Monolithic Power Systems Inc. MP2365DN-LF

Overview

MP2365DN-LF from Monolithic Power Systems is a 1.4MHz synchronous step-down DC/DC converter with integrated 100mΩ high-side MOSFET, delivering 3A continuous output current across 4.75V–28V input range and adjustable 0.92V–21V output. It features current-mode control, cycle-by-cycle over-current protection, thermal shutdown, and programmable soft-start-used in industrial power rails and battery-powered systems requiring compact, efficient regulation.

For engineers reviewing the MP2365DN-LF datasheet, MP2365DN-LF pinout, MP2365DN-LF application, or MP2365DN-LF equivalent, key selection criteria include its fixed 1.4MHz switching frequency, 20μA shutdown current, 0.92V feedback reference, SOIC-8EP package with exposed pad, and compatibility with low-ESR ceramic output capacitors.

Technical Context

The MP2365DN-LF implements current-mode control using an internal transconductance error amplifier (G_EA = 330–730 µA/V) and slope-compensated current sensing (G_CS = 6.0 A/V), enabling fast transient response and stable loop compensation via the COMP pin. Its 1.4MHz oscillator sets switching timing, while short-circuit foldback reduces frequency to 180kHz under fault conditions.

It integrates a bootstrap gate driver for the high-side N-MOSFET, requiring external SW-to-BS capacitor (≥10nF); the BS pin supplies gate voltage above VIN. The EN pin provides digital enable/disable with 0.9V/2.9V thresholds and 210mV hysteresis, supporting automatic startup when left floating.

Key Specifications

Pinout & Package

MP2365DN-LF uses an 8-pin SOIC package with exposed thermal pad (SOIC-8EP, JEDEC MS-012 BA), where Pin 4 (GND) and the exposed pad must be electrically and thermally connected to the same PCB ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2365DN-LF, MP2365DN lacks documented Pb-free certification for export-sensitive programs, while MP2367DN-LF adds headroom for current scaling and lower VOUT but increases BOM cost without benefit in fixed 3.3V/5V applications.

Availability

MP2365DN-LF is available at Aetrix Electronics and suitable for industrial power rails, battery-powered test equipment, automotive body control modules, and distributed telecom power requiring stable component supply, RoHS compliance, and long-lifecycle support.

Supply support for MP2365DN-LF 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 manufacturing partnerships.

The MP2365 belongs to MPS's high-frequency buck converter product line, engineered for space-constrained, efficiency-critical applications such as industrial automation, telecom infrastructure, and portable electronics where minimal external components and robust fault protection are essential.

FAQ

What is the minimum recommended input capacitance for MP2365DN-LF?

The datasheet specifies a 10µF ceramic capacitor (C1) at the IN pin for typical operation. For 3A loads, a parallel combination of 10µF X5R MLCC plus a 0.1µF C0G ceramic placed directly at the IN-GND pins is recommended to suppress high-frequency switching noise and ensure stable operation across the 4.75–28V input range.

Can MP2365DN-LF operate with 100% duty cycle?

No. The MP2365DN-LF has a maximum duty cycle of 65%, enforced internally when FB voltage drops below 0.8V. This limitation prevents shoot-through and ensures reliable high-side gate drive under low-VIN/high-VOUT conditions, making it unsuitable for applications requiring dropout operation near VIN ≈ VOUT.

Is an external bootstrap diode required for MP2365DN-LF?

An external bootstrap diode (e.g., IN4148) is optional and recommended only when VOUT ≥ 3.3V and duty cycle exceeds 65% (i.e., VOUT/VIN > 0.65). It improves high-side gate drive efficiency under heavy load or low-input-voltage conditions but is not required for standard 5V-out-from-12V operation.

How is thermal performance affected by the exposed pad connection?

The exposed pad must be soldered to a minimum 100mm² copper area connected to Pin 4 (GND) to achieve the specified θ_JA = 50°C/W. Without this, junction temperature can exceed 150°C at 3A load, triggering thermal shutdown. Vias under the pad (≥4×0.3mm) are strongly recommended for multilayer boards.

What compensation components are needed for a 3.3V/3A design?

Per Table 3 in the datasheet, a 3.3V output with 4.7µH inductor and dual 22µF ceramic output capacitors uses R3 = 15kΩ and C3 = 5.6nF. No C6 is required unless the output capacitor ESR zero falls below 700kHz; ceramic caps typically omit C6 due to negligible ESR.

Does MP2365DN-LF support forced PWM or PFM mode selection?

No. MP2365DN-LF operates exclusively in forced continuous conduction mode (CCM) at fixed 1.4MHz. It does not feature pulse-frequency modulation (PFM) or mode-select pins. Light-load efficiency is maintained via low 20µA shutdown current and optimized gate drive, not variable-frequency operation.

What is the purpose of the "OPEN" jumper on EV2365DN-00A evaluation board?

The "OPEN" jumper on the EV2365DN-00A board disconnects the EN pin from pull-up, enabling automatic startup when IN is applied. When closed, it connects EN to VIN through a resistor, allowing manual enable control or integration into system power sequencing logic.