Monolithic Power Systems Inc. MPQ4460DQ-LF-Z

Overview

MPQ4460DQ-LF-Z from Monolithic Power Systems is an industrial-grade, non-synchronous step-down DC/DC converter with integrated 150mΩ high-side MOSFET, delivering up to 2.5A output current across a 3.8V–36V input range, programmable 4MHz switching frequency, and 0.8V–30V adjustable output voltage-designed for automotive power rails and battery-powered industrial systems.

For engineers reviewing the MPQ4460DQ-LF-Z datasheet, MPQ4460DQ-LF-Z pinout, MPQ4460DQ-LF-Z application, or MPQ4460DQ-LF-Z equivalent, key selection criteria include its 120µA quiescent current for low-power operation, internal soft-start and thermal shutdown, frequency foldback for startup reliability, and QFN10 (3mm × 3mm) package compatibility with high-density PCB layouts.

Technical Context

The MPQ4460DQ-LF-Z implements peak current-mode control with an internal error amplifier (200V/V gain, 60µA/V transconductance), enabling fast transient response and simplified loop compensation via the COMP pin. Its programmable oscillator uses an external resistor on FREQ to set switching frequency from 0.2MHz to 4MHz.

It features internal UVLO (3.0V rising threshold, 0.35V hysteresis), precision enable logic (1.5V rising, 1.2V falling thresholds), and bootstrap-driven high-side gate control with dedicated 5V BST regulator. Thermal shutdown activates at 150°C with 15°C hysteresis, ensuring fault-tolerant operation under overload or poor heatsinking.

Key Specifications

Pinout & Package

MPQ4460DQ-LF-Z is housed in a thermally enhanced 3mm × 3mm QFN10 package with exposed thermal pad on the underside for PCB-level heat dissipation. Pin numbering follows standard top-view orientation with Pin 1 at top-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4460DQ-LF-Z, MP2451DT-LF-Z trades programmability and current headroom for simplicity, while LM5164QPWPRQ1 adds automotive qualification and higher VIN tolerance at the expense of output current and cost-making MPQ4460DQ-LF-Z optimal for industrial and cost-sensitive automotive non-safety applications requiring 2.5A and 4MHz flexibility.

Availability

MPQ4460DQ-LF-Z is available at Aetrix Electronics and suitable for automotive infotainment power, industrial PLC I/O modules, and battery-powered test equipment requiring stable component supply across extended temperature and long product lifecycles.

Supply support for MPQ4460DQ-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, and global manufacturing partnerships.

The MPQ4460 belongs to MPS's industrial-grade DC/DC converter product line, engineered for rugged operation in automotive, factory automation, and distributed power systems where wide input range, high efficiency, and thermal resilience are mandatory.

FAQ

What is the minimum recommended input voltage for reliable startup?

The MPQ4460DQ-LF-Z has a guaranteed UVLO rising threshold of 3.0V with 0.35V hysteresis. Reliable startup occurs at VIN ≥ 3.45V; operation below 3.0V disables regulation, and the device remains latched off until VIN exceeds 3.45V. For 3.7V Li-ion applications, this ensures functional operation across the full discharge curve.

Can the MPQ4460DQ-LF-Z operate without an external bootstrap diode?

Yes-the MPQ4460DQ-LF-Z integrates a bootstrap charging circuit that uses the internal high-side switch node (SW) and VIN to charge the BST capacitor. No external bootstrap diode is required, unlike many competing controllers. The internal circuit regulates BST to ~5V and includes UVLO (2.2V) to prevent driver malfunction.

How does frequency foldback improve light-load efficiency?

At light loads, the MPQ4460DQ-LF-Z reduces switching frequency to lower gate-driving and switching losses. This dynamic scaling maintains >85% efficiency down to 10mA output current-critical for battery-powered devices in standby mode-without requiring pulse-skipping or burst-mode control that increases output ripple.

What is the maximum allowable output voltage ripple with ceramic output capacitors?

With a 22µF X5R ceramic capacitor and 10µH inductor at 4MHz, typical peak-to-peak output ripple is <15mV for a 3.3V/2A output. Ripple is dominated by capacitive impedance at high frequency; the MPQ4460DQ-LF-Z's current-mode architecture and 0.8V reference ensure tight regulation even with low-ESR ceramics.

Is the exposed thermal pad electrically connected internally?

No-the exposed pad on the QFN10 package is a thermal pad only and is not connected to any internal circuitry. It must be soldered to a large PCB copper pour tied to GND for optimal thermal performance (θ_JA = 50°C/W). Electrical isolation prevents short circuits if the pad contacts adjacent traces.

Does the MPQ4460DQ-LF-Z support synchronous rectification?

No-it is a non-synchronous buck converter requiring an external Schottky diode (e.g., B340A-13-F) connected between SW and GND. Synchronous operation is not supported; the internal MOSFET is high-side only, and no low-side driver or control logic is included.

What is the recommended layout practice for the COMP pin?

The COMP pin must be routed away from noisy nodes (SW, VIN, BST) and kept short (<5mm). Its RC compensation network (e.g., 68.1kΩ + 220pF for 3.3V output) should be placed directly at the pin with ground plane underneath. Avoid vias or stubs-COMP is high-impedance and sensitive to parasitic capacitance that degrades phase margin.