Monolithic Power Systems Inc. MPQ4558DQ-AEC1-LF-P

Overview

MPQ4558DQ-AEC1-LF-P from Monolithic Power Systems is an AEC-Q100 Grade 1 qualified, non-synchronous step-down DC/DC converter with integrated 250mΩ high-side MOSFET, 3.8V–55V input range, 1A output current, and programmable 2MHz switching frequency. It delivers regulated output voltages from 0.8V to 52V using external resistor feedback and supports automotive power rail conditioning in engine control units and ADAS camera modules.

For engineers reviewing the MPQ4558DQ-AEC1-LF-P datasheet, MPQ4558DQ-AEC1-LF-P pinout, MPQ4558DQ-AEC1-LF-P application, or MPQ4558DQ-AEC1-LF-P equivalent, key selection criteria include its 12µA shutdown current for battery-backed systems, internal soft-start for controlled startup, thermal shutdown protection, and compatibility with ceramic output capacitors without external compensation components in basic configurations.

Technical Context

The MPQ4558DQ-AEC1-LF-P employs peak-current-mode control with a 140μA quiescent supply current and a 100ns minimum on-time, enabling stable operation at high duty cycles and fast transient response. Its error amplifier features 400V/V voltage gain and 120µA/V transconductance, with COMP pin clamping between 0.9V and 2.0V during regulation.

It integrates a programmable oscillator (set via FREQ pin resistor), internal 2.6V regulator for core logic, and bootstrap driver with UVLO (2.2V rising threshold). Frequency fold-back prevents inductor current runaway during startup, and short-circuit protection reduces current limit to ~50% when FB = 0V.

Key Specifications

Pinout & Package

MPQ4558DQ-AEC1-LF-P is housed in a thermally enhanced 10-pin QFN package (3mm × 3mm, 0.5mm pitch) with exposed thermal pad. The package supports high-power density designs and requires soldering of the exposed pad to PCB ground plane for optimal thermal performance (θ_JA = 50°C/W, 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 MPQ4558DQ-AEC1-LF-P, MPQ4571 offers higher current and broader input range but requires updated compensation; LM61480QRVCRQ1 provides greater output current but lacks 55V tolerance and Grade 1 certification, limiting use to lower-voltage automotive domains.

Availability

MPQ4558DQ-AEC1-LF-P is available at Aetrix Electronics and suitable for automotive power conversion, industrial telemetry, and battery-powered embedded systems requiring stable component supply and long-term lifecycle support.

Supply support for MPQ4558DQ-AEC1-LF-P 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 MPQ4558 belongs to MPS's automotive-grade DC/DC converter product line, engineered specifically for harsh-environment power management in engine compartments, ADAS, and infotainment systems where high input voltage tolerance and AEC-Q100 compliance are mandatory.

FAQ

What does "NOT RECOMMENDED FOR NEW DESIGNS" mean for MPQ4558DQ-AEC1-LF-P?

This designation indicates Monolithic Power Systems has released a functional successor (MPQ4571) with improved specifications and recommends it for all new projects. MPQ4558DQ-AEC1-LF-P remains fully supported for existing designs and continues to be manufactured and stocked per its published end-of-life schedule, with no immediate discontinuation planned.

Can MPQ4558DQ-AEC1-LF-P operate with input voltage below 3.8V?

No. The absolute minimum operating input voltage is 3.8V per the Recommended Operating Conditions table. Below this, the internal 2.6V regulator cannot sustain full functionality, and the device may fail to start or exhibit unstable regulation. For sub-3.8V applications, consider alternative converters such as the MPQ4569 series.

Why does the datasheet specify two different R_DS(on) values (175mΩ and 250mΩ)?

The 175mΩ value is typical at V_BST–V_SW = 5V and T_J = 25°C; the 250mΩ value is the maximum guaranteed across temperature and process variation. Designers must use 250mΩ for worst-case power loss and thermal calculations to ensure reliability at +125°C junction temperature.

Is an external bootstrap diode required for 2MHz operation?

Yes - at 2MHz, the minimum off-time (100ns) and reduced charging window may prevent full bootstrap capacitor recharge using only the internal circuit. An external Schottky diode (e.g., B290-13-F) from VIN to BST is recommended to ensure reliable high-side gate drive and prevent cycle skipping or dropout.

How does the MPQ4558 handle short-circuit conditions?

Under output short-circuit, the device activates frequency fold-back and reduces current limit to ~50% of nominal (≈0.65A). The soft-start voltage (SS) drops to ≈V_FB + 100mV, slowing recovery. Once the fault clears, output resumes ramping at the normal soft-start rate, preventing thermal stress and ensuring graceful fault recovery.

Does MPQ4558DQ-AEC1-LF-P support synchronous rectification?

No. It is a non-synchronous buck converter requiring an external Schottky diode for freewheeling current path. The SW pin drives only the internal high-side MOSFET; no low-side driver or control logic is integrated. Synchronous alternatives like MPQ4572 require separate external low-side FETs and drivers.