectric capacitors. Per Section 8.2.2.1.2 of the datasheet, these types lose >60% capacitance at half-rated voltage and >50% over temperature, violating the 10-µF minimum requirement for stability. X7R or X5R ceramics are strongly recommended to maintain capacitance within ±20% across voltage and temperature.

What thermal considerations apply to LP38513S-1.8/NOPB in DDPAK/TO-263 package?

LP38513S-1.8/NOPB in the KTT (DDPAK/TO-263) package has RθJA = 32.9°C/W and RθJC(bot) = 1.0°C/W. To avoid thermal shutdown at 3 A, the PCB must provide adequate copper area tied to the exposed thermal tab (Pin 3/GND). Junction temperature must stay ≤125°C; using Equation PD = (VIN−1.8)×3 + VIN×0.012, designers should verify thermal design with ΨJB = 17.3°C/W and measured board temperature.

How does the ERROR flag behave when the EN pin is pulled low?

When the EN pin is pulled low, LP38513S-1.8/NOPB disables the regulator and forces the ERROR flag low immediately - regardless of actual VOUT level. This behavior is explicitly documented in Section 7.3.3 and Figure 16 of the datasheet. The ERROR flag resumes monitoring VOUT only after EN rises above 0.85 V and regulation re-establishes.