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

Overview

MPQ2178GQHE-8-AEC1-P from Monolithic Power Systems is an AEC-Q100 Grade 1 qualified, synchronous step-down DC/DC converter delivering 2A continuous output current across a 2.5V–6V input range, with fixed 0.8V output, 2.4MHz switching frequency, integrated power MOSFETs (70mΩ PCH / 40mΩ NCH), and power-good (PG) + soft-start (SS) functions. It targets automotive infotainment, camera modules, and clusters where compact size, EMC robustness, and junction temperature operation up to +150°C are critical.

For engineers reviewing the MPQ2178GQHE-8-AEC1-P datasheet, MPQ2178GQHE-8-AEC1-P pinout, MPQ2178GQHE-8-AEC1-P application, or MPQ2178GQHE-8-AEC1-P equivalent, key selection criteria include its wettable-flank QFN-8 (1.5mm×2mm) package, COT control architecture for fast transient response, FCCM operation across full load, and integrated output discharge and over-voltage protection.

Technical Context

The MPQ2178GQHE-8-AEC1-P employs constant-on-time (COT) control with VIN feed-forward to maintain stable 2.4MHz switching across input and load variations, enabling fast line/load transient response without external compensation. Its internal 0.6V reference and fixed 0.8V output eliminate external feedback resistors.

It integrates complementary P-channel (70mΩ) and N-channel (40mΩ) MOSFETs, supports 100% duty cycle for low-dropout operation, and features programmable soft-start via external capacitor on SS pin (16µA charge current for 0.8V variant), plus open-drain PG with 90% VREF rising threshold and 85% falling threshold.

Key Specifications

Pinout & Package

MPQ2178GQHE-8-AEC1-P is housed in a thermally enhanced, wettable-flank QFN-8 package (1.5mm × 2mm, 0.5mm pitch), optimized for automotive PCB assembly and thermal dissipation (θJA = 59°C/W on 4-layer EV board).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS62840DLCR and RTQ2134BGQW, MPQ2178GQHE-8-AEC1-P uniquely combines 2A capacity, dedicated SS pin, open-drain PG, wettable-flank QFN-8, and full AEC-Q100 Grade 1 qualification - making it optimal for production automotive SoC core rails demanding integrated sequencing and reliability.

Availability

MPQ2178GQHE-8-AEC1-P is available at Aetrix Electronics and suitable for automotive infotainment systems, ADAS camera modules, instrument clusters, and telematics control units requiring stable component supply with full AEC-Q100 traceability and long-term lifecycle support.

Supply support for MPQ2178GQHE-8-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 over two decades of leadership in DC/DC converters, motor drivers, and LED controllers.

The MPQ2178 belongs to MPS's automotive-grade MPQ series, designed specifically for AEC-Q100-compliant power conversion in infotainment, ADAS, and body electronics - emphasizing thermal robustness, EMC resilience, and functional safety readiness.

FAQ

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

The SS (soft-start) pin accepts an external capacitor to control the output voltage ramp rate during startup, preventing inrush current and overshoot. For this 0.8V fixed-output variant, the internal SS charge current is 16µA; a minimum 5.3nF capacitor yields ~0.33ms soft-start time. The pin must be connected to GND via the capacitor - floating it disables soft-start and risks current surge.

Does MPQ2178GQHE-8-AEC1-P require external feedback resistors?

No. As a fixed 0.8V output variant, MPQ2178GQHE-8-AEC1-P integrates the feedback resistor divider internally. The FB pin is left unconnected (floating) in standard operation. This eliminates layout sensitivity, reduces BOM count, and improves regulation accuracy versus adjustable versions using external resistors.

How does the PG (power good) signal behave during undervoltage events?

PG is an open-drain output pulled high when FB voltage exceeds 90% of the 0.6V internal reference (i.e., ≥540mV). If FB drops below 85% of VREF (≤510mV), PG is actively pulled low. During brown-out or start-up, PG remains low until regulation is established, providing a clean enable signal for downstream logic or sequencers.

Can MPQ2178GQHE-8-AEC1-P operate with 100% duty cycle?

Yes. The device supports 100% duty cycle operation in dropout mode, allowing VOUT to track VIN down to within ~0.5V. This is critical for automotive applications during cold-crank (VIN ≈ 2.5V) where maintaining 0.8V output requires maximum conduction time without pulse skipping or discontinuous mode instability.

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

On the EVQ2178-QH-00A evaluation board (6.3cm×6.3cm, 2oz copper, 4-layer), θJA is 59°C/W. At 2A load and 5V input, typical power loss is ~0.35W, resulting in ~21°C junction-to-ambient rise above ambient. With proper thermal vias under the exposed pad, sustained operation at TJ = 125°C is achievable at full load in +85°C ambient.

Is output discharge active during shutdown?

Yes. When EN is pulled low, the device activates an internal discharge FET between OUT and GND, discharging the output capacitor through a ~150Ω path. This prevents residual voltage from interfering with downstream logic states or causing latch-up. Discharge is automatic and requires no external components.

What distinguishes the "-AEC1" suffix from standard MPQ2178 variants?

The "-AEC1" suffix denotes full AEC-Q100 Grade 1 qualification (–40°C to +125°C ambient, +150°C junction), including stress testing, failure analysis, and certified lot traceability. It also indicates wettable-flank packaging and MPSafe™ QM documentation - mandatory for safety-critical automotive power rails.