Monolithic Power Systems Inc. MP4560DQ-LF-Z

Overview

MP4560DQ-LF-Z 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 2MHz switching frequency across 3.8V–55V input range. It features 0.8V feedback reference, 140μA quiescent current, and internal soft-start-designed for automotive and industrial power conversion where wide VIN and compact footprint are critical.

For engineers reviewing the MP4560DQ-LF-Z datasheet, MP4560DQ-LF-Z pinout, MP4560DQ-LF-Z application, or MP4560DQ-LF-Z equivalent, key selection criteria include its programmable 2MHz oscillator (via FREQ pin), bootstrap capacitor charging constraints at high duty cycles, thermal shutdown threshold of 150°C, and mandatory external Schottky diode for output rectification.

Technical Context

The MP4560DQ-LF-Z implements peak current-mode control with cycle-by-cycle current limiting and frequency foldback during startup or short-circuit events. Its error amplifier delivers 400V/V gain and 120µA/V transconductance, with COMP pin clamped between 0.9V and 2.0V during regulation.

It uses a floating high-side gate driver powered by an internal bootstrap regulator that maintains ~5V between BST and SW pins; the driver includes UVLO (2.2V rising threshold, 150mV hysteresis) and resets soft-start if bootstrap voltage drops below threshold. Minimum on/off times are both 100ns, limiting practical duty cycle range at 2MHz operation.

Key Specifications

Pinout & Package

MP4560DQ-LF-Z is housed in a thermally enhanced 3mm × 3mm, 10-pin QFN package with exposed thermal pad (pin 5). The exposed pad must be soldered to a dedicated GND plane for optimal thermal performance (θ_JC = 12°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP4560DQ-LF-Z, MP4572DN-LF-Z offers synchronous operation and higher current, while LM5164QPWPRQ1 adds automotive qualification and diagnostics - both require PCB layout revision due to different pinouts and thermal pad configurations.

Availability

MP4560DQ-LF-Z is available at Aetrix Electronics and suitable for automotive front-end power, industrial 24V/48V distribution, and battery-powered telematics requiring stable component supply through extended product lifecycle phases.

Supply support for MP4560DQ-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 core expertise in DC/DC conversion, motor drivers, and LED lighting controllers.

The MP4560 belongs to MPS's high-voltage buck converter product line, engineered for rugged industrial and automotive environments where wide input range, thermal resilience, and compact integration are essential design requirements.

FAQ

What is the recommended external Schottky diode for MP4560DQ-LF-Z?

Use a Schottky diode rated ≥55V reverse voltage and ≥2.5A average current, such as Diodes Inc. B290-13-F (90V/2A) or Central Semiconductor CMSH3-100MA (100V/3A). The diode must be placed within 3mm of SW and GND pins to minimize parasitic inductance and ringing.

Can MP4560DQ-LF-Z operate at 2MHz without external bootstrap assistance?

No - at 2MHz and high duty cycles (>70%), the internal bootstrap charging time becomes insufficient. An external bootstrap diode (e.g., 1N4148W) from VIN to BST is strongly recommended to ensure reliable high-side gate drive and prevent dropout.

Why does MP4560DQ-LF-Z specify "NOT RECOMMENDED FOR NEW DESIGNS"?

MPS has superseded MP4560 with MP4572, which integrates a synchronous rectifier, improves efficiency by eliminating external diode losses, increases output current to 3A, and reduces solution size. MP4560 remains available for legacy support but lacks newer features and long-term roadmap alignment.

How is thermal performance affected by the QFN10 exposed pad connection?

Thermal resistance θ_JA drops from 50°C/W (no pad solder) to 50°C/W (with pad) only if the exposed pad is fully soldered to a ≥2cm² internal GND plane with ≥4 thermal vias. Without proper pad connection, junction temperature can exceed 150°C at 2A load, triggering thermal shutdown.

What compensation components are needed for a 3.3V/2A output using 10µH inductor and 22µF ceramic output cap?

Per MPS Application Note AN-4560, use R3 = 68.1kΩ, C3 = 220pF, and C6 = 2pF. These values target ~200kHz crossover frequency (1/10 of 2MHz), provide >60° phase margin, and stabilize the current-mode loop with ceramic output capacitance.

Does MP4560DQ-LF-Z support output voltages below 0.8V?

No - the internal 0.8V feedback reference is fixed and not adjustable. Output voltage is calculated as V_OUT = 0.8V × (1 + R1/R2); minimum achievable V_OUT is therefore constrained by resistor tolerance and FB pin bias current error, typically not below 0.82V in practice.

Is MP4560DQ-LF-Z RoHS compliant and lead-free?

Yes - the "-LF" suffix confirms lead-free, RoHS-compliant packaging. All MPS products adhere to EU RoHS Directive 2011/65/EU and are halogen-free per IEC 61249-2-21. Full compliance documentation is available on the MPS Quality Assurance page.