Texas Instruments TPS73733DCQG4

Overview

TPS73733DCQG4 from Texas Instruments is a 1A, 3.3V fixed-output low-dropout (LDO) regulator with NMOS pass transistor topology, reverse current protection, and ultra-low dropout voltage of 122 mV typical at 1 A (new silicon). It operates from 2.2 V to 5.5 V input, achieves ±1.5% overall accuracy over line/load/temperature, and stabilizes with only 1 μF ceramic output capacitor. It is used for point-of-load regulation in FPGA and microprocessor power rails where low quiescent current and fast transient response are critical.

For engineers reviewing the TPS73733DCQG4 datasheet, TPS73733DCQG4 pinout, TPS73733DCQG4 application, or TPS73733DCQG4 equivalent, key selection criteria include dropout performance under 1 A load, shutdown current below 20 nA, thermal foldback protection, compatibility with minimal ceramic capacitance, and SOT-223-6 package suitability for thermally constrained PCB layouts.

Technical Context

The TPS73733DCQG4 employs an NMOS pass transistor in voltage-follower configuration, enabling reverse current blocking and relaxed output capacitor ESR requirements. Its BiCMOS process delivers high precision reference (1.204 V nominal) and low ground pin current-880 µA at 1 A load (new silicon).

It integrates a 4-MHz charge pump to drive the NMOS gate above VOUT, ensuring stable regulation even with small VIN–VOUT margins. Thermal shutdown (160°C trip) and foldback current limit protect against sustained overloads and short circuits without external components.

Key Specifications

Pinout & Package

SOT-223-6 package (DCQ), 6.5 mm × 7.06 mm footprint, with exposed thermal pad connected to GND. Pin 1 = IN, Pin 2 = OUT, Pin 3 = GND, Pin 4 = NR/FB (noise reduction/feedback), Pin 5 = EN, Pin 6 = GND (tab). The tab is electrically tied to GND and must be soldered to a thermal pad on PCB for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS73733DCQG4, the TPS73733DRBG4 offers identical regulation performance in a smaller, thermally superior package but demands tighter layout controls, while the TPS79933DBVR trades 80% current capacity for ultra-compact size and lower active IQ-making it unsuitable as a direct replacement in 1 A designs.

Availability

TPS73733DCQG4 is available at Aetrix Electronics and suitable for FPGA power delivery, battery-powered sensor nodes, and industrial I/O module designs requiring stable component supply, long-term manufacturability, and TI-qualified automotive-grade reliability.

Supply support for TPS73733DCQG4 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 ICs, with decades of LDO design expertise and broad automotive/industrial qualification.

The TPS737 family was engineered for portable and high-reliability applications demanding ultra-low dropout, reverse-current blocking, and minimal external components-targeting FPGA, DSP, and microprocessor point-of-load regulation.

FAQ

What is the maximum input voltage rating for the TPS73733DCQG4?

The TPS73733DCQG4 has an absolute maximum input voltage of 6 V, but its recommended operating range is 2.2 V to 5.5 V. Exceeding 5.5 V may cause permanent damage or degrade long-term reliability, even if within absolute ratings. For robust 5 V system integration, ensure transient spikes remain below 5.5 V using appropriate input filtering.

Does the TPS73733DCQG4 require an external capacitor on the NR pin?

Yes-the TPS73733DCQG4's NR pin (Pin 4) accepts an external noise-reduction capacitor (CNR) to lower output voltage noise. With CNR = 10 nF, RMS noise drops from ~27 × VOUT µVRMS to ~8.5 × VOUT µVRMS (10 Hz–100 kHz). Omitting CNR increases noise but does not affect regulation stability, as the device remains stable with only 1 µF on OUT.

Can the TPS73733DCQG4 be used with a 1 µF ceramic output capacitor?

Yes-the TPS73733DCQG4 is explicitly characterized and guaranteed stable with ≥1 µF ceramic output capacitors, including X5R and X7R types. This eliminates reliance on larger, less reliable tantalum or aluminum electrolytic capacitors and simplifies layout in space-constrained designs.

What is the thermal resistance (RθJA) of the TPS73733DCQG4 in its SOT-223 package?

The TPS73733DCQG4 in the DCQ (SOT-223-6) package has a junction-to-ambient thermal resistance (RθJA) of 76°C/W under JEDEC-standard high-K board conditions. Actual thermal performance depends on PCB copper area, thermal vias under the exposed GND tab, and airflow-designers should verify junction temperature using measured or simulated power dissipation.

How does the TPS73733DCQG4 behave during startup and shutdown?

The TPS73733DCQG4 exhibits 431 µs typical startup time (to 3.3 V with 1 µF COUT and 30 Ω load) and enters shutdown with <20 nA ground current when EN is pulled below 0.5 V. During shutdown, the pass transistor gate is fully discharged, ensuring true reverse-current blocking and zero output leakage-critical for battery backup integrity.