Monolithic Power Systems Inc. MP2565DN-LF-Z

Overview

MP2565DN-LF-Z from Monolithic Power Systems is a non-synchronous step-down DC/DC converter with integrated 220mΩ high-side MOSFET, delivering up to 2.5A output current across a 4.5V–50V input range. It operates at programmable switching frequencies up to 4MHz, features internal soft-start, 120μA quiescent current, and thermal shutdown protection. It is used in automotive power rails where wide VIN and EMI-sensitive environments (e.g., AM radio band) demand high-frequency operation.

For engineers reviewing the MP2565DN-LF-Z datasheet, MP2565DN-LF-Z pinout, MP2565DN-LF-Z application, or MP2565DN-LF-Z equivalent, this page provides verified technical context, package-specific pin functions, real-world application roles, and validated alternative options for industrial and automotive power design.

Technical Context

The MP2565 employs current-mode control with an internal error amplifier (200V/V gain, 60μA/V transconductance), enabling fast transient response and stable loop compensation via the COMP pin. Its programmable oscillator uses an external resistor on FREQ to set frequency from 1.6MHz to 4.8MHz, with foldback at light load to prevent inductor current runaway.

It integrates UVLO (3.0V rising threshold, 0.4V hysteresis), precision enable logic (1.5V rising, 1.2V falling thresholds), and a bootstrap driver regulated to ~5V for high-side gate drive. The internal 2.6V regulator powers control circuitry across full VIN range, and thermal shutdown activates at 150°C with 15°C hysteresis.

Key Specifications

Pinout & Package

MP2565DN-LF-Z is housed in a thermally enhanced SOIC-8 package with exposed pad (pin 5), which must be soldered to a PCB ground plane for thermal and electrical integrity. Pin numbering follows standard SOIC8 top-view orientation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2565DN-LF-Z, MP2451DJ-LF-Z trades output capability and thermal robustness for footprint reduction, while LM5164QPWPRQ1 adds automotive qualification and synchronous topology at higher BOM cost and design overhead - MP2565DN-LF-Z remains optimal for cost-sensitive, 2.5A industrial and Tier-2 automotive designs.

Availability

MP2565DN-LF-Z is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial PLC I/O modules, and smart sensor nodes requiring stable component supply across extended temperature and voltage ranges.

Supply support for MP2565DN-LF-Z 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 two decades of innovation in DC/DC conversion, motor drivers, and LED lighting controllers.

The MP2565 belongs to MPS's high-voltage buck converter product line, engineered for ruggedized power delivery in automotive, industrial, and telecom infrastructure where wide input range, high frequency, and thermal resilience are mandatory.

FAQ

What is the maximum allowable input voltage for MP2565DN-LF-Z?

The absolute maximum input voltage is +55V, but the recommended operating range is 4.5V to 50V. Operation above 50V risks exceeding internal MOSFET breakdown limits and may trigger UVLO or thermal shutdown. For sustained 50V operation, ensure SOIC8 thermal pad is fully soldered to ≥2 cm² copper area.

Can MP2565DN-LF-Z operate with 100% duty cycle?

No - MP2565DN-LF-Z cannot achieve 100% duty cycle due to minimum off-time limitation of 100ns and bootstrap charging requirement. When VIN ≈ VOUT, insufficient voltage headroom prevents BST capacitor recharge, causing high-side driver dropout. Minimum practical VOUT is ~0.8V at VIN ≥ 4.5V.

Is an external Schottky diode mandatory for MP2565DN-LF-Z?

Yes - MP2565DN-LF-Z is a non-synchronous buck converter and requires an external Schottky diode (e.g., B380-13-F) connected from SW to GND. Diode reverse voltage rating must exceed maximum VIN (e.g., ≥60V for 48V systems), and forward current rating must exceed peak inductor current (≥3.5A typical).

How does frequency foldback improve light-load efficiency?

At light loads, MP2565DN-LF-Z reduces switching frequency to lower gate-driving and switching losses - unlike fixed-frequency converters that waste energy pulsing at full rate. This foldback is automatic and preserves regulation accuracy while boosting efficiency from ~70% (at 10mA) to >85% (at 100mA) in typical 12V→3.3V designs.

What is the purpose of the exposed pad on the SOIC8 package?

The exposed pad (pin 5) serves dual thermal and electrical functions: it conducts heat from the die to the PCB ground plane (reducing θJA by ~10°C/W) and provides low-inductance return path for high-frequency switch currents. It must be soldered to a solid GND copper area - floating or undersized pads cause thermal derating and EMI issues.

Does MP2565DN-LF-Z support output voltages below 0.8V?

No - the internal feedback reference is fixed at 0.8V, and the device is not designed for sub-0.8V operation. Attempting to set VOUT < 0.8V violates the FB pin's operating range and causes regulation failure. For lower outputs, use an external reference or post-regulation LDO.

How is the COMP pin used for loop compensation?

COMP is the error amplifier output; a series RC network (e.g., 51kΩ + 220pF) between COMP and GND sets a dominant pole-zero pair to stabilize the current-mode loop. C3 places a zero to boost phase margin; optional C6 compensates ESR-related zeros in electrolytic/tantalum output caps - ceramic caps typically require only R3 and C3.