Texas Instruments TPS73734DCQ

Overview

TPS73734DCQ from Texas Instruments is a 1A, low-dropout linear regulator with NMOS pass transistor topology, reverse current protection, and 3.4V fixed output voltage in SOT-223-6 package. It operates from 2.2V to 5.5V input, delivers 122mV typical dropout at 1A (new silicon), maintains ±1.5% overall accuracy over line/load/temperature, and stabilizes with ≥1μF ceramic output capacitor. It serves as post-regulator for switching supplies and point-of-load supply for FPGAs and microprocessors.

For engineers reviewing the TPS73734DCQ datasheet, TPS73734DCQ pinout, TPS73734DCQ application, or TPS73734DCQ equivalent, this page provides verified electrical specifications, thermal metrics for DCQ package, functional pin definitions, real-world load transient performance data, and validated alternative options for fixed-output LDO selection in portable and industrial power systems.

Technical Context

The TPS73734DCQ uses an NMOS pass transistor in voltage-follower configuration, enabling ultra-low dropout and inherent reverse current blocking without external diodes. Its BiCMOS process delivers high precision (1.204V internal reference) and low ground current (880µA at 1A, new silicon).

It integrates thermal shutdown (160°C trip), foldback current limiting (1.05–2.2A), and active-high enable with <20nA shutdown current. The DCQ package features exposed thermal pad connected to GND, supporting 76°C/W junction-to-ambient thermal resistance under JEDEC high-K board conditions.

Key Specifications

Pinout & Package

SOT-223-6 (DCQ) package with exposed thermal pad tied to GND; 6.5mm × 7.06mm footprint; recommended 3×2 thermal via array to inner ground plane for thermal management.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output LDO applications.

Compared with TPS73734DCQ, TPS73733DCQ offers identical performance at 3.3V for standard logic rails, while TPS7A3701DCQ trades higher cost for ±1% accuracy - making it suitable for metrology-grade power rails where 0.5% tighter tolerance justifies the premium.

Availability

TPS73734DCQ is available at Aetrix Electronics and suitable for point-of-load regulation, post-regulation for switching supplies, and portable equipment requiring stable component supply with long-term manufacturability and TI's full product lifecycle support.

Supply support for TPS73734DCQ 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, with decades of LDO design expertise and broad industrial qualification.

The TPS737 family is designed for portable, battery-powered, and space-constrained applications requiring ultra-low dropout, reverse current protection, and ceramic-capacitor stability - targeting FPGA, DSP, and microprocessor power rails.

FAQ

What is the minimum input voltage required for TPS73734DCQ to regulate at full 1A load?

The minimum input voltage is determined by dropout: VIN(min) = VOUT + VDO = 3.4V + 0.122V = 3.522V (typical, new silicon). At 1A load and –40°C to +125°C, worst-case dropout is 250mV, so VIN must be ≥3.65V to guarantee regulation across temperature. Below 2.2V input, the device is not functional.

Does TPS73734DCQ require an external capacitor on the NR pin, and what effect does it have?

Yes - TPS73734DCQ is a fixed-output version with NR pin. Connecting a 10nF capacitor from NR to GND reduces output noise by ~3.2× (e.g., from 27µVRMS to ~8.5µVRMS at 3.4V). Without CNR, noise remains at baseline; omitting CNR does not affect stability but increases RMS noise in sensitive analog/RF rails.

Can TPS73734DCQ be used with input voltages below 2.2V, such as 1.8V?

No - TPS73734DCQ has a specified minimum input voltage of 2.2V per Absolute Maximum Ratings and Recommended Operating Conditions. Operation below 2.2V is undefined, may cause output collapse or erratic behavior, and violates datasheet limits. For sub-2.2V inputs, consider TI's TPS7A05 or similar ultra-low-VIN LDOs.

How does the thermal performance of TPS73734DCQ in DCQ package compare between legacy and new silicon?

Thermal resistance (RθJA) for DCQ package is 76°C/W for both legacy and new silicon under JEDEC high-K board conditions. However, new silicon reduces ground current at 1A from 1300µA to 880µA, lowering total power dissipation and resulting junction temperature by ~3.2°C at 1A - improving thermal margin without changing PCB layout.

Is TPS73734DCQ pin-compatible with other TPS737 variants in SOT-223-6 (DCQ) package?

Yes - all TPS737xxyy DCQ variants (e.g., TPS73733DCQ, TPS73725DCQ) share identical pinout, package dimensions, thermal pad connection, and footprint. Only the output voltage differs; EN, NR/FB, IN, OUT, and GND assignments are consistent across the family, enabling drop-in replacement for voltage tuning.