Texas Instruments LP38513SX-1.8/NOPB

Overview

LP38513SX-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 max dropout at 3 A, ±2.6% output voltage accuracy over −40°C to +125°C, and fast transient response for microprocessor core supplies. The device uses a PMOS pass transistor, supports ceramic capacitors (≥10 µF), and includes an ERROR flag for output monitoring.

For engineers reviewing the LP38513SX-1.8/NOPB datasheet, LP38513SX-1.8/NOPB pinout, LP38513SX-1.8/NOPB application, or LP38513SX-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 low-ESR ceramic output capacitance.

Technical Context

The LP38513SX-1.8/NOPB implements a PMOS-based LDO architecture with no internal bias on the EN pin, requiring external pull-up or direct connection to VIN. Its ERROR flag is open-drain with 77–94% nominal VOUT threshold and 2.2–5.8% hysteresis, activated only when EN is high.

It delivers stable regulation with 10 µF ceramic input and output capacitors, achieves 73 dB PSRR at 120 Hz, and maintains 0.1% load regulation across 10 mA to 3 A. Thermal shutdown triggers at 165°C with 10°C hysteresis, and short-circuit protection cycles the pass element before thermal limiting engages.

Key Specifications

Pinout & Package

LP38513SX-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 LDO regulator applications.

Compared with TPL7407LADGQR and TPS7A8300RGRT, the LP38513SX-1.8/NOPB uniquely balances 3-A output, 425-mV dropout, ceramic-capacitor compatibility, and integrated ERROR flag - making it optimal for space-constrained, battery-aware microprocessor power where both efficiency and fault visibility matter.

Availability

LP38513SX-1.8/NOPB is available at Aetrix Electronics and suitable for microprocessor core supplies, GTL/SSTL bus terminators, and battery-powered post-regulators requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LP38513SX-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, specializing in analog ICs, embedded processors, and power management solutions for industrial, automotive, and communications markets.

The LP38513SX-1.8/NOPB belongs to TI's ultra-low-dropout linear regulator product line, engineered specifically for high-current, low-voltage digital power domains where fast transient response and ceramic capacitor compatibility are mandatory.

FAQ

What is the minimum input voltage required for LP38513SX-1.8/NOPB to maintain regulation?

The LP38513SX-1.8/NOPB requires a minimum input voltage of 2.25 V to sustain 1.8-V output regulation at full 3-A load. This is determined by its 425-mV maximum dropout voltage specification. Below 2.25 V, the device enters dropout mode and VOUT declines linearly with VIN. Operation below this limit is not guaranteed per datasheet specifications and may result in ERROR flag assertion or thermal overload.

How does the ERROR pin on LP38513SX-1.8/NOPB function, and what external components are needed?

The ERROR pin on LP38513SX-1.8/NOPB is an open-drain output that goes low when VOUT falls below ~85% of nominal (1.53 V). It requires an external pullup resistor of 2–20 kΩ connected to the OUT pin - never to VIN - to avoid parasitic conduction. When EN is low, ERROR is forcibly driven low regardless of VOUT. The pin also exhibits 4% hysteresis, requiring VOUT to rise above ~1.60 V to reassert high.

Can LP38513SX-1.8/NOPB operate with zero-load current, and what is its ground current in that condition?

Yes, LP38513SX-1.8/NOPB operates stably from 0 mA to 3 A load. At zero load, ground pin current (IGND) is typically 10–12 mA - independent of output current due to its PMOS pass architecture. This differs from NPN-based LDOs whose ground current rises with load. The fixed IGND simplifies power budgeting in always-on standby modes.

What ceramic capacitor dielectrics are recommended for LP38513SX-1.8/NOPB, and why are Z5U/Y5V types discouraged?

Texas Instruments recommends X5R or X7R ceramic dielectrics for both input and output capacitors in LP38513SX-1.8/NOPB designs. These maintain ≥80% of rated capacitance across temperature and DC bias. Z5U/Y5V types are discouraged because they can lose >60% capacitance at half-rated voltage and >50% at temperature extremes - risking loop instability and violating the 10-µF minimum requirement specified for stability.

Is LP38513SX-1.8/NOPB compatible with lead-free PCB assembly processes?

Yes, LP38513SX-1.8/NOPB (NOPB suffix) is lead-free and RoHS-compliant, qualified for standard Pb-free reflow profiles per JEDEC J-STD-020. Its DDPAK/TO-263 package supports peak temperatures up to 260°C. The thermal pad must be fully soldered to a thermal plane; voiding >25% of the pad area degrades RθJB and risks exceeding junction temperature limits at 3-A load.