Texas Instruments TPS78412BQWDRBRQ1

Overview

TPS78412BQWDRBRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive LDO voltage regulator delivering 300 mA output current with 1.2 V fixed output, ultra-low dropout (115 mV max at 300 mA), ±1.7% output accuracy over –40°C to +150°C junction temperature, and 50-dB PSRR up to 100 kHz - designed for powering noise-sensitive analog circuits in automotive infotainment and instrument cluster systems.

For engineers reviewing the TPS78412BQWDRBRQ1 datasheet, TPS78412BQWDRBRQ1 pinout, TPS78412BQWDRBRQ1 application, or TPS78412BQWDRBRQ1 equivalent, key selection criteria include its wettable-flank VSON-8 package, functional safety documentation support, active output discharge, 25 µA typical quiescent current, and compatibility with low-ESR ceramic capacitors down to 0.47 µF.

Technical Context

The TPS78412BQWDRBRQ1 implements a PMOS pass transistor architecture enabling ultra-low dropout and high PSRR across DC to 100 kHz. Its internal 500-µs soft-start limits inrush current during power-up, while foldback current limiting reduces thermal stress under overload conditions.

It features an enable input with defined logic thresholds (VEN(HI) = 0.85 V min), active pulldown circuitry for rapid output discharge when disabled, and UVLO with 130-mV hysteresis to ensure clean startup from weak or noisy supplies - all validated for automotive Grade 1 operation (–40°C to +125°C ambient, –40°C to +150°C junction).

Key Specifications

Pinout & Package

TPS78412BQWDRBRQ1 uses the wettable flank VSON-8 (DRB) package (3.00 mm × 3.00 mm), optimized for automated optical inspection (AOI) and high-reliability automotive solder joints. Thermal pad is internally connected to GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS78412QWDRBRQ1 and TLV76712QWDRBRQ1, the TPS78412BQWDRBRQ1 uniquely combines wettable flank packaging for automotive AOI, full AEC-Q100 Grade 1 qualification, functional safety documentation, and 300-mA output capability - making it the only option qualified for high-integrity, high-current automotive LDO roles.

Availability

TPS78412BQWDRBRQ1 is available at Aetrix Electronics and suitable for automotive head units, hybrid instrument clusters, and telematics control units requiring stable component supply with full AEC-Q100 traceability and long-term production support.

Supply support for TPS78412BQWDRBRQ1 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 and signal chain solutions.

The TPS784-Q1 product line delivers high-PSRR, low-IQ LDOs engineered specifically for automotive infotainment, ADAS, and body electronics - emphasizing functional safety readiness, thermal robustness, and AEC-Q100 compliance.

FAQ

What is the maximum input voltage rating for the TPS78412BQWDRBRQ1?

The TPS78412BQWDRBRQ1 has an absolute maximum input voltage of 6.5 V, with recommended operating input voltage ranging from 1.65 V to 6.0 V. Exceeding 6.5 V risks permanent damage; operation above 6.0 V is outside specified conditions and may degrade long-term reliability. The device's UVLO threshold (1.32 V to 1.6 V) ensures safe startup only when input is sufficiently stable.

Does the TPS78412BQWDRBRQ1 require an external feedback resistor network?

No, the TPS78412BQWDRBRQ1 is a fixed-output 1.2-V LDO and does not require external feedback resistors. Unlike adjustable versions (e.g., TPS78401), it integrates the feedback divider internally. Pin 4 is NC (no-connect), not FB - confirming its fixed-output configuration. This simplifies design, reduces BOM count, and improves accuracy by eliminating resistor tolerance effects.

What is the thermal performance of the TPS78412BQWDRBRQ1 in its VSON-8 package?

The TPS78412BQWDRBRQ1 in the wettable flank VSON-8 (DRB) package has a junction-to-board thermal resistance (RθJB) of 34.3°C/W and junction-to-ambient (RθJA) of 61.8°C/W under standard JEDEC conditions. With proper PCB layout - including a solid thermal pad connected to a ≥1-in² GND plane - it sustains 300 mA continuous output at +125°C ambient without thermal shutdown, leveraging its 150°C max junction rating.

How does the active output discharge function work in the TPS78412BQWDRBRQ1?

The TPS78412BQWDRBRQ1 includes an internal active pulldown circuit that engages when EN is driven low, connecting OUT to GND through a ~120-Ω switch. This discharges the output capacitor rapidly (typically within tens of microseconds), preventing residual voltage from powering downstream ICs or causing undefined logic states. It eliminates need for external bleed resistors, saving board space and power in automotive systems requiring strict power domain isolation.

Is the TPS78412BQWDRBRQ1 pin-compatible with other members of the TPS784-Q1 family?

The TPS78412BQWDRBRQ1 shares the same DRB (VSON-8) footprint and pinout as other fixed-output variants in the TPS784-Q1 family (e.g., TPS78433, TPS78450), with identical IN, GND, EN, NC, and OUT assignments. However, adjustable versions (e.g., TPS78401) use FB instead of NC on Pin 4 - making them electrically incompatible without schematic and layout changes. Always verify pin function tables before substitution.