Texas Instruments LMR36501P3RPER

Overview

LMR36501P3RPER from Texas Instruments is a 3-V to 65-V, 100-mA synchronous buck DC/DC converter in a 2-mm × 2-mm HotRod™ VQFN-HR (RPE) package, featuring fixed 3.3-V output, PFM light-load operation, adjustable switching frequency (200 kHz–2.2 MHz via RT pin), and –40°C to +150°C junction temperature rating. It delivers >80% peak efficiency at 1 MHz and supports input transients up to 70 V for rugged industrial power rails.

For engineers reviewing the LMR36501P3RPER datasheet, LMR36501P3RPER pinout, LMR36501P3RPER application, or LMR36501P3RPER equivalent, key selection considerations include its 100-mA rated current, fixed 3.3-V output with ±1.5% accuracy in FPWM mode, precision EN/UVLO with 0.35-V hysteresis, PGOOD flag with 25-µs glitch filter, and thermal shutdown at 168°C with 10°C hysteresis.

Technical Context

The LMR36501P3RPER employs peak current mode control with internal compensation, enabling stable regulation with minimal external output capacitance. Its auto-mode operation dynamically transitions between PFM and FPWM based on load, optimizing efficiency across 0–100 mA.

It integrates a high-side MOSFET (2.2 Ω R_DS(on)) and low-side MOSFET (1 Ω R_DS(on)), supports boot capacitor recharging via V_BOOT-SW UVLO (2.3 V threshold), and features soft-start with 2.58-ms typical ramp time to 90% of V_REF. The RT pin enables precise external frequency programming without requiring an external clock source.

Key Specifications

Pinout & Package

LMR36501P3RPER uses the RPE package: 9-pin VQFN-HR (HotRod™), 2.00 mm × 2.00 mm body size, with wettable flank terminals and corner anchor pins for enhanced solder joint reliability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LMR36501P3RPER, LMR36501P5RPER offers identical performance at 5 V for logic compatibility, while LMR36502P3RPER provides 50% more output current in the same footprint - enabling design scalability without layout revision.

Availability

LMR36501P3RPER is available at Aetrix Electronics and suitable for factory automation sensors, building HVAC controllers, and portable power tool electronics requiring stable component supply, long-term industrial lifecycle support, and AEC-Q200-aligned reliability validation.

Supply support for LMR36501P3RPER 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 expertise in power management ICs for industrial, automotive, and consumer markets.

The LMR3650x product line was designed specifically for space-constrained, high-reliability industrial power supplies - emphasizing ultra-small footprint, wide input range, and robust thermal/EMI performance in harsh environments.

FAQ

What is the maximum input voltage the LMR36501P3RPER can withstand during transients?

The LMR36501P3RPER is rated to withstand input transients up to 70 V, exceeding its 65-V maximum continuous operating input voltage. This capability allows direct connection to industrial 24-V and 48-V bus lines without external transient voltage suppression in many applications. Absolute maximum rating for VIN to GND is 70 V, verified per TI's recommended operating conditions and absolute maximum ratings table.

Does the LMR36501P3RPER require external compensation components?

No, the LMR36501P3RPER uses peak current mode control with internal compensation, eliminating the need for external compensation networks. This simplifies design and reduces solution size - only input/output capacitors, an inductor, and optional RT resistor are required. The internal loop is optimized for stability with ≤10 µF total output capacitance, as confirmed in the device's Electrical Characteristics and Typical Applications sections.

How does the PGOOD function behave during startup and fault conditions for the LMR36501P3RPER?

The LMR36501P3RPER PGOOD pin asserts high after soft-start completes and output reaches 90% of target voltage, with a typical 2-ms delay (tPGOOD_ACT) and built-in 25-µs glitch filter. It goes low during EN deactivation, output undervoltage (<94% of 3.3 V), or overvoltage (>110% of 3.3 V). The open-drain output requires an external pull-up resistor and remains inactive during shutdown, ensuring clean system reset sequencing.

Can the LMR36501P3RPER operate with an input voltage below 3.6 V?

The LMR36501P3RPER has a minimum operating input voltage of 3.6 V (rising threshold) per recommended conditions, though its falling threshold is 3.0 V. Operation below 3.6 V is not guaranteed - the device may cease regulation or enter dropout. For sub-3.6-V inputs, consider alternative regulators such as the TPS630xx family. Startup will not occur if VIN rises below 3.4 V, as specified in the VIN_R parameter.

What is the thermal resistance (RθJA) of the LMR36501P3RPER package, and how does it impact thermal design?

The LMR36501P3RPER in its 2-mm × 2-mm VQFN-HR (RPE) package has a simulated RθJA of 85.7°C/W on a 4-layer JEDEC board. This value is for comparative analysis only and cannot be used for absolute thermal design. Real-world performance depends heavily on PCB copper area, layer stack-up, and airflow. TI recommends using the RθJB (28.0°C/W) and ΨJB (27.7°C/W) metrics for board-level thermal modeling, and confirms operation up to +150°C junction temperature with proper layout per Section 9.5 of the datasheet.