Texas Instruments LM5165YDRCT

Overview

LM5165YDRCT from Texas Instruments is a 3-V to 65-V input, 150-mA synchronous buck converter with ultra-low 10.5-µA no-load quiescent current, fixed 3.3-V output, and integrated 2-Ω PMOS high-side and 1-Ω NMOS low-side switches in a 3-mm × 3-mm VSON-10 package. It delivers regulated bias power for industrial sensors and automotive modules operating across wide input transients.

For engineers reviewing the LM5165YDRCT datasheet, LM5165YDRCT pinout, LM5165YDRCT application, or LM5165YDRCT equivalent, this page provides verified technical context, validated pin functions, confirmed EMI compliance (EN55022/CISPR 22), real-world efficiency curves at 3.3 V/150 mA, and two rigorously cross-checked alternative parts with documented functional differences.

Technical Context

The LM5165YDRCT implements a Constant On-Time (COT) or Pulse Frequency Modulation (PFM) control architecture with no loop compensation required. Its integrated P-channel high-side switch supports true 100% duty cycle operation, enabling ultra-low dropout down to VIN – VOUT ≈ 0.3 V at full load.

It features programmable current limit (four discrete levels via ILIM resistor), active slew-rate control for EMI reduction, monotonic start-up into prebiased outputs, and precision enable with adjustable UVLO hysteresis via the HYS pin - all within a thermally enhanced VSON-10 package with exposed thermal pad.

Key Specifications

Pinout & Package

LM5165YDRCT uses a 10-pin, 3-mm × 3-mm VSON package (DRC) with 0.5-mm pitch and exposed thermal pad connected to GND for optimal thermal performance (R_θJB = 22.1°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM5165XDRCT, LM5165YDRCT provides tighter 3.3-V regulation (±2.1% vs ±2.2%) and lower dropout at light loads; compared with TPS54202DRCT, it offers 77% lower quiescent current and zero-compensation simplicity but sacrifices output current headroom and external FET scalability.

Availability

LM5165YDRCT is available at Aetrix Electronics and suitable for industrial sensor nodes, automotive body electronics, and PLC I/O modules requiring stable component supply with guaranteed long-term manufacturability and consistent parametric performance.

Supply support for LM5165YDRCT 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 over 50 years of power management innovation and broad distribution through authorized channels.

The LM5165 family was designed specifically for ultra-low-IQ, wide-input-voltage DC-DC conversion in space- and power-constrained industrial and automotive applications - prioritizing simplicity, reliability, and EMI robustness over feature bloat.

FAQ

What is the maximum output current capability of the LM5165YDRCT?

The LM5165YDRCT delivers up to 150 mA of continuous DC output current in Constant On-Time (COT) mode at 3.3 V. In Pulse Frequency Modulation (PFM) mode, the maximum rated output current is 100 mA. These limits are defined by thermal constraints and internal current-limit settings, with peak current thresholds configurable via the ILIM pin resistor. The LM5165YDRCT maintains regulation across its full 3-V to 65-V input range at these load levels when used with appropriate external components and PCB thermal design.

Does the LM5165YDRCT require external compensation components?

No, the LM5165YDRCT does not require external loop compensation components. Its Constant On-Time (COT) and Pulse Frequency Modulation (PFM) control architectures are inherently stable across wide input voltage and load ranges, eliminating the need for external RC networks typically required in voltage-mode or current-mode controllers. This simplifies design, reduces BOM count, and accelerates time-to-market - a key differentiator confirmed in Section 7.1 of the official LM5165 datasheet (SNVSA47D).

How does the LM5165YDRCT achieve ultra-low quiescent current?

The LM5165YDRCT achieves 10.5-µA no-load quiescent current through architectural optimizations including deep-sleep circuitry that powers down non-essential blocks during light-load PFM operation, a highly efficient internal LDO bias rail, and minimized gate-drive losses in its integrated PMOS/NMOS power stage. This value is measured at TJ = 25°C with VFB = 1.5 V and is validated per Section 6.5 of the LM5165 datasheet. At 65-V input, IQ increases only marginally to 11 µA, confirming robustness across the full input range.

Can the LM5165YDRCT operate with 100% duty cycle, and why is that important?

Yes, the LM5165YDRCT supports true 100% duty cycle operation due to its integrated P-channel high-side MOSFET, which eliminates the need for a bootstrap capacitor and enables regulation even when VIN approaches VOUT. This is critical in automotive cold-crank scenarios where input voltage can dip to 3.2 V while maintaining a stable 3.3-V output - a capability explicitly documented in Section 7.3.1 and Figure 6-29 of the LM5165 datasheet. Dropout voltage remains below 300 mV at full 150-mA load.

Is the LM5165YDRCT pin-compatible with other devices in the LM5165 family?

Yes, the LM5165YDRCT is pin-to-pin compatible with the LM5165XDRCT (5-V fixed) and the adjustable-output LM5165DRCT, sharing identical VSON-10 (DRC) packaging, pinout, and footprint. This allows hardware reuse across 3.3-V, 5-V, and programmable-output designs. However, internal feedback dividers differ between fixed-output variants, so swapping LM5165YDRCT for LM5165XDRCT requires verifying downstream logic voltage tolerances and updating no-connect handling on the VOUT/FB pin.