Texas Instruments TPS74701QDRCRM3Q1

Overview

TPS74701QDRCRM3Q1 from Texas Instruments is an AEC-Q100 Grade 1 automotive LDO linear regulator delivering 500 mA output current with programmable soft-start, 0.95% output accuracy over line/load/temperature, and ultra-low 20 mV typical dropout at 500 mA (V_BIAS = 5 V). It supports adjustable V_OUT from 0.8 V to 3.6 V and operates with input as low as 0.8 V using dedicated V_BIAS (2.7–5.5 V), enabling robust power sequencing in infotainment domain controllers.

For engineers reviewing the TPS74701QDRCRM3Q1 datasheet, TPS74701QDRCRM3Q1 pinout, TPS74701QDRCRM3Q1 application, or TPS74701QDRCRM3Q1 equivalent, key selection considerations include its dual-rail input architecture (VIN + VBIAS), monotonic soft-start control via external capacitor, open-drain power-good signaling for supply monitoring, and guaranteed stability with ≥2.2 µF ceramic output capacitance - all in a space-constrained 3-mm × 3-mm 10-pin VSON package.

Technical Context

The TPS74701QDRCRM3Q1 employs an NMOS pass transistor architecture powered by a separate V_BIAS rail, decoupling internal control circuitry from VIN and enabling stable regulation down to 0.8 V output with minimal input headroom. This topology eliminates output capacitor dependency on loop stability - unlike PMOS LDOs - and delivers superior transient response, especially under low-VIN conditions.

Its programmable soft-start uses a voltage-controlled ramp generated by charging an external capacitor on the SS pin, ensuring monotonic startup and limiting inrush current into large downstream capacitive loads. The integrated power-good (PG) output provides active-high open-drain status indication with 85–94% V_OUT trip threshold and 3% hysteresis, supporting precise supply sequencing in multi-rail automotive systems.

Key Specifications

Pinout & Package

TPS74701QDRCRM3Q1 is housed in a thermally enhanced 3-mm × 3-mm, 10-pin VSON (DRC) package with exposed thermal pad connected to GND for optimal junction-to-board thermal resistance (R_θJB = 19.5 °C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS74701QDRCRM3Q1, TPS74801QDRCRQ1 offers identical packaging and qualification but sacrifices adjustability and power-good signaling, while NCP1117ST50T3G provides higher current in a through-hole package but omits all automotive-grade features and advanced control functions.

Availability

TPS74701QDRCRM3Q1 is available at Aetrix Electronics and suitable for automotive head units, infotainment systems, and telematics control units requiring stable component supply with full AEC-Q100 traceability and long-term production support.

Supply support for TPS74701QDRCRM3Q1 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 automotive electronics, with decades of experience in high-reliability power management solutions.

The TPS747xx-Q1 product line delivers automotive-grade LDOs optimized for infotainment, ADAS, and body electronics - emphasizing low noise, precise accuracy, programmable sequencing, and thermal resilience in harsh environments.

FAQ

What is the minimum input voltage required for TPS74701QDRCRM3Q1 to regulate a 1.2-V output?

The TPS74701QDRCRM3Q1 requires VIN ≥ V_OUT + V_DO, where V_DO depends on operating conditions. With V_BIAS ≥ V_OUT + 1.62 V, typical dropout is 20 mV at 500 mA - so VIN ≥ 1.22 V suffices. Without V_BIAS assist (i.e., VIN = V_BIAS), minimum VIN is ~2.5 V due to higher V_BIAS dropout. Always verify against recommended operating conditions in the datasheet for your specific V_OUT and load.

How does the V_BIAS pin improve transient response in TPS74701QDRCRM3Q1 compared to single-rail LDOs?

The V_BIAS pin powers the TPS74701QDRCRM3Q1's error amplifier, reference, and gate driver independently of VIN. This decouples control-loop bandwidth from input rail stability, enabling faster response to load steps even when VIN sags - critical in automotive cold-crank or battery-dip scenarios. Single-rail LDOs suffer degraded transient performance under low-VIN conditions because their internal circuitry loses headroom; TPS74701QDRCRM3Q1 avoids this limitation entirely.

Can TPS74701QDRCRM3Q1 be used without connecting the V_BIAS pin?

No - the V_BIAS pin must be connected to a valid supply between 2.7 V and 5.5 V for proper operation. Leaving it unconnected disables internal circuitry, preventing regulation. If no auxiliary rail exists, tie V_BIAS to VIN (with ≥0.1 µF local bypass), but note that dropout then increases to ~1.3 V and efficiency drops significantly at high I_OUT. The TPS74701QDRCRM3Q1 is designed for dual-rail use; omitting V_BIAS compromises its core low-dropout advantage.

What is the purpose of the SS (soft-start) pin on TPS74701QDRCRM3Q1, and how is it configured?

The SS pin on TPS74701QDRCRM3Q1 controls the output voltage ramp rate during startup via an external capacitor to GND. Charging current (~530 nA) flows into this capacitor, generating a linear voltage ramp that modulates the pass transistor gate - ensuring monotonic V_OUT rise and limiting inrush current. A 1-nF capacitor yields ~250 µs startup; larger values extend ramp time proportionally. Leaving SS unconnected defaults to internal ~250 µs ramp, but external control is required for precise sequencing in multi-supply systems.

Does TPS74701QDRCRM3Q1 require special PCB layout practices for thermal management?

Yes - the TPS74701QDRCRM3Q1's exposed thermal pad must be soldered to a solid GND plane with ≥4 thermal vias (0.3-mm diameter, spaced ≤1 mm apart) to achieve specified R_θJB = 19.5 °C/W. Input/output capacitors should be placed within 2 mm of respective pins, and feedback traces must be routed away from noisy nodes (e.g., switching regulators) to preserve 0.95% accuracy. Avoid splitting the GND plane under the device - uninterrupted copper maximizes heat dissipation and minimizes noise coupling.