Monolithic Power Systems Inc. MP28254EL-LF-P

Overview

MP28254EL-LF-P from Monolithic Power Systems is a synchronous step-down DC/DC converter IC with integrated 120mΩ high-side and 20mΩ low-side MOSFETs, delivering up to 4A continuous output current across a 4.5V–21V input range, fixed 500kHz switching frequency, and adjustable output voltage down to 0.805V - deployed in notebook I/O power and flat-panel display bias rails.

For engineers reviewing the MP28254EL-LF-P datasheet, MP28254EL-LF-P pinout, MP28254EL-LF-P application, or MP28254EL-LF-P equivalent, key selection criteria include internal MOSFET R_DS(on), thermal shutdown at 150°C, EN/SYNC dual-function pin behavior, and QFN14 package layout constraints for high-current SW and GND routing.

Technical Context

The MP28254 operates in peak current-mode control with internal compensation, enabling stable regulation without external loop components. Its proprietary switching loss reduction technique and integrated bootstrap diode support efficient high-duty-cycle operation up to 90%.

It features a dual-role EN/SYNC pin that accepts CMOS/TTL logic for enable/disable control or 300kHz–2MHz external clock synchronization, while the open-drain PG pin asserts low when FB falls below 0.85×V_FB, providing precise power-good monitoring tied to the 0.805V reference.

Key Specifications

Pinout & Package

MP28254EL-LF-P is housed in a thermally enhanced 3mm × 4mm, 14-pin QFN package with exposed thermal pad (no internal electrical connection), requiring PCB copper area and multiple vias for optimal heat dissipation and low-impedance GND return.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP28254EL-LF-P, MP2384 offers higher current capability and newer process technology, while RT7295BGJ8F demands additional external components and layout changes - making MP2384 the preferred upgrade path for performance and longevity.

Availability

MP28254EL-LF-P is available at Aetrix Electronics and suitable for notebook I/O power, flat-panel display bias, and networking subsystems requiring stable component supply despite its "Not Recommended for New Designs" status.

Supply support for MP28254EL-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 design centers in the US, China, and Taiwan.

The MP28254 belongs to MPS's high-density DC/DC converter product line, engineered for space-constrained computing and consumer electronics where integration, thermal performance, and fast transient response are critical.

FAQ

What does "NOT RECOMMENDED FOR NEW DESIGNS" mean for MP28254EL-LF-P?

This designation indicates MPS has superseded the MP28254 with the MP2384, which offers higher current, improved efficiency, and extended lifetime support. MP28254 remains fully functional and available for existing designs and legacy production, but new projects should evaluate MP2384 for long-term supply assurance and technical advantages.

Can MP28254EL-LF-P operate with input voltage below 4.5V?

No - the absolute minimum operating input voltage is 4.5V per datasheet specifications. Below this, UVLO prevents startup, and internal VCC regulation fails. The 3.8V–4.2V UVLO rising threshold ensures reliable turn-on only within the validated 4.5V–21V range.

How is the 0.805V feedback reference used to set output voltage?

V_OUT = 0.805V × (1 + R1/R2), where R1 connects from V_OUT to FB and R2 connects from FB to GND. For example, 1.2V output uses R1 = 4.99kΩ and R2 = 10.2kΩ. The T-network is recommended for outputs ≤1.5V to minimize resistor sensitivity.

Why does MP28254 have four separate GND pins and an exposed pad?

The four GND pins plus exposed thermal pad provide low-impedance return paths for high-frequency switch-node currents and thermal conduction. This configuration reduces ground bounce, improves EMI performance, and lowers junction temperature by up to 25°C compared to single-GND layouts.

Is external bootstrap diode required for MP28254EL-LF-P?

No - the device integrates a bootstrap diode. An external diode (e.g., IN4148) is optional and only beneficial when duty cycle exceeds 65% (e.g., V_IN/V_OUT > 1.5), improving efficiency by reducing BST capacitor charging losses.

What happens during thermal shutdown, and how does recovery work?

At 150°C, the IC disables switching and pulls PG low. It remains off until die temperature falls to ~140°C, then automatically resumes operation. This hysteresis prevents oscillation near the threshold and protects against sustained overheating in poorly ventilated enclosures.

How does the EN/SYNC pin function in synchronization mode?

When an external clock (300kHz–2MHz) is applied, the internal oscillator locks to its rising edge within 2ms. The chip maintains phase alignment while preserving internal soft-start and fault protection - enabling deterministic EMI reduction across multi-rail systems.