Texas Instruments TPS78601KTTRG3

Overview

TPS78601KTTRG3 from Texas Instruments is an adjustable 1.5-A low-dropout linear regulator with enable, ultralow noise (48 µV_RMS at 3 V output), high PSRR (49 dB at 10 kHz), and fast start-up (50 µs). It operates from 2.7 V to 5.5 V input and delivers stable output voltage programmable from 1.225 V to 5.5 V – used in RF receiver power rails requiring clean, regulated bias.

For engineers reviewing the TPS78601KTTRG3 datasheet, TPS78601KTTRG3 pinout, TPS78601KTTRG3 application, or TPS78601KTTRG3 equivalent, key selection criteria include dropout voltage (390 mV at 1.5 A), NR-pin noise filtering capability, thermal performance in TO-263-5 package, and compatibility with 1-µF ceramic output capacitors.

Technical Context

The TPS78601KTTRG3 implements a PMOS pass transistor architecture enabling low dropout and reverse-current protection via integrated back diode. Its bandgap reference (1.225 V) feeds a precision error amplifier driving the pass element, with internal current limiting (~2.8 A) and thermal shutdown (~165°C).

It features dedicated NR (noise-reduction) pin connected to the reference through a 250-kΩ internal resistor, allowing external bypass capacitor (0.001–0.1 µF) to form a low-pass filter that reduces reference noise contribution to output. Enable logic thresholds are 1.7 V (high) and 0.7 V (low), supporting direct microcontroller GPIO control.

Key Specifications

Pinout & Package

TPS78601KTTRG3 is housed in a TO-263-5 (KTT) thermally enhanced package with exposed tab electrically connected to GND. The 10.16 mm × 8.42 mm body supports high-power dissipation via PCB copper area and thermal vias.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS78601KTTRG3, TPS79601DRBR offers lower quiescent current but forfeits noise-reduction flexibility, while LP5907MFX-3.3/NOPB provides superior noise performance at much lower current and fixed output-neither matches the combination of adjustability, 1.5-A capability, and NR-controlled noise tailoring of the TPS78601KTTRG3.

Availability

TPS78601KTTRG3 is available at Aetrix Electronics and suitable for RF receiver power supplies, high-resolution audio DAC biasing, portable Bluetooth transceiver cores, and medical sensor signal conditioning requiring stable component supply across production lifecycles.

Supply support for TPS78601KTTRG3 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 company designing analog ICs, embedded processors, and connectivity solutions for industrial, automotive, and consumer markets.

The TPS786 family was engineered specifically for noise-sensitive analog and RF power delivery, emphasizing ultralow output noise, high PSRR, fast transient response, and compatibility with miniature ceramic capacitors in compact packages.

FAQ

What is the maximum output voltage range supported by the TPS78601KTTRG3?

The TPS78601KTTRG3 is an adjustable LDO with output voltage programmable from 1.225 V to 5.5 V using an external resistor divider on the FB pin. Its internal 1.225-V reference and design allow stable regulation up to 5.5 V minus dropout, making it suitable for generating diverse analog and digital supply rails. The TPS78601KTTRG3 achieves this across its full operating temperature range (–40°C to +125°C) with ±2% output accuracy under load.

How does the NR pin on the TPS78601KTTRG3 reduce output noise?

The NR pin on the TPS78601KTTRG3 connects internally to the voltage reference through a 250-kΩ resistor. Adding an external capacitor (0.001–0.1 µF) between NR and GND forms an RC low-pass filter that attenuates reference noise before it modulates the error amplifier. With a 0.1-µF capacitor, the TPS78601KTTRG3 achieves 48 µV_RMS output noise (100 Hz–100 kHz); reducing capacitance increases PSRR bandwidth but raises noise floor. This feature is unique to the TPS78601KTTRG3 among TI's 1.5-A LDOs.

Can the TPS78601KTTRG3 operate with only a 1-µF output capacitor?

Yes, the TPS78601KTTRG3 is explicitly designed to be stable with a minimum 1-µF ceramic output capacitor - a key differentiator from legacy LDOs requiring ≥10 µF tantalum. This specification is validated across all operating conditions (0–1.5 A load, –40°C to +125°C) per the official datasheet. Using larger capacitors (e.g., 2.2 µF or 10 µF) improves transient response and PSRR but is not required for stability. The TPS78601KTTRG3's internal compensation eliminates need for external compensation networks.

What thermal performance can be expected from the TPS78601KTTRG3 in its TO-263-5 package?

In the TO-263-5 (KTT) package, the TPS78601KTTRG3 has a junction-to-ambient thermal resistance (R_θJA) of 40.7°C/W under JEDEC-standard PCB conditions (2s2p board, 5×4 thermal via array to ground plane). With proper PCB layout - including soldering the exposed tab directly to ≥1 in² copper area - it sustains 1.5 A continuous output at ambient temperatures up to +85°C without thermal shutdown. Derating curves in the datasheet confirm operation up to +125°C junction temperature.

Does the TPS78601KTTRG3 include reverse-current protection?

Yes, the TPS78601KTTRG3 integrates reverse-current protection via the inherent body diode of its PMOS pass transistor. When input voltage falls below output voltage (e.g., during system power-down), current flows from OUT to IN through this diode. While unidirectional and not actively limited, this feature prevents external back-feed issues and eliminates need for discrete blocking diodes in most applications. The TPS78601KTTRG3 datasheet confirms this behavior and notes that extended reverse-bias operation may require external current limiting if sustained.