Texas Instruments TLV74328PDQNR

Overview

TLV74328PDQNR from Texas Instruments is a 2.8-V fixed-output, 300-mA low-dropout linear regulator (LDO) in a 4-pin X2SON package (1.0 mm × 1.0 mm), featuring 125 mV dropout at 300 mA, ±1.4% output accuracy over –40°C to +125°C, and 34 µA quiescent current. It delivers stable regulation with only a 1-µF ceramic output capacitor and supports active output discharge via an internal 120-Ω pulldown resistor-ideal for battery-powered portable electronics requiring fast shutdown and low standby power.

For engineers reviewing the TLV74328PDQNR datasheet, TLV74328PDQNR pinout, TLV74328PDQNR application, or TLV74328PDQNR equivalent, key selection criteria include ultra-low quiescent current, guaranteed dropout performance at full load, foldback current limiting for short-circuit robustness, thermal shutdown behavior, and compatibility with minimal 1-µF output capacitance in space-constrained designs.

Technical Context

The TLV74328PDQNR uses a PMOS pass transistor architecture enabling ultra-low dropout and eliminating reverse-current flow through an intrinsic body diode when V_OUT > V_IN. Its undervoltage lockout (UVLO) engages below 1.25 V (falling) and releases above 1.3 V (rising), preventing erratic startup under weak input sources.

Functional modes include normal regulation, dropout operation (where V_OUT = V_IN – V_DO), and disabled state with active pulldown-each governed by independent thresholds for VIN, EN, I_OUT, and junction temperature. Foldback current limiting reduces output current as V_OUT collapses, limiting power dissipation during shorts.

Key Specifications

Pinout & Package

TLV74328PDQNR is housed in a 4-pin X2SON (DQN) package (1.0 mm × 1.0 mm) with an exposed thermal pad electrically connected to GND. The compact footprint supports high-density PCB layouts and improved thermal performance when soldered to a GND plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC76028DBVR and TPS7A0528PDQNR, TLV74328PDQNR uniquely delivers 300 mA output with ≤125 mV dropout and 34 µA IQ in a 1-mm² X2SON package-making it optimal for space- and power-constrained portable systems where full-load efficiency and fast transient response are critical.

Availability

TLV74328PDQNR is available at Aetrix Electronics and suitable for wearable health sensors, IoT edge nodes, portable medical diagnostics, and USB-powered peripheral modules requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for TLV74328PDQNR 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and consumer markets, with decades of LDO design expertise and rigorous qualification standards.

The TLV743P family-including TLV74328PDQNR-is engineered for ultra-low-power, space-constrained portable electronics, emphasizing minimal external components, robust fault protection, and guaranteed performance across extended temperature ranges.

FAQ

What is the minimum input voltage required for TLV74328PDQNR to regulate 2.8 V at 300 mA?

The TLV74328PDQNR requires a minimum input voltage of 2.925 V to maintain regulation at 300 mA, based on its 125-mV dropout specification. Below this, the device enters dropout mode where V_OUT = V_IN – V_DO; operation below 1.25 V input triggers UVLO and disables regulation entirely. This makes TLV74328PDQNR well-suited for single-cell Li-ion (2.8–4.2 V) or regulated 3.0-V supply rails.

Does TLV74328PDQNR require an external pull-up resistor on the EN pin?

Yes, TLV74328PDQNR has no internal pull-up or pull-down on the EN pin. To ensure reliable startup, an external resistor (e.g., 100 kΩ to V_IN) is recommended if EN is not actively driven by a microcontroller GPIO. Without bias, the EN pin floats, risking undefined enable state and potential failure to power up - a critical consideration in battery-powered TLV74328PDQNR designs.

Can TLV74328PDQNR safely drive a 1-µF ceramic output capacitor?

Yes, TLV74328PDQNR is explicitly designed and tested for stability with 1-µF ±20% X5R/X7R ceramic output capacitors - no ESR requirements or additional series resistance needed. This eliminates bulkier, higher-ESR alternatives and reduces solution size. Larger capacitors (e.g., 2.2 µF) are acceptable but provide no stability benefit and may slightly increase startup time.

What happens to the output when TLV74328PDQNR is disabled via the EN pin?

When TLV74328PDQNR is disabled (EN < 0.35 V), its internal 120-Ω pulldown resistor connects OUT to GND, actively discharging the output capacitor. Discharge time depends on C_OUT and parallel load resistance - e.g., with 1 µF and no load, V_OUT falls from 2.8 V to 100 mV in ~3 ms. This prevents floating outputs and supports clean power sequencing in multi-rail systems using TLV74328PDQNR.

How does the foldback current limit protect TLV74328PDQNR during a short circuit?

During a short, TLV74328PDQNR's foldback circuit reduces output current as V_OUT collapses - limiting typical short-circuit current to ~150 mA at 0 V. This cuts power dissipation [(V_IN – V_OUT) × I_SC] versus constant-current limiting, delaying thermal shutdown and allowing brief fault tolerance. If sustained, thermal shutdown at 160°C activates, cycling off/on until the fault clears - protecting both TLV74328PDQNR and the PCB.