Monolithic Power Systems Inc. MP2565DQ-LF-P

Overview

MP2565DQ-LF-P from Monolithic Power Systems is a 2.5A, 4MHz, 50V non-synchronous step-down DC/DC converter with integrated 220mΩ high-side MOSFET, 120µA quiescent current, and programmable switching frequency (up to 4MHz via external resistor). It delivers stable 3.3V output in automotive power rails and industrial distributed supplies using ceramic output capacitors.

For engineers reviewing the MP2565DQ-LF-P datasheet, MP2565DQ-LF-P pinout, MP2565DQ-LF-P application, or MP2565DQ-LF-P equivalent, key selection criteria include its 4.5–50V input range, internal soft-start, thermal shutdown protection, and compatibility with compact 3×3mm QFN10 layout for EMI-sensitive AM radio and ADSL systems.

Technical Context

The MP2565DQ-LF-P employs current-mode control with an internal error amplifier (200V/V gain, 60µA/V transconductance) and cycle-by-cycle peak current limiting set by COMP voltage. Its programmable oscillator uses an external resistor on FREQ pin to set switching frequency from 1.6MHz to 4.8MHz.

It integrates a bootstrap driver for the high-side MOSFET, requiring a BST-to-SW capacitor; UVLO thresholds are 2.7–3.3V (rising) with 0.4V hysteresis, and thermal shutdown activates at 150°C with 15°C hysteresis. The device operates in frequency foldback mode at light load to maintain >90% efficiency down to 10mA.

Key Specifications

Pinout & Package

MP2565DQ-LF-P is housed in a thermally enhanced 3mm × 3mm, 10-pin QFN package with exposed thermal pad (connected to GND). The package supports ≤2.5W power dissipation at +25°C ambient and features 50°C/W junction-to-ambient thermal resistance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down converter applications.

Compared with LM5164QPWPRQ1 and TPS54260DGQR, MP2565DQ-LF-P uniquely combines 50V rating, 2.5A output, 4MHz programmability, and integrated MOSFET in a 3×3mm QFN-enabling smaller footprints, faster transient response, and simpler BOMs in automotive and telecom point-of-load designs.

Availability

MP2565DQ-LF-P is available at Aetrix Electronics and suitable for automotive infotainment power, industrial PLC I/O modules, and battery-powered telematics requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MP2565DQ-LF-P 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

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance analog and power ICs, with over 20 years of expertise in DC/DC conversion, motor drivers, and LED lighting controllers.

The MP2565 belongs to MPS's high-voltage buck converter product line, engineered specifically for automotive, industrial, and telecom applications demanding wide input range, high frequency, and minimal external components.

FAQ

What is the minimum recommended input voltage for reliable startup?

The MP2565DQ-LF-P has a VIN UVLO rising threshold of 2.7–3.3V with 0.4V hysteresis. Reliable startup occurs at ≥3.0V; below this, the internal 2.6V regulator cannot sustain full functionality. For battery-powered systems, ensure input remains above 3.0V during cold-crank or discharge events.

Can the MP2565DQ-LF-P operate without an external bootstrap diode?

Yes-the MP2565DQ-LF-P integrates a bootstrap regulator that charges the BST capacitor directly from VIN through an internal PMOS transistor. No external diode is required unless operating at >90% duty cycle, where external charging assistance may be needed to maintain BST voltage above 2.2V.

How does frequency foldback improve light-load efficiency?

At light loads, the MP2565DQ-LF-P reduces switching frequency to lower gate-driving and switching losses. This dynamic scaling maintains >85% efficiency at 10mA output-critical for always-on systems-while avoiding the audible noise and instability associated with pulse-skipping modes.

What is the maximum allowable output voltage, and how is it set?

The MP2565DQ-LF-P supports output voltages up to 47V, set by the FB divider ratio: V_OUT = 0.8V × (1 + R1/R2). For 47V, R1/R2 ≈ 57.75; use R2 = 10kΩ and R1 = 578kΩ (1% tolerance). Ensure feedback resistors have ≤0.1% TCR for precision regulation across temperature.

Is the exposed thermal pad electrically connected internally?

Yes-the exposed pad on the MP2565DQ-LF-P QFN package is internally connected to GND. It must be soldered to a dedicated PCB ground plane with ≥4 thermal vias (0.3mm diameter) to achieve specified θ_JA = 50°C/W and prevent thermal shutdown under 2.5A continuous load.

Does the COMP pin require external components for basic operation?

Yes-a series RC network (e.g., 51kΩ + 220pF) is mandatory on COMP for loop stability. The error amplifier's 200V/V gain and 60µA/V transconductance interact with output impedance; omitting compensation causes oscillation or slow transient response, especially with ceramic output capacitors.

What is the purpose of the FREQ pin resistor tolerance impact?

FREQ pin resistor tolerance directly affects switching frequency accuracy: a 1% resistor yields ±1.5% f_SW variation. For EMI-sensitive applications, use 0.5% metal-film resistors and place them close to the pin to minimize parasitic capacitance that could shift frequency by up to 5%.