Monolithic Power Systems Inc. MPQ4321CGLE-AEC1-Z

Overview

MPQ4321CGLE-AEC1-Z from Monolithic Power Systems is an AEC-Q100 Grade 1 qualified synchronous step-down converter with integrated 70mΩ/50mΩ HS/LS MOSFETs, 3.3V–36V input range, 42V load dump tolerance, and configurable 350kHz–2.5MHz switching frequency. It delivers up to 1A continuous output current with 1μA shutdown current and operates across –40°C to +150°C junction temperature for automotive infotainment, clusters, and ADAS power rails.

For engineers reviewing the MPQ4321CGLE-AEC1-Z datasheet, MPQ4321CGLE-AEC1-Z pinout, MPQ4321CGLE-AEC1-Z application, or MPQ4321CGLE-AEC1-Z equivalent, key selection considerations include cold-crank support (3.1V min VIN), power-good accuracy (±5.5% window), FSS modulation for CISPR25 Class 5 compliance, wettable flank QFN-12 (3mm×4mm) package, and thermal shutdown at 175°C.

Technical Context

The MPQ4321CGLE-AEC1-Z uses peak current mode control with frequency foldback during start-up to prevent inductor current runaway. Its dual-VIN pin architecture enables symmetric layout for reduced EMI, while MeshConnect™ flip-chip packaging improves thermal resistance (θJA = 50°C/W).

It supports forced CCM and low-dropout (LDO) mode for automotive cold-crank conditions, and integrates open-drain PG with 94.5%–105.5% output voltage monitoring. The FREQ pin accepts external resistor programming (86.6kΩ → 415kHz; 15kΩ → 2.2MHz), and internal protection includes over-current hiccup mode, thermal shutdown (175°C), and 42V transient tolerance per ISO16750.

Key Specifications

Pinout & Package

MPQ4321CGLE-AEC1-Z is housed in a wettable flank QFN-12 (3mm × 4mm) package with exposed thermal pad. Pin numbering follows top-view orientation as defined in MPS datasheet Rev. 1.1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4321CGDE-AEC1-Z, the MPQ4321CGLE-AEC1-Z offers 17% lower θJA for improved thermal headroom in 3mm×4mm footprint; versus MPQ4321CGRHE-AEC1-Z, it trades 2 pins and 0.2mm width for simpler routing and identical wettable flank AOI capability.

Availability

MPQ4321CGLE-AEC1-Z is available at Aetrix Electronics and suitable for automotive infotainment systems, instrument clusters, ADAS sensors, and industrial HMIs requiring stable component supply with AEC-Q100 Grade 1 assurance and wettable flank manufacturability.

Supply support for MPQ4321CGLE-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 for automotive, industrial, cloud computing, and consumer markets.

The MPQ4321C product line delivers ultra-compact, AEC-Q100-qualified buck converters optimized for automotive subsystems demanding high efficiency, low EMI, and extreme environmental resilience.

FAQ

What is the minimum input voltage required to start up the MPQ4321CGLE-AEC1-Z?

The device requires a minimum VIN of 3.9V to initiate startup due to its UVLO rising threshold of 3.65V (typical). Once running, it sustains regulation down to 3.1V-critical for automotive cold-crank operation where battery voltage dips below 6V.

How does the FREQ pin configure switching frequency, and what resistor values are supported?

The FREQ pin sets fSW by connecting an external resistor to AGND. Valid range is 10kΩ to 100kΩ: 86.6kΩ yields 415kHz, 34.8kΩ yields 1MHz, and 15kΩ yields 2.2MHz. Resistor tolerance directly impacts frequency accuracy; 1% metal film is recommended for ±5% fSW control.

Does MPQ4321CGLE-AEC1-Z support adjustable output voltage, and what is the FB reference voltage?

Yes-it supports both fixed-output (e.g., 5V) and adjustable configurations. The FB pin has a precision reference of 0.800V (±0.75% over temperature), enabling output voltages from 0.8V up to 0.95×VIN using external resistive dividers.

What protection features are integrated, and how do they behave under fault conditions?

Integrated protections include cycle-by-cycle over-current (hiccup mode), thermal shutdown (175°C, 20°C hysteresis), input over-voltage lockout (37.5V typ), and undervoltage lockout. During over-current, the device enters hiccup mode-shutting down for ~3ms before retrying-to limit power dissipation and prevent thermal runaway.

Is the MPQ4321CGLE-AEC1-Z pin-compatible with other MPQ4321C variants?

Yes-MPQ4321CGLE-AEC1-Z shares identical pinout and functionality with MPQ4321CGDE-AEC1-Z and MPQ4321CGRHE-AEC1-Z. Only package dimensions and thermal characteristics differ; no schematic or layout changes are needed when upgrading from QFN-12 (2×3mm) to QFN-12 (3×4mm).

What is the purpose of the dual VIN pins, and how should they be routed?

The dual VIN pins (pins 2 and 10) provide symmetrical high-current input paths to reduce parasitic inductance and improve EMI performance. They must be routed with equal-length, low-inductance traces to a common bulk capacitor, and each requires its own local 100nF ceramic decoupling capacitor to PGND placed as close as possible to the pin.

How does the power-good (PG) signal behave during startup and fault conditions?

PG remains low until VOUT reaches 94.5% of target and stays within ±5.5% window. If VOUT exceeds 107% or drops below 93%, PG pulls low with 70µs rising and 60µs falling deglitch timing. During soft-start, PG asserts only after tSS (~5ms) completes and regulation is confirmed.