Texas Instruments TLV75518PDYDR

Overview

TLV75518PDYDR from Texas Instruments is a 500mA, low-quiescent-current (25μA typ), fixed 1.8V output LDO regulator in thermally enhanced SOT-23-5 (DYD) package with exposed thermal pad. It operates from 1.45V to 5.5V input, delivers ≤1% output accuracy at 85°C, and maintains regulation with only 1µF ceramic output capacitor - ideal for space-constrained, battery-powered MCU core supplies.

For engineers reviewing the TLV75518PDYDR datasheet, TLV75518PDYDR pinout, TLV75518PDYDR application, or TLV75518PDYDR equivalent, key selection criteria include its 238mV max dropout at 500mA (for 3.3VOUT), active output discharge, foldback current limit, and 60.3°C/W R_θJA on EVM - all critical for portable power integrity and thermal management in compact designs.

Technical Context

The TLV75518PDYDR uses a PMOS pass transistor architecture enabling ultra-low dropout and high PSRR (46dB @ 100kHz). Its internal soft-start ensures monotonic V_OUT rise and limits inrush current during power-up, while undervoltage lockout (UVLO) with 1.21–1.44V threshold prevents erratic behavior during brownout conditions.

Functional modes include normal regulation, dropout (where V_OUT tracks V_IN), and disabled state with active pulldown (120Ω internal resistor to GND). Thermal shutdown triggers at 165°C and resets at 155°C, providing cyclic protection against sustained overload without requiring external circuitry.

Key Specifications

Pinout & Package

SOT-23-5 package with exposed thermal pad (DYD variant), 2.9mm × 2.8mm footprint. Thermal pad must be soldered to large-area ground plane for optimal thermal performance (R_θJA = 60.3°C/W on EVM).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC75518DBVR and TPS7A2018PDQNR, TLV75518PDYDR uniquely balances 500mA drive, 25μA IQ, active discharge, and thermally enhanced packaging - making it optimal for portable systems requiring robust power sequencing and thermal headroom in minimal area.

Availability

TLV75518PDYDR is available at Aetrix Electronics and suitable for portable MCU power, camera module supply, white goods control panels, and grid infrastructure relays requiring stable component supply with traceable sourcing and lifecycle continuity.

Supply support for TLV75518PDYDR 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 specializing in analog and embedded processing technologies, with leadership in power management ICs for industrial, automotive, and consumer markets.

The TLV755P product line delivers ultra-small, low-I_Q, low-dropout regulators optimized for battery-powered and space-constrained applications - targeting modern MCU core, I/O, and sensor bias requirements across portable, appliance, and infrastructure equipment.

FAQ

What is the maximum dropout voltage specification for TLV75518PDYDR at full 500mA load?

The TLV75518PDYDR has a maximum dropout voltage of 420mV at 500mA and +85°C ambient temperature. This value is specified for 1.8V output in the DYD package and ensures reliable regulation from input voltages as low as 2.22V under worst-case thermal conditions - critical for maintaining operation during battery discharge in portable systems.

Does TLV75518PDYDR require an external pull-up resistor on the EN pin?

No, TLV75518PDYDR does not require an external pull-up resistor on the EN pin. It features an internal weak pull-down (not pull-up), and the EN pin is active-high with V_HI ≥1V and V_LO ≤0.3V thresholds. For always-on operation, connect EN directly to IN; for controlled enable/disable, drive EN with a logic signal referenced to the same ground as TLV75518PDYDR.

Can TLV75518PDYDR operate stably with less than 1µF output capacitance?

No, TLV75518PDYDR requires a minimum of 1µF ceramic output capacitance for guaranteed stability across all operating conditions. The datasheet specifies that effective capacitance at the OUT pin must exceed 0.47µF after derating, and 1µF is the nominal design value ensuring phase margin and transient response meet specifications - using smaller values risks oscillation or poor load regulation.

What is the purpose of the NC pin on TLV75518PDYDR, and how should it be handled in PCB layout?

The NC (no connection) pin on TLV75518PDYDR is not internally bonded and serves no electrical function. In PCB layout, it must remain unconnected - neither routed nor soldered to any net. TI recommends leaving it floating or optionally connecting it to GND via a small thermal relief to aid soldering and mechanical stability, but never to a signal or power net.

How does the active output discharge feature of TLV75518PDYDR improve system reliability?

The active output discharge in TLV75518PDYDR uses a 120Ω internal switch to pull the OUT pin to GND when EN is deasserted. This ensures rapid, deterministic discharge of output capacitance - preventing floating voltages that could cause latch-up in downstream ICs, enabling safe multi-rail power sequencing, and guaranteeing a known low-impedance state before next power-up cycle.