Monolithic Power Systems Inc. MP2151GQFU-25-Z

Overview

MP2151GQFU-25-Z from Monolithic Power Systems is a fixed-output 2.5V, 1A synchronous step-down DC/DC converter in UTQFN (1.2mm × 1.6mm) package, featuring 25μA quiescent current, 1.1MHz switching frequency, and integrated 80mΩ/50mΩ MOSFETs. It delivers high efficiency across 2.5V–5.5V input range and supports output discharge and over-voltage protection - ideal for space-constrained battery-powered IoT sensors and wearable power rails.

For engineers reviewing the MP2151GQFU-25-Z datasheet, MP2151GQFU-25-Z pinout, MP2151GQFU-25-Z application, or MP2151GQFU-25-Z equivalent, key selection considerations include its fixed 2.5V output with ±0.5% regulation accuracy over temperature, EN-controlled sequencing, thermal shutdown at 160°C, and compatibility with low-ESR ceramic output capacitors in ultra-small footprint designs.

Technical Context

The MP2151GQFU-25-Z employs constant-on-time (COT) control with input voltage feed-forward to maintain stable 1.1MHz switching across input and load variations. Its internal power stage integrates complementary P-channel and N-channel MOSFETs with on-resistances of 80mΩ and 50mΩ respectively, enabling high-efficiency operation down to light-load conditions via AAM (Advanced Asynchronous Modulation) and sleep mode.

It implements cycle-by-cycle current limiting (1.8A typical), hiccup-mode short-circuit protection, and dynamic output over-voltage regulation triggered at 115% V_FB. The fixed 2.5V version includes a dedicated open-drain Power Good (PG) output with 150μs delay and ±5% window detection relative to nominal output.

Key Specifications

Pinout & Package

MP2151GQFU-25-Z uses a 6-pin UTQFN package (1.2mm × 1.6mm, 0.4mm pitch) with wettable flanks for automated optical inspection. Thermal pad is internally connected to GND for enhanced heat dissipation in high-density PCB layouts.

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-Z uniquely combines 1A capability, integrated output discharge, and PG signaling in a 1.2mm × 1.6mm UTQFN - making it the only option among the three suitable for battery-powered systems requiring robust sequencing and fault handling at full 1A load.

Availability

MP2151GQFU-25-Z is available at Aetrix Electronics and suitable for wireless sensor nodes, wearable health monitors, industrial handheld scanners, and smart home edge controllers requiring stable component supply across long-lifecycle consumer and industrial programs.

Supply support for MP2151GQFU-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 power management ICs, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MP2151 belongs to MPS's ultra-low-I_Q synchronous buck converter product line, engineered specifically for battery-operated portable and IoT devices where standby current, small size, and integrated protection are critical system-level requirements.

FAQ

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

A 10μF X5R/X7R ceramic capacitor with ≤100mΩ ESR, placed within 2mm of VIN and GND pins, is required to suppress high-frequency switching noise and prevent input voltage sag during load transients. A 1μF ceramic in parallel improves high-frequency decoupling.

Does MP2151GQFU-25-Z require an external feedback resistor network?

No. The "-25" suffix denotes a factory-trimmed fixed 2.5V output; the internal resistor divider sets V_FB = 600mV, so the FB pin must be left unconnected. External resistors are only needed for adjustable versions like MP2151GQFU.

How does the output discharge function operate during shutdown?

When EN is pulled low, the internal 200Ω NMOS discharge path between OUT and GND activates automatically, discharging the output capacitor within ~1ms (dependent on C_OUT value). This prevents back-powering of upstream circuitry or latch-up in mixed-voltage systems.

Can MP2151GQFU-25-Z drive a 1A load continuously at 5.5V input and 85°C ambient?

Yes - thermal testing shows ≤10°C case temperature rise at 1A/5.5V/85°C ambient on a 2-layer 63mm×63mm PCB (θ_JA = 65°C/W). Derating is not required unless board copper area is reduced below EV2151-QFU-00A reference layout.

Is the Power Good (PG) output compatible with 1.8V logic systems?

Yes - PG is open-drain and requires an external pull-up resistor (100–500kΩ) to any logic-compatible voltage (1.8V, 3.3V, or VIN). Its sink capability exceeds 1mA at 0.4V, ensuring clean low-level signaling into standard CMOS inputs.

What failure modes trigger hiccup-mode protection?

Hiccup mode activates during sustained over-current (e.g., shorted output), over-temperature (>160°C), or persistent output over-voltage (>115% for >12μs). The device disables switching, discharges soft-start capacitance, waits ~10ms, then attempts restart - repeating until fault clears.

Does MP2151GQFU-25-Z support forced PWM or discontinuous conduction mode (DCM)?

No - it operates exclusively in COT-controlled pseudo-DCM/AAM mode. At light loads, it enters sleep mode with reduced switching frequency and extended off-times; no external mode-select pin or command is provided.