Texas Instruments TPS73701DCQRG4

Overview

TPS73701DCQRG4 from Texas Instruments is a 1A, adjustable-output low-dropout (LDO) voltage 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, delivers ±1.5% overall accuracy over line/load/temperature, and stabilizes with only 1 μF ceramic output capacitor. It serves as a post-regulator for switching supplies in portable, battery-powered systems requiring tight voltage control and low quiescent current.

For engineers reviewing the TPS73701DCQRG4 datasheet, TPS73701DCQRG4 pinout, TPS73701DCQRG4 application, or TPS73701DCQRG4 equivalent, key selection criteria include its 122 mV dropout at 1 A, <20 nA shutdown current, NMOS-based reverse leakage suppression, thermal/foldback current protection, and compatibility with minimal 1 μF ceramic output capacitance - all critical for space-constrained, low-power embedded designs.

Technical Context

The TPS73701DCQRG4 employs 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 (±1.5% total accuracy) while maintaining low ground pin current (880 µA at 1 A, new silicon) and sub-20 nA shutdown IQ.

It features an internal charge pump (~4 MHz) to drive the NMOS gate above VOUT, eliminating dependency on high-VGS MOSFETs. The adjustable version uses FB pin feedback with R1/R2 divider (1.204 V reference), and supports noise reduction via CFB (≤0.1 µF) from FB to OUT - distinct from fixed versions that use NR pin.

Key Specifications

Pinout & Package

TPS73701DCQRG4 is packaged in SOT-223-6 (DCQ), with exposed thermal pad connected to GND. This package supports moderate power dissipation in compact layouts and is widely supported by automated assembly processes.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS73701DCQRG4, TPS73701DRBR offers identical electrical performance in a smaller package but demands more careful thermal design, while TPS7A3701DRBR trades reverse current blocking and ultra-low dropout for tighter accuracy and lower noise - making it suitable only for non-battery-reverse scenarios requiring highest DC precision.

Availability

TPS73701DCQRG4 is available at Aetrix Electronics and suitable for portable instrumentation, battery-powered IoT nodes, and point-of-load microprocessor regulation requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for TPS73701DCQRG4 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 and embedded processing technologies, with decades of expertise in power management ICs for industrial, automotive, and portable applications.

The TPS737 family was designed specifically for high-efficiency, low-noise, reverse-current-protected LDO regulation in battery-sensitive and space-constrained systems - emphasizing ultra-low dropout, minimal external components, and robust fault protection.

FAQ

What is the minimum input voltage required for TPS73701DCQRG4 to regulate a 1.2 V output?

The minimum input voltage for TPS73701DCQRG4 is determined by dropout voltage plus output voltage. With 122 mV typical dropout at 1 A (new silicon), VIN(min) = 1.2 V + 0.122 V = 1.322 V. However, the absolute minimum specified VIN is 2.2 V per datasheet - so TPS73701DCQRG4 requires ≥2.2 V input regardless of output setting, ensuring proper internal bias and charge pump operation.

Does TPS73701DCQRG4 require an external capacitor on the FB pin, and what value is recommended?

Yes, TPS73701DCQRG4 supports a feedback capacitor (CFB) from FB to OUT to reduce output noise and improve load transient response. The datasheet specifies CFB ≤ 0.1 µF; 10 nF is commonly used and verified to reduce RMS noise by ~3× in the 10 Hz–100 kHz band. Larger values degrade stability and are not recommended for TPS73701DCQRG4.

How does the reverse current protection in TPS73701DCQRG4 function, and what is its leakage specification?

TPS73701DCQRG4 achieves reverse current protection via its NMOS pass transistor topology, which inherently blocks current flow from OUT to IN when EN is active but VIN < VOUT. Measured reverse leakage (IREV) is ≤0.1 µA under VEN ≤ 0.5 V and 0 V ≤ VIN ≤ VOUT - critical for battery backup circuits and hot-swap applications where backfeed must be eliminated.

Can TPS73701DCQRG4 be used without the enable (EN) pin connected, and what is the default state?

No - the EN pin of TPS73701DCQRG4 must not be left floating. If unused, it must be tied to IN to ensure reliable enablement. The device has no internal pull-up; floating EN causes undefined behavior and potential malfunction. When tied to IN, TPS73701DCQRG4 operates continuously; when pulled ≤0.5 V, it enters <20 nA shutdown mode with full output disable.

What thermal considerations apply to TPS73701DCQRG4 in SOT-223 (DCQ) package at 1 A load?

In the DCQ package, TPS73701DCQRG4 has RθJA = 76°C/W (legacy silicon) or 76°C/W (new silicon per datasheet Table 5.4). At 1 A with 122 mV dropout, power dissipation is ~122 mW. With 25°C ambient, junction temperature rise is ~9.3°C - well within the –40°C to 125°C operating range. Adequate copper pour and thermal vias under the exposed pad are essential to maintain this margin under sustained load.