Monolithic Power Systems Inc. MPQ4345GLE-33-AEC1-Z

Overview

MPQ4345GLE-33-AEC1-Z from Monolithic Power Systems is an AEC-Q100 Grade 1 qualified synchronous step-down converter delivering up to 2A output at fixed 3.3V, with 3.3V–36V input range, 1μA shutdown current, and 350kHz–2.5MHz configurable switching frequency. It integrates 60mΩ high-side and 35mΩ low-side MOSFETs and supports automotive cold-crank (3.1V) and 42V load dump survival in clusters and ADAS power rails.

For engineers reviewing the MPQ4345GLE-33-AEC1-Z datasheet, MPQ4345GLE-33-AEC1-Z pinout, MPQ4345GLE-33-AEC1-Z application, or MPQ4345GLE-33-AEC1-Z equivalent, key selection criteria include its ultra-low quiescent current in sleep mode (3µA), AAM/FCCM mode flexibility, wettable-flank QFN-17 package for automotive solder-joint inspection, and integrated PG signal with ±6% window.

Technical Context

This buck regulator uses zero-delay PWM control with internal HS/LS FETs and supports both forced continuous conduction mode (FCCM) and advanced asynchronous modulation (AAM) for light-load efficiency optimization. Its 20ns minimum on-time enables high VIN-to-VOUT ratios, while symmetric VIN pinout and frequency spread spectrum reduce EMI.

The device implements thermal shutdown (150°C), over-current protection in hiccup mode, and low-dropout operation during cold-crank via high-duty-cycle capability. The open-drain PG output asserts when VOUT is within 94–106% of nominal, and SYNCIN/MODE pin selects between synchronization, FCCM, or AAM operation.

Key Specifications

Pinout & Package

MPQ4345GLE-33-AEC1-Z is housed in a wettable-flank QFN-17 (3mm × 4mm) package, enabling automated optical solder-joint inspection required for automotive production.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck converter applications.

Compared with MPQ4345GLE-33-AEC1-Z, the MPQ4345J variant offers identical regulation and protection but demands revised layout for its QFN-19 footprint, while the TPS62933RQNR lacks automotive qualification and input voltage headroom-making it unsuitable for direct replacement in AEC-Q100 designs.

Availability

MPQ4345GLE-33-AEC1-Z is available at Aetrix Electronics and suitable for automotive instrument clusters, ADAS camera modules, infotainment head units, and telematics control units requiring stable component supply with full AEC-Q100 traceability and long-term automotive lifecycle support.

Supply support for MPQ4345GLE-33-AEC1-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 power management ICs, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.

This device belongs to MPS's automotive-grade MPQ buck converter family, engineered specifically for harsh-environment DC-DC conversion in clusters, ADAS, and infotainment systems-emphasizing ultra-low IQ, AEC-Q100 compliance, and EMI robustness.

FAQ

What is the minimum input voltage required for MPQ4345GLE-33-AEC1-Z to regulate 3.3V output?

The device supports cold-crank operation down to 3.1V input while maintaining regulation, enabled by high-duty-cycle and low-dropout mode. Its UVLO rising threshold is 3.0V (typical), ensuring reliable startup even during battery sag. Below 3.1V, output drops linearly but remains functional until VIN falls below 2.8V, where UVLO disables the regulator.

Does MPQ4345GLE-33-AEC1-Z require an external feedback resistor network?

No. This part is a fixed 3.3V output variant; the feedback divider is internal. No external resistors are needed for regulation-only standard input/output capacitors, bootstrap capacitor, soft-start capacitor, and optional frequency-setting resistor are required per the reference design.

How does the AAM mode improve efficiency at light loads?

In AAM mode (SYNCIN/MODE pulled low), the controller skips pulses under light loads, reducing switching losses. Quiescent current drops to 3µA (typical), and efficiency at 1mA load exceeds 80%-significantly higher than FCCM mode, which sustains constant-frequency switching and draws ~1.2mA active current.

Can MPQ4345GLE-33-AEC1-Z synchronize to an external clock?

Yes. Driving a clean CMOS clock (90–115% of free-running frequency) into the SYNCIN/MODE pin forces the internal oscillator to lock, eliminating beat frequencies in multi-rail systems. The SYNCO pin outputs a buffered copy of the synchronized clock for cascading or measurement.

What is the purpose of the DNU pin, and how must it be handled?

Pin 14 is designated "Do Not Use" and has no internal connection. Per the datasheet, it must be tied directly to VCC (not left floating or grounded) to ensure proper internal biasing and avoid undefined behavior during startup or fault conditions.

Is the PG signal active-high or open-drain, and what pull-up is recommended?

PG is an open-drain output requiring an external pull-up resistor. A 10kΩ resistor to 3.3V or 5V is typical. PG asserts high when VOUT is within 94–106% of 3.3V and pulls low outside that window, with 50µs delay on both edges for noise immunity.

What thermal performance can be expected on a standard 4-layer PCB?

On an MPS EVB (2oz copper, 4-layer, 8.3cm × 8.3cm), θJA is 29.2°C/W. At 2A load and 12V input, case temperature rise is ~12°C above ambient-well within the 150°C junction limit. Derating begins above 100°C ambient unless enhanced copper pours or airflow are added.