Monolithic Power Systems Inc. MPQ2178GQHE-8-AEC1-Z

Overview

MPQ2178GQHE-8-AEC1-Z from Monolithic Power Systems is an AEC-Q100 Grade 1 qualified synchronous step-down DC/DC converter delivering 2A continuous output at fixed 0.8V, operating from 2.5V–6V input, featuring 2.4MHz switching frequency, integrated 70mΩ/40mΩ MOSFETs, and power-good (PG) with soft-start control. It targets automotive infotainment, clusters, and telematics power rails where compact size, EMI robustness, and junction temperature operation up to +150°C are critical.

For engineers reviewing the MPQ2178GQHE-8-AEC1-Z datasheet, MPQ2178GQHE-8-AEC1-Z pinout, MPQ2178GQHE-8-AEC1-Z application, or MPQ2178GQHE-8-AEC1-Z equivalent, key selection criteria include its fixed 0.8V output accuracy (±1%), wettable-flank QFN-8 package for solder-joint inspection, FCCM mode for low-noise light-load operation, and MPSafe™ QM functional safety documentation support.

Technical Context

The MPQ2178GQHE-8-AEC1-Z employs constant-on-time (COT) control with VIN feed-forward to maintain stable 2.4MHz switching across 2.5V–6V input and full load range, enabling fast transient response without external compensation. Its internal P-channel (70mΩ) and N-channel (40mΩ) MOSFETs eliminate external power switches while supporting 100% duty cycle for ultra-low dropout.

Fault protection includes cycle-by-cycle current limiting (PCH peak: 3.5A, NCH valley: 2A), thermal shutdown at 170°C with 20°C hysteresis, output over-voltage protection (115% VFB), short-circuit hiccup mode, and PG monitoring with 90% VFB rising threshold and 85% falling threshold - all validated for automotive ambient conditions (-40°C to +150°C).

Key Specifications

Pinout & Package

MPQ2178GQHE-8-AEC1-Z is housed in a wettable-flank QFN-8 package (1.5mm × 2mm, 0.5mm pitch), optimized for automated optical inspection (AOI) of solder joints and high-density automotive PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ2178GQHE-8-AEC1-Z, MPQ2177GQHE-8-AEC1-Z trades 0.5A output and 0.9MHz frequency for lower cost and thermal footprint, while TPS6286418RTER offers higher frequency but sacrifices automotive-grade thermal range and built-in PG functionality.

Availability

MPQ2178GQHE-8-AEC1-Z is available at Aetrix Electronics and suitable for automotive infotainment systems, ADAS camera modules, and digital instrument clusters requiring stable component supply with AEC-Q100 compliance and long-term production continuity.

Supply support for MPQ2178GQHE-8-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 a focus on efficiency, integration, and automotive-grade reliability.

The MPQ2178 belongs to MPS's automotive-qualified DC/DC converter product line, designed specifically for demanding automotive subsystems requiring AEC-Q100 qualification, extended temperature operation, and functional safety documentation support.

FAQ

What is the purpose of the SS pin on MPQ2178GQHE-8-AEC1-Z?

The SS (soft-start) pin controls the ramp-up time of the output voltage during power-on. For this fixed-0.8V variant, it sources a 16µA current to an external capacitor (CSS ≥ 5.3nF), setting tSS ≥ 2ms to limit inrush current and prevent output overshoot - critical for protecting downstream logic and ensuring clean system boot.

Can the FB pin be left unconnected on MPQ2178GQHE-8-AEC1-Z?

Yes. As a fixed 0.8V output version, the FB pin is internally connected to the precision resistor divider and requires no external components. Leaving it floating is the recommended configuration per the datasheet - connecting external resistors would disrupt regulation and cause output error.

Does MPQ2178GQHE-8-AEC1-Z support pre-biased start-up?

Yes. The device safely starts up even when the output capacitor is pre-charged to 0.8V or higher. Internal circuitry prevents reverse current flow from the output into the switch node, eliminating risk of damage or bus contention during hot-plug or multi-rail sequencing scenarios.

How does the PG pin function, and what external components are needed?

PG is an open-drain output that goes high (via external pull-up resistor to 3V–6V) when VFB reaches ≥90% of 0.6V (i.e., ≥0.54V), and low when VFB falls ≤85% (≤0.51V). A typical 100kΩ pull-up resistor provides sufficient drive strength while minimizing quiescent current in automotive always-on domains.

What thermal derating guidance applies for MPQ2178GQHE-8-AEC1-Z at 125°C ambient?

At TA = 125°C, maximum continuous output current drops to ~1.3A assuming θJA = 130°C/W and TJ(MAX) = 150°C. Derating is calculated as IOUT(max) = √[(TJ(MAX) − TA)/θJA × RDS(ON)_P] - users must verify PCB copper area, airflow, and thermal vias to sustain target load under worst-case ambient conditions.

Is output discharge active when EN is pulled low?

Yes. When EN is driven below 0.65V, the device enters shutdown and activates an internal discharge MOSFET between OUT and GND (RDIS ≈ 150Ω), safely bleeding stored energy from the output capacitor within milliseconds - essential for meeting automotive safety requirements during power-down sequences.

What distinguishes the "wettable flank" feature in the QFN-8 package?

The wettable flank design exposes vertical copper sidewalls on all eight leads, enabling automated optical inspection (AOI) of solder fillets during reflow. This eliminates X-ray inspection needs for automotive production, improves first-pass yield, and supports IPC-A-610 Class 3 acceptance criteria for mission-critical vehicle electronics.