Monolithic Power Systems Inc. MP2151GQFU-25-P

Overview

MP2151GQFU-25-P from Monolithic Power Systems is a fixed-output 2.5V, 1A synchronous step-down DC/DC converter with 25μA quiescent current, constant-on-time (COT) control, and integrated 80mΩ/50mΩ MOSFETs. It operates from 2.5V–5.5V input, delivers ±1.5% output accuracy over temperature, and includes output discharge, OVP, SCP, and thermal shutdown-designed for space-constrained battery-powered devices requiring ultra-low IQ.

For engineers reviewing the MP2151GQFU-25-P datasheet, MP2151GQFU-25-P pinout, MP2151GQFU-25-P application, or MP2151GQFU-25-P equivalent, key selection considerations include its UTQFN (1.2mm×1.6mm) package, 1.1MHz switching frequency, EN-controlled power sequencing, 0.5ms soft-start, and fixed 2.5V output with PG indicator-critical for portable instrumentation and low-power I/O rail generation.

Technical Context

The MP2151GQFU-25-P uses constant-on-time (COT) control with input voltage feed-forward to maintain stable 1.1MHz switching across 2.5V–5.5V input and 2.5V output, enabling fast transient response without external compensation. Its internal P-channel high-side (80mΩ) and N-channel low-side (50mΩ) MOSFETs support up to 1A continuous output in discontinuous or continuous conduction mode.

Sleep-mode operation reduces quiescent current to 25μA at light load by clamping the error amplifier and regulating valley FB voltage; AAM modulation with zero-current detection ensures DCM operation under light loads. The fixed 2.5V version integrates a power-good (PG) open-drain output with 90%/85% rising/falling thresholds and 150μs delay.

Key Specifications

Pinout & Package

MP2151GQFU-25-P is housed in an ultra-small UTQFN package (1.2mm × 1.6mm, 0.5mm height, 0.4mm pitch) with wettable flanks for automated optical inspection. Thermal resistance θJA = 65°C/W on a 2-layer PCB.

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, MP2151GQFU-25-P uniquely combines 1A capability, 25μA IQ, UTQFN footprint, output discharge, and PG in a single device-making it optimal for space- and battery-limited 2.5V rail generation where full protection and sequencing are mandatory.

Availability

MP2151GQFU-25-P is available at Aetrix Electronics and suitable for wireless networking cards, portable medical instruments, low-power industrial sensors, and multi-function printer logic rails requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP2151GQFU-25-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, including DC/DC converters, LED drivers, and motor drivers, with design centers in the US, China, and Taiwan.

The MP2151 product line targets ultra-compact, battery-powered applications demanding minimal quiescent current, fast transient response, and integrated protection-optimized for portable, wearable, and IoT edge devices.

FAQ

What is the recommended input capacitor for MP2151GQFU-25-P?

A 10μF X5R/X7R ceramic capacitor placed within 1mm of the VIN and GND pins is required to suppress high-frequency switching noise and prevent input voltage droop during load transients. A 1μF ceramic in parallel improves high-frequency decoupling. Total effective capacitance must remain ≥10μF at DC bias.

Does MP2151GQFU-25-P require external feedback resistors?

No. MP2151GQFU-25-P is a fixed-output variant with internal resistor divider set to 2.5V; the FB pin is unused and must be left unconnected. External resistors are only required for adjustable versions like MP2151GQFU.

How does the output discharge function operate?

When EN is pulled low or floats, the internal 200Ω NMOS discharge path between OUT and GND activates automatically, discharging the output capacitor in approximately 1ms (dependent on COUT value). This meets safety requirements for rapid rail collapse during shutdown sequences.

What is the purpose of the PG pin, and how should it be used?

The PG pin is an open-drain output that pulls low when the 2.5V output deviates outside the 90%–115% window (2.25V–2.875V). It requires a 100–500kΩ pull-up resistor to VIN or VOUT. PG asserts high after 150μs once regulation is confirmed, enabling synchronized system startup.

Can MP2151GQFU-25-P operate with a 1.5V input?

No. The absolute minimum input voltage is 2.5V, enforced by an under-voltage lockout (UVLO) threshold of 2.45V (rising). Operation below 2.5V is prohibited; attempting to power from 1.5V will prevent startup and may cause undefined behavior.

Is thermal derating required for continuous 1A operation?

Yes. At TA = +85°C, maximum continuous output current drops to ~0.85A due to thermal limits. Derating follows θJA = 65°C/W; for 1A full-load operation, ensure PCB copper area and airflow keep junction temperature ≤125°C per datasheet specifications.

What inductor value is recommended for MP2151GQFU-25-P?

A 1.0μH shielded power inductor with ≤50mΩ DCR is recommended. Typical values range from 1.0μH to 2.2μH; lower inductance improves transient response but increases ripple current. Avoid unshielded inductors to prevent EMI coupling into adjacent analog circuits.