Texas Instruments LM53625NQRNLRQ1

Overview

LM53625NQRNLRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive synchronous buck DC-DC converter delivering 3.3 V at up to 2.5 A, operating from 3.55 V to 36 V input with 2.1-MHz fixed switching frequency and ±1% output voltage accuracy over –40°C to +125°C junction temperature. It integrates high-side/low-side MOSFETs, internal compensation, soft-start, and a dedicated open-drain RESET output with 3-ms release timer - deployed in telematics and instrument cluster power rails.

For engineers reviewing the LM53625NQRNLRQ1 datasheet, LM53625NQRNLRQ1 pinout, LM53625NQRNLRQ1 application, or LM53625NQRNLRQ1 equivalent, key selection considerations include its 3.3-V fixed output with spread-spectrum EMI reduction, wettable-flank VQFN-22 package (5.0 mm × 4.0 mm), 15-µA no-load quiescent current, 0.6-V dropout at 3.5 A/105°C, and AEC-Q100 qualification for automotive under-hood environments.

Technical Context

The LM53625NQRNLRQ1 employs peak-current-mode control with adaptive frequency spreading to maintain regulation down to 300-mV input-output differential while preserving 2.1-MHz operation above dropout. Its flip-chip HotRod QFN architecture minimizes switch-node ringing and parasitic inductance, enabling low-EMI layout in space-constrained automotive modules.

It features dual ground domains (AGND and PGND), integrated 3.1-V LDO (VCC), bootstrap gate drive (CBOOT), external synchronization (SYNC) support between 1.9–2.3 MHz, and pin-selectable forced PWM mode (FPWM) to eliminate light-load frequency modulation - all validated across –40°C to +150°C junction temperature.

Key Specifications

Pinout & Package

VQFN-HR (RNL) 22-pin package, 5.0 mm × 4.0 mm body, 0.5-mm pitch, wettable flanks - optimized for automated optical solder-joint inspection and thermal performance (R_θJB = 5.4°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM53635NQRNLRQ1, the LM53625NQRNLRQ1 offers lower cost and thermal footprint for 2.5-A loads; versus TPS543320RTWR, it provides superior surge immunity and EMI performance at the expense of slightly larger package size - critical for under-hood deployment.

Availability

LM53625NQRNLRQ1 is available at Aetrix Electronics and suitable for telematics control units, automotive head units, and digital instrument clusters requiring stable component supply, AEC-Q100 compliance, and long-term automotive lifecycle support.

Supply support for LM53625NQRNLRQ1 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 deep expertise in automotive-grade power management ICs.

The LM536xx-Q1 product line delivers high-efficiency, low-EMI DC-DC converters engineered specifically for automotive infotainment, ADAS, and body electronics - emphasizing AEC-Q100 reliability, wide input range, and system-level integration.

FAQ

What is the maximum input voltage rating for LM53625NQRNLRQ1, and how does it handle transients?

The LM53625NQRNLRQ1 has an absolute maximum input voltage rating of 40 V across AVIN, PVIN1, and PVIN2 pins. It sustains 42-V transients for ≤500 ms at ≤0.01% duty cycle - enabling direct connection to 12-V/24-V automotive batteries without external TVS or clamping circuits. This transient tolerance is verified per AEC-Q100 stress test conditions and documented in Section 7.1 of the datasheet.

Does LM53625NQRNLRQ1 require external compensation components?

No, LM53625NQRNLRQ1 features fully integrated compensation circuitry. Its peak-current-mode control architecture with built-in error amplifier and PWM comparator eliminates the need for external compensation networks - reducing BOM count, layout complexity, and tuning effort. All stability criteria are met using only the recommended input/output capacitors and inductor specified in the datasheet's typical application circuit.

How does the RESET output of LM53625NQRNLRQ1 behave during startup and fault conditions?

The LM53625NQRNLRQ1 RESET output is an open-drain signal that remains low until the output reaches 96–110% of nominal 3.3 V and remains stable for ≥3 ms. It asserts low again if EN is de-asserted, output drops below 92–96.5% of setpoint, or thermal shutdown occurs. The internal 3-ms release timer and 12–45 µs glitch filter ensure clean, bounce-free reset assertion compatible with microcontroller reset inputs.

Can LM53625NQRNLRQ1 operate with input voltage below 3.55 V?

LM53625NQRNLRQ1 supports minimum input voltage of 3.55 V for full functionality at 1.5 A load (Section 7.6), and 3.9 V at maximum 2.5-A load. Below 3.55 V, regulation is not guaranteed - though the device may sustain operation in dropout with reduced duty cycle and degraded accuracy. Startup requires ≥3.2 V (rising) per UVLO specification, but sustained regulation demands sufficient headroom for the internal high-side FET's R_DS(on) and control loop margin.

What package variant is used by LM53625NQRNLRQ1, and why are wettable flanks important?

LM53625NQRNLRQ1 uses the VQFN-HR (RNL) 22-pin package with 5.0 mm × 4.0 mm body and wettable flanks. Wettable flanks enable automated optical inspection (AOI) of solder joints without X-ray - a critical requirement for automotive manufacturing traceability and zero-defect quality standards. The flip-chip HotRod construction also reduces parasitic inductance by >60% versus conventional QFN, improving EMI and transient response.