Monolithic Power Systems Inc. MPQ4473GL-AEC1-P

Overview

MPQ4473GL-AEC1-P from Monolithic Power Systems is an AEC-Q100 Grade 1 qualified, synchronous step-down DC/DC converter delivering 3.5A continuous output current with 4.5V–36V input range, 0.8V–0.9×VIN adjustable output, and 200kHz–1MHz programmable switching frequency. It integrates 40mΩ high-side and 20mΩ low-side MOSFETs, features proprietary switching-loss-reduction technology, and is deployed in automotive ADAS power rails and infotainment domain controllers.

For engineers reviewing the MPQ4473GL-AEC1-P datasheet, MPQ4473GL-AEC1-P pinout, MPQ4473GL-AEC1-P application, or MPQ4473GL-AEC1-P equivalent, key selection criteria include AEC-Q100 Grade 1 qualification, integrated FET R_DS(on) values, fast transient response under ±2A load steps, PGOOD timing (700μs delay), and bootstrap capacitor requirements for low-dropout operation.

Technical Context

The MPQ4473GL-AEC1-P employs a current-mode PWM control architecture with feed-forward input voltage compensation to maintain stable switching frequency across 4.5V–36V input. Its internal 5V LDO powers the bias circuitry and bootstrap regulator, enabling reliable high-side gate drive down to 0.8V output.

It implements cycle-by-cycle over-current protection with 100μs hiccup timer, thermal shutdown at 175°C (45°C hysteresis), and UVLO with 4.0V rising / 3.1V falling thresholds. The device supports both CCM and skip-mode operation, automatically transitioning at critical current (~1.2A typical) to sustain >85% efficiency from 1mA to 3.5A load.

Key Specifications

Pinout & Package

MPQ4473GL-AEC1-P is housed in a thermally enhanced 3mm × 4mm, 20-pin QFN package with exposed thermal pad (pins 8, 19, 21–25). The package supports ≤48°C/W junction-to-ambient thermal resistance on a 4-layer PCB per JESD51-7.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS543320RTWR and LM61480QRNRRQ1, MPQ4473GL-AEC1-P offers optimal balance of compact 3mm×4mm footprint, automotive qualification, and cost-sensitive BOM count - making it ideal for space-constrained ADAS and body electronics where 3.5A suffices and analog control simplicity is prioritized.

Availability

MPQ4473GL-AEC1-P is available at Aetrix Electronics and suitable for automotive ADAS camera systems, infotainment domain controllers, and industrial telematics gateways requiring stable component supply with AEC-Q100 assurance and long-term production continuity.

Supply support for MPQ4473GL-AEC1-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 MPQ4473 belongs to MPS's automotive-grade DC/DC converter product line, engineered specifically for demanding automotive subsystems requiring AEC-Q100 qualification, fast transient response, and high integration in minimal board space.

FAQ

What is the minimum recommended output capacitance for stable operation with ceramic capacitors?

The MPQ4473GL-AEC1-P requires ≥22μF total ceramic output capacitance with X5R/X7R dielectric for stable operation without external ramp compensation. For designs using POSCAPs, a minimum 12mΩ ESR is required to ensure inherent loop stability and eliminate need for external R4/C4 components.

Can the MPQ4473GL-AEC1-P operate in dropout mode, and what is the minimum input-to-output differential?

Yes - the device supports low-dropout operation via its bootstrap refresh circuitry. It maintains regulation with V_IN − V_OUT as low as 0.5V at light loads, and down to ~0.8V at full 3.5A load, provided the BST capacitor is properly sized (≥0.47μF) and routed with minimal loop inductance.

How does the frequency-setting resistor affect switching frequency accuracy and temperature drift?

The FREQ pin uses a current-source-based one-shot timer; switching frequency varies ±5% over temperature and input voltage when using standard 1% metal-film resistors. For tighter tolerance, use 0.1% resistor with <50ppm/°C TCR; frequency deviation remains within ±2% across −40°C to +125°C junction range.

What is the maximum allowable PCB trace length between BST and SW pins, and why is it critical?

Maximum recommended BST-to-SW trace length is 3mm with 0.2mm width and direct under-pad routing. Longer traces increase parasitic inductance, causing BST voltage undershoot during HS-FET turn-on, which may trigger premature high-side FET disable and reduce efficiency or cause instability at high duty cycles.

Does the MPQ4473GL-AEC1-P support forced continuous conduction mode (FCCM), and how is it enabled?

No - the MPQ4473GL-AEC1-P does not support FCCM. It operates in automatic PFM/PWM transition mode only. There is no pin or register to force CCM; light-load efficiency is optimized via skip-mode operation and current-modulator-controlled LS-FET discharge, eliminating audible noise and improving standby current.

What is the recommended input capacitor configuration for meeting CISPR 25 Class 5 conducted emissions?

Use a parallel combination of ≥10μF X5R ceramic (close to IN pins) and ≥47μF low-ESR tantalum or polymer capacitor (near bulk input). Place ferrite bead (600Ω @ 100MHz) between them. Layout must minimize high-di/dt loop area - keep IN-to-PGND path <5mm² and use solid ground plane beneath IC.

How does the internal current limit behave during thermal foldback, and is it latched?

The current limit remains active and non-latched during thermal foldback. When junction temperature exceeds 175°C, the device shuts down completely; upon cooling to 130°C, it initiates soft-start again. No current-limit reduction occurs before shutdown - OCP continues at nominal 4.2–9A threshold until thermal shutdown triggers.