Monolithic Power Systems Inc. MP2403DN-LF-P

Overview

MP2403DN-LF-P from Monolithic Power Systems is a monolithic synchronous step-down DC/DC converter integrating 150mΩ high-side and 80mΩ low-side MOSFETs, delivering 3A continuous output current across 4.6V–32V input range, with fixed 250kHz switching frequency and 0.80V feedback reference-used in notebook computers and distributed power systems for compact, efficient voltage regulation.

For engineers reviewing the MP2403DN-LF-P datasheet, MP2403DN-LF-P pinout, MP2403DN-LF-P application, or MP2403DN-LF-P equivalent, key selection criteria include its integrated power stage, thermal performance in SOIC8N-EP package, soft-start programmability via external capacitor, cycle-by-cycle overcurrent protection, and compatibility with low-ESR ceramic output capacitors.

Technical Context

The MP2403DN-LF-P employs current-mode control architecture with internal transconductance error amplifier (820μA/V typ), COMP pin-based loop compensation, and fixed-frequency oscillator (250kHz ±15% over temperature). It features built-in UVLO (3.95V threshold), OVP latch (0.95V FB trip), and thermal shutdown at 160°C.

Its functional block includes a 5V internal regulator powering the high-side gate driver, bootstrap capacitor charging path from SW to BS, and dual current-limit thresholds: upper switch limit of 4.3–5.3A and lower switch limit of 1.25A, enabling robust overload handling without external sensing.

Key Specifications

Pinout & Package

MP2403DN-LF-P uses an 8-pin SOIC package with exposed thermal pad (SOIC8N-EP), requiring direct connection of the exposed pad and Pin 4 (GND) to a common ground plane for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2403DN-LF-P, MP2451DT-LF-Z offers higher frequency and voltage margin but lower current capacity, while LM5115MTCX/NOPB provides scalable power and wider input range at the cost of increased design complexity and component count.

Availability

MP2403DN-LF-P is available at Aetrix Electronics and suitable for notebook computer power supplies, distributed power pre-regulators, and embedded controller power rails requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP2403DN-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, and global distribution through authorized partners.

The MP2403 belongs to MPS's integrated synchronous buck converter product line, engineered for compact, high-efficiency DC/DC conversion in space-constrained applications where minimal external components and thermal robustness are critical.

FAQ

What is the minimum recommended output capacitance for stable operation?

The MP2403DN-LF-P is stable with as little as 22μF ceramic output capacitance when paired with appropriate compensation (e.g., 5.6kΩ/3.3nF for 3.3V output). Lower values may cause instability or excessive ripple; use X5R/X7R dielectrics and place capacitor within 5mm of FB and GND pins.

Can the MP2403DN-LF-P operate with input voltage below 4.6V?

No - the device has a hard UVLO threshold of 3.95V (typical), and guaranteed operation begins only at 4.6V. Below this, the IC remains disabled; attempting to force operation risks erratic behavior or failure to regulate due to insufficient gate drive voltage for internal MOSFETs.

Is an external Schottky diode required for basic operation?

No - the MP2403DN-LF-P integrates both high- and low-side MOSFETs and operates synchronously without external diodes. An optional Schottky (e.g., B340) may improve efficiency by ~1–2% at light loads by bypassing the low-side MOSFET body diode conduction loss.

How does the exposed thermal pad affect PCB layout?

The exposed pad must be soldered to a dedicated thermal pad on the PCB, connected directly to the main GND plane with ≥4 thermal vias (0.3mm diameter) to inner ground layers. Insufficient copper area (<10.7mm²) or missing vias causes junction temperature to exceed 125°C at 3A, triggering thermal shutdown.

What happens during output short-circuit condition?

Under short-circuit, the MP2403DN-LF-P enters frequency foldback mode (55kHz), reducing switching frequency to limit power dissipation. It maintains hiccup-mode restart attempts until fault clears; no latch-off occurs, and recovery is automatic once short is removed.

Does the COMP pin require mandatory external components?

Yes - a series RC network (e.g., 5.6kΩ + 3.3nF) from COMP to GND is required for stability. Omitting it causes oscillation or poor transient response. For ceramic output caps, C6 is typically unnecessary; for aluminum or SP-CAP, add C6 (e.g., 100pF) per Table 3 in datasheet Rev.1.0.

What is the maximum achievable output voltage?

The MP2403DN-LF-P supports up to 28V output, limited by the 35V absolute maximum rating on the SW pin and internal OVP threshold (0.95V at FB). At 28V output, the FB divider ratio requires R1 ≈ 340kΩ with R2 = 10kΩ; ensure resistor power rating exceeds 100mW under worst-case conditions.