Monolithic Power Systems Inc. MP2148GQD-25-Z

Overview

MP2148GQD-25-Z from Monolithic Power Systems is a fixed-output 2.5V, 1A synchronous step-down DC/DC converter in a 1.0mm × 1.5mm QFN-6 package. It operates from 2.3V–5.5V input, delivers ultra-low 11μA quiescent current, features constant-on-time control for fast transient response, and integrates 120mΩ/80mΩ internal PMOS/NMOS power switches - optimized for battery-powered wearable devices requiring stable low-voltage I/O rail generation.

For engineers reviewing the MP2148GQD-25-Z datasheet, MP2148GQD-25-Z pinout, MP2148GQD-25-Z application, or MP2148GQD-25-Z equivalent, key selection criteria include its fixed 2.5V output accuracy (±1% over temperature), 2.2MHz switching frequency enabling compact 1μH inductor use, integrated output discharge, hiccup-mode short-circuit protection, and PG open-drain indicator with 70μs delay and 85–90% trip thresholds.

Technical Context

The MP2148GQD-25-Z employs constant-on-time (COT) control with input-voltage feedforward to maintain stable 2.2MHz switching across 2.3V–5.5V input and full load range. Its internal architecture integrates high-side PMOS (120mΩ) and low-side NMOS (80mΩ) switches, eliminating external MOSFETs and gate drivers.

It implements sleep-mode operation at light load via error-amplifier clamping and AAM (Advanced Asynchronous Modulation) with ZCD detection, reducing quiescent current to 11μA while maintaining regulation. The fixed 2.5V output version includes a dedicated open-drain Power Good (PG) pin with 85–90% voltage window detection and 400mV sink capability.

Key Specifications

Pinout & Package

MP2148GQD-25-Z is housed in an ultra-small QFN-6 package (1.0mm × 1.5mm, 0.5mm pitch) with exposed thermal pad for enhanced heat dissipation. The package supports reflow soldering per JEDEC MO-220 and requires minimal PCB area.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output buck converter applications.

Compared with TPS62231DRYR and ADP2302AUJZ-2.5-R7, MP2148GQD-25-Z delivers superior battery runtime due to 11μA IQ, smaller 1.0×1.5mm QFN footprint, and integrated PG/discharge - making it optimal for miniaturized, long-life portable systems demanding full-feature integration in minimal area.

Availability

MP2148GQD-25-Z is available at Aetrix Electronics and suitable for wearable health monitors, Bluetooth LE sensor nodes, industrial handheld scanners, and smart home motion detectors requiring stable component supply and long-term production continuity.

Supply support for MP2148GQD-25-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 analog and power ICs, with a focus on energy-efficient DC/DC conversion, motor drivers, and LED lighting solutions.

The MP2148 product line targets ultra-compact, battery-sensitive applications - delivering high-efficiency step-down regulation in sub-2mm² packages with industry-leading quiescent current and integrated protection features.

FAQ

What is the minimum input voltage required for MP2148GQD-25-Z to regulate 2.5V output?

The MP2148GQD-25-Z requires a minimum input voltage of 2.3V to maintain regulation at 2.5V output. Below this threshold, the under-voltage lockout (UVLO) circuit disables the device. The 2.25V rising UVLO threshold with 150mV hysteresis ensures clean startup and shutdown behavior across temperature.

Does MP2148GQD-25-Z require external feedback resistors to set the output voltage?

No. MP2148GQD-25-Z is a fixed-output variant with internal resistor divider network configured for 2.5V. Unlike the adjustable MP2148GQD version, it does not use the FB pin for voltage setting - instead, Pin 1 functions exclusively as an open-drain Power Good (PG) indicator.

How does the Power Good (PG) pin behave during startup and fault conditions?

The PG pin remains low until VOUT reaches 85% of 2.5V (2.125V), then transitions high after a 70μs delay. If VOUT drops below 85% or exceeds 90% of nominal, the internal MOSFET pulls PG low. Its 400mV max sink voltage at 1mA ensures compatibility with standard logic-level inputs.

Can MP2148GQD-25-Z operate with 100% duty cycle, and what is its significance?

Yes, MP2148GQD-25-Z supports 100% duty cycle operation, allowing VOUT to approach VIN (e.g., 2.5V output from 2.7V input). This maximizes efficiency in near-dropout conditions and eliminates discontinuous conduction mode instability common in light-load scenarios.

What thermal derating applies to the 1A output current rating?

The 1A rating is specified at TA = +25°C with proper PCB copper pour on the exposed thermal pad. At +85°C ambient, continuous output current derates to ~750mA due to θJA = 220°C/W and thermal shutdown at 160°C junction temperature - requiring ≥100mm² 2oz copper pad for full-rated operation.

Is an external soft-start capacitor required for MP2148GQD-25-Z?

No. MP2148GQD-25-Z integrates a fixed 0.5ms soft-start timer that controls output voltage ramp rate internally. This eliminates external components while ensuring controlled startup without overshoot, even with large output capacitance.

What is the recommended inductor value and key selection criteria?

A 1.0μH shielded power inductor (e.g., Wurth 74438322010) is recommended. Key criteria include DC resistance <15mΩ, saturation current >1.5A, and magnetic shielding to minimize EMI. Inductor ripple current should be ~30% of max load (300mA) to balance efficiency and transient response.