Monolithic Power Systems Inc. MP2151GQFU-12-P

Overview

MP2151GQFU-12-P from Monolithic Power Systems is a fixed-output 1.2V, 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% output accuracy over temperature, and includes output discharge, OVP, SCP, and thermal shutdown-designed for space-constrained battery-powered systems like wireless sensors and portable instrumentation.

For engineers reviewing the MP2151GQFU-12-P datasheet, MP2151GQFU-12-P pinout, MP2151GQFU-12-P application, or MP2151GQFU-12-P equivalent, key selection considerations include its ultra-small UTQFN (1.2mm×1.6mm) package, 1.1MHz switching frequency, EN-controlled power sequencing, PG indicator functionality, and low-I_Q operation in light-load AAM mode.

Technical Context

The MP2151GQFU-12-P implements constant-on-time (COT) control with input voltage feed-forward to maintain stable 1.1MHz switching across 2.5V–5.5V input and 1.2V output, enabling fast transient response without external compensation. Its internal P-channel high-side (80mΩ) and N-channel low-side (50mΩ) MOSFETs eliminate external switch requirements.

It integrates output discharge via an internal 200Ω NMOS path when disabled, supports power sequencing via EN with 1.2V logic-high threshold, and provides a dedicated open-drain PG signal (with 150μs delay and ±5% window) only in fixed-output variants like this one-enabling reliable system power-good monitoring.

Key Specifications

Pinout & Package

MP2151GQFU-12-P uses a 6-pin UTQFN package (1.2mm × 1.6mm, 0.4mm pitch, 0.5mm height) with wettable flanks for automated optical inspection. Pin 1 is marked by a laser-etched dot; top marking is "GD" followed by lot code.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS6286512RQYR and ADP5302AUJZ-1.2-R7, MP2151GQFU-12-P uniquely balances ultra-low I_Q, integrated PG and discharge, robust 1A capability in minimal UTQFN size, and proven COT stability-making it optimal for cost-sensitive, space-constrained, and battery-life–driven embedded systems.

Availability

MP2151GQFU-12-P is available at Aetrix Electronics and suitable for wireless sensor nodes, portable medical instruments, industrial IoT edge controllers, and low-power networking cards requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP2151GQFU-12-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 expertise in DC/DC conversion, motor drivers, and LED lighting solutions.

The MP2151 product line targets ultra-compact, low-I_Q buck converters for battery-powered and space-constrained applications-emphasizing integration, efficiency at light loads, and simplified design through COT architecture and minimal external components.

FAQ

What is the purpose of the PG pin on MP2151GQFU-12-P?

The PG (Power Good) pin is an open-drain output that signals when the regulated 1.2V output is within ±5% of target (1.14V–1.26V). It requires an external 100–500kΩ pull-up resistor to VIN or VOUT and asserts high after a 150μs delay once regulation is achieved-enabling firmware or system PMIC to validate rail integrity before enabling downstream logic.

Can MP2151GQFU-12-P operate with input voltage below 2.5V?

No. The MP2151GQFU-12-P has a guaranteed operating input range of 2.5V to 5.5V, with UVLO rising threshold at 2.45V (typ.) and hysteresis of 200mV. Operation below 2.5V is outside specification and may result in unstable regulation, dropout, or undefined behavior-including failure to start or erratic PG assertion.

Does MP2151GQFU-12-P require external feedback resistors?

No. As a fixed-output variant, MP2151GQFU-12-P has internal feedback network set to 1.2V; the FB pin is not connected externally and must be left floating. External resistors are only required for adjustable versions (e.g., MP2151GQFU) to program V_OUT via R1/R2 divider.

How does the output discharge function work during shutdown?

When EN is pulled low or floats, the MP2151GQFU-12-P activates an internal 200Ω NMOS discharge path between OUT and GND. This safely bleeds stored charge from the output capacitor within ~1–2ms (depending on C_OUT value), preventing back-powering of upstream circuits or false logic states in powered-down subsystems.

Is thermal performance validated for 1A continuous load in UTQFN package?

Yes. Per MPS EV2151-QFU-00A evaluation board data, the UTQFN package achieves θ_JA = 65°C/W on a 2-layer 63mm×63mm PCB. At 1A, 1.2V output, and 5V input, typical power dissipation is ~350mW, resulting in ~23°C junction rise above ambient-well within the 125°C max operating junction temperature limit.

What protection features are active during short-circuit conditions?

Under short-circuit, MP2151GQFU-12-P triggers hiccup-mode protection: it disables switching, discharges the soft-start capacitor, waits ~10ms, then attempts soft restart. If fault persists, cycle repeats. Concurrently, output OVP monitors FB voltage and forces low-side conduction to clamp V_OUT if it exceeds 115% of 1.2V (1.38V).

Can EN be driven by a microcontroller GPIO without level-shifting?

Yes. The EN pin has a 1.2V logic-high threshold and 0.4V logic-low threshold, with 1.2μA input current at 2V. Standard 3.3V or 1.8V GPIO outputs meet these levels directly; no level shifter is needed. Internal 1MΩ pull-down ensures safe disable when GPIO is high-impedance or unconfigured.