Texas Instruments TPS78429QDBVRQ1

Overview

TPS78429QDBVRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive LDO voltage regulator delivering 300 mA output with 0.5% typical accuracy, 115 mV max dropout at 3.3 V_OUT, and 50 dB PSRR up to 100 kHz - designed for powering noise-sensitive analog circuits in head units and instrument clusters.

For engineers reviewing the TPS78429QDBVRQ1 datasheet, TPS78429QDBVRQ1 pinout, TPS78429QDBVRQ1 application, or TPS78429QDBVRQ1 equivalent, this page delivers verified electrical specs, thermal performance data, functional safety documentation support, and validated alternative options for automotive power rail design.

Technical Context

The TPS78429QDBVRQ1 implements a precision bandgap reference and error amplifier with foldback current limiting and active output discharge. Its internal 500-µs soft-start reduces inrush current, enabling use with low-input capacitance (≥0.1 µF) while maintaining stability with ≥1 µF ceramic output capacitor.

It operates across –40°C to +125°C ambient (–40°C to +150°C junction), supports input voltages from 1.65 V to 6.0 V, and provides fixed 2.9 V output - compatible with post-regulation of DC/DC converters and low-voltage microcontroller cores requiring high PSRR and tight regulation.

Key Specifications

Pinout & Package

TPS78429QDBVRQ1 uses the 5-pin SOT-23 (DBV) package with wettable flank capability for automated optical inspection. Thermal pad is not present in DBV; GND connection is made via Pin 2 only.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7B8729QKVURQ1 and TLV73329PQDBVRQ1, the TPS78429QDBVRQ1 uniquely balances 300-mA capability, 115-mV dropout, active discharge, and full functional safety documentation - making it optimal for ASIL-B-compliant analog power domains in head units and clusters.

Availability

TPS78429QDBVRQ1 is available at Aetrix Electronics and suitable for automotive head units, hybrid instrument clusters, and telematics control units requiring stable component supply with AEC-Q100 qualification and functional safety support.

Supply support for TPS78429QDBVRQ1 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 specializing in analog and embedded processing technologies, with leadership in automotive-grade power management ICs.

The TPS784-Q1 product line delivers high-accuracy, low-noise LDOs for safety-critical automotive subsystems - engineered specifically for head units, clusters, and telematics where PSRR, thermal robustness, and functional safety documentation are mandatory.

FAQ

What is the output voltage of the TPS78429QDBVRQ1?

The TPS78429QDBVRQ1 is a fixed-output LDO with a nominal output voltage of 2.9 V. This value is factory-trimmed and does not require external feedback components. The output maintains ±1.7% accuracy across the full operating junction temperature range of –40°C to +150°C, ensuring stable operation in demanding automotive environments.

Does the TPS78429QDBVRQ1 support AEC-Q100 qualification?

Yes, the TPS78429QDBVRQ1 is AEC-Q100 qualified for automotive applications, specifically Grade 1 (–40°C to +125°C ambient). It also meets extended junction temperature requirements up to +150°C and includes full qualification test reports, making it suitable for engine bay–adjacent and cabin electronics where reliability is critical.

What is the maximum dropout voltage specification for the TPS78429QDBVRQ1 at full load?

The maximum dropout voltage for the TPS78429QDBVRQ1 is 115 mV at 300 mA output current and 3.3 V_OUT. For its fixed 2.9 V output, the datasheet specifies dropout values based on output voltage bins; at 2.9 V, the max dropout remains ≤115 mV under the same test conditions - enabling efficient operation from 3.3 V intermediate rails.

How does the enable pin (EN) function on the TPS78429QDBVRQ1?

The EN pin on the TPS78429QDBVRQ1 is an active-high logic input with V_EN(HI) ≥ 0.85 V (min) and V_EN(LOW) ≤ 0.425 V (max). Driving EN high enables regulation; pulling it low disables the output and activates the internal 120-Ω pulldown resistor. The pin must never be left floating - if unused, connect directly to IN.

Is functional safety documentation available for the TPS78429QDBVRQ1?

Yes, functional safety documentation is available for the TPS78429QDBVRQ1, including FIT rate data, failure modes and effects analysis (FMEA), and safety analysis reports. These materials support ISO 26262 ASIL-B system-level development and are accessible through Texas Instruments' functional safety portal - confirming the TPS78429QDBVRQ1's role in safety-critical automotive power domains.