Texas Instruments LM5165QDRCRQ1

Overview

LM5165QDRCRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive synchronous buck converter delivering up to 150 mA at adjustable or fixed 3.3 V/5 V output, operating from 3 V to 65 V input with 10.5 µA no-load quiescent current and integrated 2-Ω PMOS high-side and 1-Ω NMOS low-side switches. It supports PFM/COT control modes, 100% duty cycle operation, and meets CISPR 22 EMI standards for under-hood power supplies.

For engineers reviewing the LM5165QDRCRQ1 datasheet, LM5165QDRCRQ1 pinout, LM5165QDRCRQ1 application, or LM5165QDRCRQ1 equivalent, key selection considerations include ultra-low IQ for always-on systems, wide VIN range for battery transients, programmable current limit for inductor optimization, and dual-mode control for light-load efficiency vs. transient response trade-offs.

Technical Context

The LM5165QDRCRQ1 implements a constant-on-time (COT) or pulse-frequency modulation (PFM) control architecture with input-voltage feedforward to maintain stable switching frequency across 3–65 V input. Its integrated high-side PMOS eliminates bootstrap capacitor requirements and enables true 100% duty cycle for ultra-low dropout operation.

It features a precision 1.223 V ±1% internal reference, monotonic start-up into prebiased outputs, active slew-rate control for EMI reduction, and selectable soft-start (900 µs internal or externally programmable). Thermal shutdown with 10°C hysteresis and AEC-Q100 Grade 1 qualification (–40°C to 125°C ambient) confirm its suitability for automotive power rail conditioning.

Key Specifications

Pinout & Package

LM5165QDRCRQ1 is packaged in a 10-pin VSON (DRC) with 3.00 mm × 3.00 mm body size and 0.5-mm pitch, featuring an exposed thermal pad for enhanced PCB heat dissipation. The package is RoHS-compliant and qualified per AEC-Q100 Grade 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM5165QDRCRQ1, LM5164QDRCRQ1 extends input range and output current with minimal footprint impact, while TPS54160AQRTARQ1 trades ultra-low IQ for high-current flexibility-making LM5165QDRCRQ1 optimal for compact, low-power automotive bias rails where standby current and EMI are primary constraints.

Availability

LM5165QDRCRQ1 is available at Aetrix Electronics and suitable for automotive body electronics, ADAS camera subsystems, and telematics power management requiring stable component supply, AEC-Q100 compliance, and long-term lifecycle support.

Supply support for LM5165QDRCRQ1 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 decades of automotive-grade power management innovation and rigorous AEC-Q100 qualification processes.

The LM5165-Q1 product line delivers ultra-low-IQ, wide-input synchronous buck converters specifically engineered for automotive always-on, infotainment, and ADAS power rails where efficiency, reliability, and EMI performance are critical.

FAQ

What is the maximum junction temperature rating for LM5165QDRCRQ1?

The LM5165QDRCRQ1 has a maximum junction temperature of 150°C and thermal shutdown activation at 170°C with 10°C hysteresis. This allows continuous operation in under-hood environments up to 125°C ambient when properly heatsinked via the exposed thermal pad. Derating curves in the datasheet confirm safe operation at full 150-mA load up to 105°C ambient in the DRC package.

Does LM5165QDRCRQ1 support fixed 3.3-V output without external feedback resistors?

Yes, LM5165QDRCRQ1 is the adjustable-output variant, but the LM5165Y-Q1 (3.3-V fixed) and LM5165X-Q1 (5-V fixed) are pin-compatible alternatives. LM5165QDRCRQ1 itself uses the FB pin with external resistor divider for adjustable output; it does not have internal fixed-divider connections. For fixed 3.3 V, select LM5165YDRCRQ1 instead.

How is the current limit programmed on LM5165QDRCRQ1?

The current limit on LM5165QDRCRQ1 is set via the ILIM pin using a single resistor to GND, selecting one of four factory-trimmed thresholds: 48–75 mA, 100–146 mA, 155–207 mA, or 215–270 mA (depending on package). Shorting ILIM to GND selects the highest level. The exact value is temperature- and VIN-dependent, with typical variation shown in Figure 6-14 and Figure 6-15 of the datasheet.

Can LM5165QDRCRQ1 operate with 100% duty cycle, and what is the minimum dropout voltage?

Yes, LM5165QDRCRQ1 supports true 100% duty cycle due to its high-side PMOS switch, enabling operation when VIN approaches VOUT. Minimum dropout is determined by IOUT × RDSON1 (2 Ω typ), so at 150 mA, dropout is ~300 mV - significantly lower than NMOS-based buck controllers requiring bootstrap voltage. This ensures regulation during cold-crank down to ~3.6 V for a 3.3-V output.

What package options are available for LM5165QDRCRQ1, and is the thermal pad required?

LM5165QDRCRQ1 is offered exclusively in the 10-pin VSON (DRC) package with 3.0 mm × 3.0 mm body and 0.5-mm pitch. The exposed thermal pad is mandatory for thermal performance - it must be soldered to a large GND copper area on the PCB. Omitting pad connection degrades RθJA from 47.7°C/W to >100°C/W, risking thermal shutdown under load.