Monolithic Power Systems Inc. MP28265EL-LF-P

Overview

MP28265EL-LF-P from Monolithic Power Systems is a synchronous step-down DC-DC converter with integrated 120mΩ high-side and 20mΩ low-side MOSFETs, delivering 5A continuous output current across a 4.5V–21V input range. It operates at a fixed 1.1MHz switching frequency with internal compensation, supports external clock synchronization (400kHz–2MHz), and provides power-good indication and thermal shutdown-used in notebook I/O power rails where compact size and high efficiency at light-to-full load are critical.

For engineers reviewing the MP28265EL-LF-P datasheet, MP28265EL-LF-P pinout, MP28265EL-LF-P application, or MP28265EL-LF-P equivalent, key selection criteria include its QFN3x4-14 package thermal performance (θJA = 48°C/W), 0.8V adjustable output voltage reference tolerance (±1.7%), cycle-by-cycle over-current protection with hiccup mode, and bootstrap capacitor-driven high-side gate drive requiring SW–BST connection.

Technical Context

The MP28265EL-LF-P employs peak-current-mode control with an internal 1.1MHz oscillator and fold-back frequency reduction below 500mV FB voltage to improve short-circuit robustness. Its error amplifier compares FB against a trimmed 805mV reference and drives an internal compensation network that eliminates external Type-II/III components.

It integrates a 5V VCC regulator powered from VIN, a floating high-side driver with bootstrap UVLO (2.2V threshold), and open-drain PG output with 0.7×VFB/0.9×VFB hysteresis. EN/SYNC serves dual function: digital enable control (1.3V typical rising threshold) and external clock input for frequency synchronization.

Key Specifications

Pinout & Package

MP28265EL-LF-P is housed in a thermally enhanced 3mm × 4mm QFN-14 package with an exposed copper thermal pad on the underside (pin 10 and exposed pad). The package supports reflow soldering per JEDEC J-STD-020 and requires PCB land pattern per MPS specification (3.2mm × 3.4mm thermal pad, 0.5mm pitch).

Key Features

Applications

Equivalent & Alternatives

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

Compared with RT7290BZSP and TPS54560QDGQRQ1, MP28265EL-LF-P delivers superior integration (internal compensation, hiccup OCP, 3×4mm footprint) for cost-sensitive, thermally constrained 5A loads under 21V, while offering tighter FB reference accuracy and lower solution footprint.

Availability

MP28265EL-LF-P is available at Aetrix Electronics and suitable for notebook systems, networking equipment, digital set-top boxes, and flat-panel display power designs requiring stable component supply, RoHS-compliant packaging, and long-term production continuity.

Supply support for MP28265EL-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 mixed-signal ICs for power management, motion control, and automotive applications.

The MP28265 belongs to MPS's high-frequency synchronous buck converter product line, designed specifically for compact, high-efficiency point-of-load regulation in portable and space-constrained computing systems.

FAQ

What is the maximum allowable input voltage for MP28265EL-LF-P?

The absolute maximum input voltage is 22V, but the recommended operating range is 4.5V to 21V. Exceeding 21V risks violating the 23V absolute maximum rating on the SW pin during startup or transients, potentially damaging the internal high-side MOSFET.

Can MP28265EL-LF-P operate without an external bootstrap capacitor?

No. A 0.1µF ceramic capacitor between BST and SW pins is mandatory to generate the floating gate drive voltage for the high-side MOSFET. Omitting it prevents high-side conduction and causes immediate functional failure.

How does the PG pin behave during startup and fault conditions?

PG asserts high-Z (open-drain) only when FB reaches ≥90% of its target voltage; it pulls low when FB falls ≤70%. During soft-start or output short, PG remains low until regulation is re-established, enabling reliable power sequencing in multi-rail systems.

Is external compensation required for stable operation?

No. MP28265EL-LF-P includes fully optimized internal compensation. External compensation components are unnecessary and would destabilize the control loop. The device achieves phase margin >60° with standard 1µH inductor and 47µF ceramic output capacitor.

What thermal derating applies above 85°C ambient temperature?

At TA = 85°C, maximum continuous output current drops to ~3.8A due to thermal limiting. Derating follows PD_MAX = (150°C − TA)/48°C/W; at TA = 100°C, usable power drops to ~1.04W, limiting practical output to <2A with standard PCB layout.

Does MP28265EL-LF-P support forced PWM or power-save mode?

No. It operates exclusively in peak-current-mode PWM without pulse-skipping or discontinuous conduction mode. Light-load efficiency is maintained via low quiescent current (0.7mA) and optimized MOSFET R_DS(on), not mode switching.

What is the purpose of the separate AGND and GND pins?

AGND isolates the analog feedback and error amplifier reference from high-current power ground noise. It must be connected to the main GND plane at a single point near the IC to prevent FB sensing errors and ensure regulation accuracy within ±1.7%.