Monolithic Power Systems Inc. MPQ4409GQBE-AEC1-P

Overview

MPQ4409GQBE-AEC1-P from Monolithic Power Systems is an AEC-Q100 Grade 1 qualified, synchronous step-down DC/DC converter delivering 900mA continuous output current from a 4V–24V input, with fixed 2.2MHz switching frequency, integrated 90mΩ/50mΩ MOSFETs, and Power Good (PG) indicator - deployed in automotive infotainment power rails.

For engineers reviewing the MPQ4409GQBE-AEC1-P datasheet, MPQ4409GQBE-AEC1-P pinout, MPQ4409GQBE-AEC1-P application, or MPQ4409GQBE-AEC1-P equivalent, key selection criteria include AEC-Q100 qualification, forced CCM operation for low-light-load ripple, valley-current OCP with hiccup mode, CISPR25 Class 5 EMI compliance, and wettable flank QFN-13 package for automated optical inspection.

Technical Context

The MPQ4409GQBE-AEC1-P employs peak current-mode control with internal compensation, enabling stable regulation across 0.807V–VIN×0.85 output range while maintaining fixed-frequency operation via forced continuous conduction mode (FCCM) from no load to full load. Its valley-current detection OCP and thermal shutdown (170°C trip, 30°C hysteresis) provide robust fault handling in automotive environments.

It integrates a 4.9V internal bias regulator powered from VIN, bootstrap charging circuitry with 20Ω BST resistor recommendation, and EN/SYNC pin supporting both enable control and external clock synchronization from 450kHz to 2.2MHz - all within a thermally enhanced QFN-13 (2.5mm×3mm) wettable flank package rated for −40°C to +125°C junction temperature.

Key Specifications

Pinout & Package

MPQ4409GQBE-AEC1-P uses a QFN-13 (2.5mm × 3mm) wettable flank package with exposed thermal pad (PGND-connected), optimized for automotive reflow and AOI inspection. Pin 1 is marked by laser etch or corner chamfer per JEDEC MO-220.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS62903RTER and LM61480QRNRRQ1, MPQ4409GQBE-AEC1-P uniquely balances AEC-Q100 Grade 1 compliance, wettable flank inspection readiness, and minimal 2.5mm×3mm footprint for 900mA automotive PoL - making it optimal where qualification, manufacturability, and size are jointly constrained.

Availability

MPQ4409GQBE-AEC1-P is available at Aetrix Electronics and suitable for automotive infotainment, instrument clusters, and telematics systems requiring stable component supply with full AEC-Q100 traceability and PPAP support.

Supply support for MPQ4409GQBE-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 power management ICs, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MPQ4409 belongs to MPS's automotive-grade DC/DC converter product line, engineered specifically for AEC-Q100-compliant power delivery in infotainment, cluster, and ADAS subsystems where reliability, EMI performance, and compact layout are essential.

FAQ

What is the purpose of the BST pin and why is a 20Ω resistor recommended?

The BST pin supplies gate drive voltage to the high-side MOSFET via a bootstrap capacitor charged from the SW node. A 20Ω resistor between SW and BST dampens ringing and reduces voltage spikes during switching transitions, preventing false triggering of the bootstrap UVLO and improving long-term reliability - especially critical in automotive vibration environments.

Does MPQ4409GQBE-AEC1-P support adjustable output voltage, and what is the minimum achievable value?

Yes, output voltage is set externally via a resistor divider on the FB pin. The internal reference is 807mV ±12mV, enabling outputs as low as 0.807V. For example, a 5V output uses R_FB1 = 41.2kΩ and R_FB2 = 7.68kΩ; lower voltages require proportionally scaled resistors while maintaining ~40kΩ total for stability.

How does the Power Good (PG) signal behave during startup and fault conditions?

PG is an open-drain output pulled low until V_FB reaches 88% of the target (e.g., 4.4V for 5V), then rises after a 30–160μs delay. It falls again if V_FB drops to 83% of target, or immediately upon EN/SYNC deactivation, thermal shutdown, or output short - providing deterministic system-level fault signaling.

What distinguishes forced CCM mode from pulse-skipping or DCM in MPQ4409GQBE-AEC1-P?

Forced CCM maintains constant 2.2MHz switching regardless of load - unlike DCM which skips cycles at light loads. This eliminates low-frequency output ripple and audible noise, improves transient response predictability, and simplifies EMI filter design, making it ideal for noise-sensitive automotive digital loads.

Is external soft-start capacitor required, and how is startup timing controlled?

No external soft-start capacitor is needed. MPQ4409GQBE-AEC1-P features internal soft-start with fixed 0.45–3ms ramp time (typ. 1.5ms), during which the internal reference voltage gradually rises from 0V to 807mV - controlling output voltage slew rate and preventing inrush current without additional components.

What PCB layout practices are critical for thermal performance in QFN-13 package?

Maximize thermal dissipation by connecting the exposed PGND pad to a large internal ground plane using ≥6 thermal vias (0.3mm diameter, 0.6mm pitch), minimize trace resistance on IN/PGND/SW paths, and avoid splitting the PGND plane beneath the IC - these practices reduce θ_JA from 60°C/W (JESD51-7) to ~42°C/W (EVB), enabling full 900mA at 125°C ambient.