Monolithic Power Systems Inc. MP2365DN-LF-Z

Overview

MP2365DN-LF-Z from Monolithic Power Systems is a 3A, 28V input, 1.4MHz synchronous step-down DC/DC converter with integrated 100mΩ high-side MOSFET and 10Ω low-side switch. It delivers adjustable output voltage from 0.92V to 21V, supports 4.75–28V input range, and features cycle-by-cycle over-current protection and thermal shutdown. Used in battery chargers and pre-regulators for linear regulators.

For engineers reviewing the MP2365DN-LF-Z datasheet, MP2365DN-LF-Z pinout, MP2365DN-LF-Z application, or MP2365DN-LF-Z equivalent, key selection criteria include its 3A continuous output capability, 1.4MHz fixed switching frequency, 20μA shutdown current, and SOIC-8EP package with exposed pad for thermal management.

Technical Context

The MP2365DN-LF-Z employs current-mode control architecture with internal transconductance error amplifier (G_EA = 330–730 µA/V) and slope-compensated current sensing (G_CS = 6.0 A/V). Its 1.4MHz oscillator enables compact filter design while maintaining stability across wide load and line variations.

It integrates a bootstrap gate driver (BS pin) requiring external SW-to-BS capacitor for high-side N-MOSFET drive, and uses an internal 10Ω low-side switch to charge the bootstrap capacitor during SW low phase. Feedback regulation occurs at 0.92V reference on FB pin with ±2.8% tolerance over temperature and line.

Key Specifications

Pinout & Package

MP2365DN-LF-Z is housed in an 8-pin SOIC package with exposed thermal pad (SOIC-8EP, JEDEC MS-012 BA), where the exposed pad must be soldered to Pin 4 (GND) for optimal thermal performance (θ_JA = 50°C/W, θ_JC = 10°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2365DN-LF-Z, MP2365DN-LF offers identical performance in cut-tape form but lacks tape-and-reel compatibility, while RT7272BGJ6F trades higher integration and frequency for reduced feature set and larger passive components-making MP2365DN-LF-Z optimal for compact, high-efficiency 3A POL designs.

Availability

MP2365DN-LF-Z is available at Aetrix Electronics and suitable for battery chargers, distributed power rails, and pre-regulator circuits requiring stable component supply, RoHS-compliant packaging, and long-term industrial availability.

Supply support for MP2365DN-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 design centers in the US, China, and Taiwan.

The MP2365 product line targets high-efficiency, high-density DC/DC conversion for industrial, computing, and automotive applications-emphasizing integration, thermal robustness, and ease of layout in SOIC-8EP packages.

FAQ

What is the minimum recommended input voltage for reliable startup?

The MP2365DN-LF-Z requires ≥4.75V at the IN pin to initiate regulation. Below this, the under-voltage lockout prevents operation-even if EN is asserted-ensuring clean startup behavior across temperature and process variation. Startup is guaranteed at 4.75V with full 3A load capability.

Can the MP2365DN-LF-Z operate without an external bootstrap capacitor?

No. The BS pin requires a minimum 10nF ceramic capacitor connected between BS and SW to charge the high-side MOSFET gate driver. Omitting it causes immediate failure of high-side switching, resulting in no output voltage and potential thermal overstress on the low-side switch.

How does the soft-start function interact with the EN pin?

When EN is pulled high (>2.9V), the internal soft-start circuit begins charging the SS pin's external capacitor, ramping FB reference voltage linearly over the programmed time (e.g., 5ms with 0.1µF). If EN is toggled during soft-start, the ramp resets-preventing output overshoot during re-enable sequences.

Is the exposed thermal pad electrically isolated from internal circuitry?

No. The exposed pad is internally connected to Pin 4 (GND) and must be soldered directly to the PCB's GND plane. This dual-purpose connection provides both low-thermal-resistance heat transfer and low-inductance ground return-critical for stable current-mode operation and EMI control.

What output capacitor ESR range is supported for stable operation?

The MP2365DN-LF-Z is optimized for ceramic capacitors (ESR <10mΩ), but supports tantalum and low-ESR electrolytics (up to 50mΩ) with appropriate compensation. For ESR >20mΩ, adding C6 (second compensation cap) per datasheet Table 3 is mandatory to avoid loop instability at light loads.

Does the MP2365DN-LF-Z support forced PWM or power-save mode?

No. It operates exclusively in forced continuous conduction mode (CCM) at 1.4MHz. There is no pulse-skipping or discontinuous mode-ensuring constant switching frequency for predictable EMI filtering, but with slightly higher light-load quiescent current than adaptive-mode converters.

What is the maximum achievable output voltage accuracy over temperature and line?

With properly selected feedback resistors (0.1% tolerance, 25ppm/°C), output voltage accuracy is ±1.5% over –40°C to +85°C ambient and full input range (4.75–28V), dominated by the 0.92V FB reference tolerance (±2.8%) and resistor divider drift.