Monolithic Power Systems Inc. MP4560DN-LF

Overview

MP4560DN-LF from Monolithic Power Systems is a non-synchronous step-down DC/DC converter with integrated 250mΩ high-side 55V MOSFET, delivering up to 2A output current at up to 2MHz switching frequency across a 3.8V–55V input range and adjustable 0.8V–52V output. It features current-mode control, internal soft-start, and 140μA quiescent current-enabling use in automotive power rails and industrial distributed supplies.

For engineers reviewing the MP4560DN-LF datasheet, MP4560DN-LF pinout, MP4560DN-LF application, or MP4560DN-LF equivalent, key selection criteria include its 2MHz programmable frequency, 12µA shutdown current, thermal shutdown protection, frequency foldback during startup, and SOIC8E package with exposed pad for thermal management.

Technical Context

The MP4560DN-LF operates in fixed-frequency peak-current mode under moderate-to-heavy load and transitions to pulse-skipping mode at light loads to reduce switching losses. Its error amplifier compares FB voltage against a 0.8V reference and drives the COMP node to regulate inductor current via transconductance of 5.7A/V.

Bootstrap charging relies on an external capacitor between BST and SW pins, regulated to ~5V by an internal PMOS pass transistor; UVLO protection (2.2V rising threshold) prevents driver malfunction. EN pin enables positive-logic control with 1.55V rising threshold and 320mV hysteresis.

Key Specifications

Pinout & Package

MP4560DN-LF uses the SOIC8 with exposed pad (SOIC8E) package-8-pin surface-mount outline measuring 4.9mm × 6.0mm × 1.75mm, with thermal pad soldered to PCB ground plane for θ_JA = 50°C/W and θ_JC = 10°C/W performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP4560DN-LF, MP4572DN-LF offers lower quiescent current and better transient robustness for future designs, while LM5164QDGSRQ1 provides automotive qualification at the cost of design flexibility and reduced output capability.

Availability

MP4560DN-LF is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC power supplies, and battery-powered telematics requiring stable component supply through legacy production cycles.

Supply support for MP4560DN-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 over two decades of leadership in DC/DC conversion technology.

The MP4560 belongs to MPS's high-voltage buck converter product line, designed specifically for ruggedized power delivery in automotive, industrial, and telecom infrastructure where wide VIN, thermal resilience, and EMI control are critical.

FAQ

What is the maximum recommended output current for MP4560DN-LF in SOIC8E package at 85°C ambient?

The SOIC8E package has a θ_JA of 50°C/W. With 150°C max junction temperature and 85°C ambient, allowable power dissipation is 1.3W. At 12V input and 3.3V/2A output, conduction loss (~0.5W) plus switching loss (~0.4W) stays within limit-so 2A is sustainable with proper PCB copper area and airflow. Derate to 1.6A if ambient exceeds 85°C or copper area is minimal.

Can MP4560DN-LF operate with 3.3V input?

No. The absolute minimum operating input voltage is 3.8V per datasheet specifications. At 3.3V, the internal 2.6V regulator cannot sustain full functionality, and UVLO (rising threshold 3.0V) will prevent startup. For sub-3.8V inputs, consider MPS's MP2451 or MPQ4571 families.

Why does MP4560DN-LF require an external bootstrap diode at 2MHz operation?

At 2MHz, the off-time shrinks to ~500ns, reducing time available for bootstrap capacitor recharge via the internal PMOS. The internal charge path impedance becomes insufficient, risking BST voltage collapse and high-side FET failure. An external Schottky diode (e.g., B290-13-F) from VIN to BST ensures reliable charging independent of duty cycle.

Is MP4560DN-LF pin-compatible with MP4560DQ (QFN10) version?

No. MP4560DN-LF uses SOIC8E (8 pins), while MP4560DQ uses 3×3mm QFN10 (10 pins). Pin mapping differs significantly: QFN combines SW on Pins 1&2 and GND+exposed pad on Pin 6, whereas SOIC8E assigns SW to Pin 1 and GND to Pin 5. Layout and thermal design are not interchangeable.

Does MP4560DN-LF support synchronous rectification?

No. MP4560DN-LF is a non-synchronous buck converter requiring an external Schottky diode (e.g., CMSH2-100M) from SW to GND. It lacks a low-side FET driver or control logic for synchronous operation. For synchronous alternatives, see MPS's MPQ4470 or MPQ4420 series.

How does frequency foldback improve startup reliability?

During startup, inductor current ramps linearly. Without foldback, fixed 2MHz operation could cause peak current to exceed the 3.2A limit before feedback stabilizes. Foldback reduces frequency-extending off-time and limiting peak current-to prevent inductor saturation and thermal stress, especially with large output capacitors.

What is the purpose of the 100ns minimum on-time specification?

The 100ns minimum on-time limits the lowest achievable output voltage at high input voltages. For example, at VIN=55V and f_SW=2MHz (500ns period), the minimum duty cycle is 20%, setting V_OUT ≥11V. To achieve lower outputs (e.g., 3.3V), reduce f_SW via FREQ pin resistor or select a part with shorter min on-time like MP4572 (1.2A).