Texas Instruments LMR36500P5RPER

Overview

LMR36500P5RPER from Texas Instruments is a 3-V to 65-V, 50-mA synchronous buck DC/DC converter in a 2-mm × 2-mm HotRod™ VQFN-HR package, featuring fixed 5-V output, precision EN/UVLO (1.263 V threshold), PGOOD with glitch filter, and adjustable switching frequency (200 kHz–2.2 MHz via RT pin). It delivers >80% peak efficiency at 1 MHz for 3.3-V output and supports rugged industrial applications including field transmitters and HVAC sensors.

For engineers reviewing the LMR36500P5RPER datasheet, LMR36500P5RPER pinout, LMR36500P5RPER application, or LMR36500P5RPER equivalent, key selection considerations include its 70-V input transient capability, –40°C to +150°C junction temperature range, internal compensation eliminating external loop components, ultra-small footprint, and functional safety documentation support.

Technical Context

The LMR36500P5RPER uses peak current mode control with internal compensation, enabling stable regulation with minimal output capacitance and eliminating external compensation networks. Its precision enable circuitry provides 0.35-V hysteresis and 1.263-V active threshold, allowing direct connection to VIN or precise external UVLO implementation.

It integrates a high-side MOSFET (5 Ω R_DS(on)) and low-side MOSFET (3.5 Ω R_DS(on)), supports auto-mode (PFM) and forced PWM operation, and features thermal shutdown (168°C trip) with 10°C hysteresis. The PGOOD flag includes built-in 25-µs glitch filtering and 1.956-ms delay-to-active timing for reliable system supervision.

Key Specifications

Pinout & Package

VQFN-HR (RPE) package: 9-pin, 2.0 mm × 2.0 mm body with wettable flank leads and corner anchor pads for enhanced solder joint reliability and automated optical inspection (AOI) compatibility.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LMR36500P5RPER, LMR36503P5RPER offers scalable current capacity without layout change, while TPS63020DSJR enables true buck-boost operation below 3 V but sacrifices 65-V robustness and industrial temperature rating.

Availability

LMR36500P5RPER is available at Aetrix Electronics and suitable for factory automation sensors, building HVAC controllers, and portable power tools requiring stable component supply, long-term manufacturability, and automotive-grade reliability under thermal stress.

Supply support for LMR36500P5RPER 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 power management technologies, with over 50 years of innovation in high-reliability power conversion ICs.

The LMR36500P5RPER belongs to TI's LMR365xx family of wide-input, low-I_Q buck converters designed specifically for space-constrained industrial and portable applications demanding ruggedness, efficiency, and simplified design.

FAQ

What is the maximum input voltage transient the LMR36500P5RPER can survive?

The LMR36500P5RPER is rated to withstand input voltage transients up to 70 V without damage or latch-up, exceeding its 65-V maximum operating input. This capability eliminates the need for external TVS diodes in many industrial 48-V DC bus applications, provided layout minimizes inductive kickback. Absolute maximum ratings specify VIN to GND as –0.3 V to +70 V, verified per JEDEC standards.

Does the LMR36500P5RPER require external compensation components?

No, the LMR36500P5RPER uses an internally compensated peak current mode control architecture optimized for stability with minimal output capacitance. No external compensation network (e.g., Type II/III RC networks) is required - simplifying layout, reducing BOM count, and accelerating design validation. This is confirmed in Section 7.1 and Figure 7-2 of the official SNVSC41 datasheet.

How does the PGOOD function behave during startup and fault conditions for the LMR36500P5RPER?

The LMR36500P5RPER PGOOD pin remains low during startup until output reaches 90% of target (after ~1.956 ms), then asserts high with built-in 25-µs glitch filtering. It pulls low instantly during overcurrent, thermal shutdown, or EN deactivation. When unused, PGOOD may be left open or grounded - no pullup is mandatory unless interfacing with logic that requires active-high signaling.

Can the LMR36500P5RPER operate with input voltage below 3.0 V?

No - the LMR36500P5RPER has a minimum operating input voltage of 3.0 V (falling threshold) and 3.6 V (rising threshold after startup). Below 3.0 V, the device ceases regulation and enters undervoltage lockout. For sub-3-V inputs such as single-cell Li-ion, a buck-boost solution like TPS63020DSJR is required instead of the LMR36500P5RPER.

What is the thermal performance of the LMR36500P5RPER in a standard 4-layer PCB layout?

In a JEDEC-standard 4-layer board, the LMR36500P5RPER exhibits a junction-to-ambient thermal resistance (R_θJA) of 85.7°C/W. On the LMR36500EVM evaluation board, this improves to 60°C/W. With 50-mA load and 24-V input, typical power dissipation is <150 mW, resulting in <10°C junction rise above ambient - well within its 150°C maximum rating even in sealed enclosures.