Monolithic Power Systems Inc. MPQ2178GQHE-18-AEC1-Z

Overview

MPQ2178GQHE-18-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 1.8V from a 2.5V–6V input. It integrates 70mΩ P-channel and 40mΩ N-channel MOSFETs, employs constant-on-time (COT) control with VIN feed-forward for stable 2.4MHz switching, and includes power good (PG), soft start (SS), output discharge, and hiccup-mode short-circuit protection-designed for automotive infotainment and cluster power rails.

For engineers reviewing the MPQ2178GQHE-18-AEC1-Z datasheet, MPQ2178GQHE-18-AEC1-Z pinout, MPQ2178GQHE-18-AEC1-Z application, or MPQ2178GQHE-18-AEC1-Z equivalent, this page delivers verified electrical specs, QFN-8 (1.5mm×2mm) terminal mapping, automotive-grade thermal performance (−40°C to +150°C), FCCM operation, and EMI-optimized MeshConnect™ flip-chip packaging per CISPR25 Class 5.

Technical Context

The MPQ2178GQHE-18-AEC1-Z implements a COT control architecture with VIN feed-forward to maintain tight frequency stability (2.4MHz ±10%) across 2.5V–6V input and full load range, eliminating external compensation. Its internal 0.6V reference and fixed 1.8V output (±2% tolerance) are achieved via factory-trimmed resistor divider, rendering FB pin unused in this variant.

Fault management includes cycle-by-cycle current limiting (PCH peak: 3.5A typ, NCH valley: 2A typ), thermal shutdown at 170°C with 20°C hysteresis, output over-voltage protection (115% VFB), and robust PG monitoring with 90% rising/85% falling thresholds referenced to internal VREF-enabling precise rail sequencing in safety-critical automotive subsystems.

Key Specifications

Pinout & Package

MPQ2178GQHE-18-AEC1-Z is housed in a wettable flank QFN-8 package (1.5mm × 2mm, 0.5mm pitch), optimized for automated optical inspection (AOI) and high-reliability solder joint formation in automotive PCB assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ2178GQHE-18-AEC1-Z, the MPQ2177 offers cost savings at reduced current capability and missing discharge, while the TPS6286418RTER trades automotive reliability for size and frequency-making the MPQ2178 the sole choice for thermally demanding, safety-critical 2A automotive rails.

Availability

MPQ2178GQHE-18-AEC1-Z is available at Aetrix Electronics and suitable for automotive infotainment systems, instrument clusters, and telematics control units requiring stable component supply, AEC-Q100 compliance, and long-term production continuity.

Supply support for MPQ2178GQHE-18-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.

The MPQ2178 belongs to MPS's automotive-grade MPQ series, engineered specifically for harsh-environment DC/DC conversion in infotainment, ADAS, and body electronics-emphasizing AEC-Q100 qualification, functional safety readiness, and EMI robustness.

FAQ

Can MPQ2178GQHE-18-AEC1-Z operate with input voltage below 2.5V?

No. The device features an under-voltage lockout (UVLO) with a rising threshold of 2.45V and hysteresis of 200mV. Operation below 2.3V disables the IC, and sustained input below 2.5V violates the recommended operating condition. This ensures stable startup and prevents erratic regulation during automotive cold-crank events.

Is the FB pin required for this fixed-output variant?

No. For MPQ2178GQHE-18-AEC1-Z, the feedback divider is internal and factory-trimmed for 1.8V output. The FB pin must be left unconnected (floating) to avoid interference with regulation. Connecting it externally will cause undefined behavior or failure to regulate correctly.

What is the purpose of the wettable flank package?

The wettable flank QFN-8 exposes solderable sidewalls on all eight leads, enabling automated optical inspection (AOI) of solder fillets during SMT reflow. This significantly improves process yield and field reliability in automotive manufacturing, where zero-defect solder joints are mandatory per IATF 16949.

Does the device support pre-biased start-up?

Yes. MPQ2178GQHE-18-AEC1-Z supports pre-biased start-up: when EN is asserted, the internal control loop actively regulates even if the OUT pin already holds a voltage near 1.8V. This prevents reverse current flow and ensures glitch-free power sequencing in multi-rail systems.

How is output discharge implemented and controlled?

Upon EN deactivation, an internal NMOS transistor connects OUT to GND through a 150Ω discharge path, safely bleeding stored energy from the output capacitor. Discharge can be disabled by placing a capacitor (e.g., 10nF) between VOUT and OUT-useful when powering circuits that must retain state during brief power interruptions.

What thermal derating applies at 100°C ambient?

With θJA = 59°C/W on the EVQ2178-QH-00A evaluation board, maximum allowable power dissipation at TA = 100°C is PD(MAX) = (150°C − 100°C) / 59°C/W ≈ 0.85W. At 2A and 1.8V output, conduction losses alone exceed this-requiring careful layout, copper pour, or airflow to maintain TJ ≤ 150°C.

Is soft-start time adjustable, and what is the minimum CSS value?

Yes. Soft-start time tSS (ms) = (CSS in nF × 0.6V) / ISS, where ISS = 3μA for this variant. Minimum CSS is 1nF, yielding ~200ms tSS. Larger capacitors extend ramp time linearly-e.g., 4.7nF gives ~940ms-providing flexibility to match system reset timing requirements.