Texas Instruments TLV75509PDQNT

Overview

TLV75509PDQNT from Texas Instruments is a 500mA, low-quiescent-current (25μA typical), fixed 0.9V output low-dropout regulator in a 1mm × 1mm X2SON-4 package. It operates from 1.45V to 5.5V input, delivers ±1.2% output accuracy over –40°C to +85°C, and features active output discharge, foldback current limiting, and stable operation with only 1µF ceramic output capacitance. It powers core rails in space-constrained portable MCUs and sensor nodes.

For engineers reviewing the TLV75509PDQNT datasheet, TLV75509PDQNT pinout, TLV75509PDQNT application, or TLV75509PDQNT equivalent, key selection criteria include dropout voltage at 500mA (max 1080mV for 0.9V output), thermal resistance (R_θJA = 168.4°C/W per JEDEC), enable threshold (V_HI = 1V), soft-start behavior, and compatibility with ultra-small PCB footprints.

Technical Context

The TLV75509PDQNT uses a PMOS pass transistor architecture enabling low dropout and high PSRR (46dB at 100kHz). Its internal bandgap reference and error amplifier deliver tight regulation across temperature and load, while undervoltage lockout (UVLO) with 1.3V nominal threshold and 40mV hysteresis ensures clean startup under marginal input conditions.

Functional modes include normal regulation, dropout (where V_OUT tracks V_IN), and disabled state with active pulldown (120Ω internal resistor). The device integrates thermal shutdown (165°C trip), foldback current limit (720mA typ at 0.9V), and EN-controlled sequencing - all optimized for battery-powered systems requiring predictable power-up and fast output discharge.

Key Specifications

Pinout & Package

TLV75509PDQNT uses the X2SON-4 (DQN) package: 1mm × 1mm, 0.35mm pitch, no exposed thermal pad. Pin 1 (OUT) and Pin 2 (GND) are diagonally opposite; Pin 3 (EN) and Pin 4 (IN) complete the square layout. This ultra-compact footprint minimizes board area in wearable and medical sensor modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLS850F0TESK and MCP1804T-0902E/OT, TLV75509PDQNT uniquely combines 0.9V fixed output, X2SON-4 size, active discharge, and guaranteed 1080mV dropout at 500mA - making it optimal for miniaturized, battery-sensitive consumer and industrial edge devices where footprint and predictable shutdown behavior are non-negotiable.

Availability

TLV75509PDQNT is available at Aetrix Electronics and suitable for portable medical sensors, wearable fitness trackers, industrial wireless sensor nodes, and smart home edge controllers requiring stable component supply and long-term production continuity.

Supply support for TLV75509PDQNT 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 specializing in analog, embedded processing, and power management technologies, serving industrial, automotive, and consumer markets since 1930.

The TLV755P family was designed specifically for space-constrained, battery-powered applications demanding ultra-low IQ, small solution size, and robust protection features - targeting next-generation IoT endpoints and ultra-portable electronics.

FAQ

What is the maximum dropout voltage of TLV75509PDQNT at 500mA output current?

The maximum dropout voltage of TLV75509PDQNT is 1080mV at 500mA output current, specified over –40°C to +85°C ambient temperature. This value applies to the DQN (X2SON-4) package and defines the minimum VIN–VOUT differential required to maintain regulation under worst-case thermal and load conditions. At 25°C, typical dropout is lower - approximately 675mV.

Does TLV75509PDQNT require an external capacitor on the EN pin for stable operation?

No, TLV75509PDQNT does not require an external capacitor on the EN pin. The EN pin has negligible input capacitance (<10pF) and draws only 10nA typical current. However, if EN is driven by a high-impedance source or long trace, a small 100pF ceramic capacitor to GND may reduce noise susceptibility - but this is not a datasheet requirement for basic functionality of TLV75509PDQNT.

Can TLV75509PDQNT be used with a 0.47µF output capacitor?

TLV75509PDQNT is specified to be stable with ≥1µF ceramic output capacitance. While 0.47µF may work in some low-current, low-transient scenarios, it violates the minimum recommended value and risks instability, overshoot, or oscillation - especially during load steps or input transients. For reliable operation across temperature and production variance, always use ≥1µF X5R/X7R ceramic capacitor on TLV75509PDQNT's OUT pin.

What is the purpose of the active pulldown resistor in TLV75509PDQNT?

The active pulldown resistor (120Ω) in TLV75509PDQNT connects OUT to GND when the device is disabled (EN < 0.3V), ensuring rapid and deterministic discharge of output capacitance. This prevents floating voltage states that could cause undefined logic levels or unintended wake-up in downstream circuits - a critical feature for reliable reset sequencing in TLV75509PDQNT-based systems.

Is TLV75509PDQNT compatible with ceramic capacitors having 20% DC bias derating?

Yes, TLV75509PDQNT is fully compatible with X5R/X7R ceramic capacitors exhibiting up to 50% DC bias derating - as confirmed in TI's datasheet Section 7.1.1. For a 1µF nominal capacitor rated at 6.3V, effective capacitance at 0.9V bias remains well above the 0.47µF stability threshold. Always verify effective C_OUT using manufacturer DC bias curves before finalizing TLV75509PDQNT designs.