Monolithic Power Systems Inc. MP2151GTF-25-P

Overview

MP2151GTF-25-P from Monolithic Power Systems is a fixed-output 2.5V, 1A synchronous step-down DC/DC converter in SOT563 package, featuring 25μA quiescent current, 1.1MHz switching frequency, and integrated 80mΩ/50mΩ power MOSFETs. It delivers stable low-voltage power for battery-powered microcontrollers and RF modules with output discharge, OVP, and hiccup-mode short-circuit protection.

For engineers reviewing the MP2151GTF-25-P datasheet, MP2151GTF-25-P pinout, MP2151GTF-25-P application, or MP2151GTF-25-P equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, confirmed application use cases, and two rigorously cross-checked alternative parts with documented functional differences.

Technical Context

The MP2151GTF-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 range while enabling fast transient response. Its internal high-side P-channel and low-side N-channel MOSFETs (80mΩ/50mΩ) eliminate external switch requirements.

It integrates output discharge via an internal NMOS path (200Ω), power-good indication (open-drain PG with ±5% window), and dynamic over-voltage protection that actively sinks current when FB exceeds 115% VREF. Sleep mode reduces IQ to 25μA at light load without compromising regulation accuracy (±1% FB reference).

Key Specifications

Pinout & Package

SOT563 package (1.6mm × 1.6mm × 0.55mm), thermally enhanced with exposed pad (GND-connected), rated for 1.5W dissipation at TA = +25°C on 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, MP2151GTF-25-P uniquely delivers full 1A output with integrated PG and output discharge in the same ultra-small SOT563 package - making it the only drop-in solution for space-constrained, safety-critical 2.5V systems requiring robust fault handling.

Availability

MP2151GTF-25-P is available at Aetrix Electronics and suitable for wireless sensor nodes, portable medical devices, industrial I/O modules, and FPGA configuration supplies requiring stable component supply with guaranteed long-term availability.

Supply support for MP2151GTF-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-efficiency, high-reliability power management ICs for computing, automotive, industrial, and consumer markets.

The MP2151 product line targets ultra-low-power, space-constrained DC/DC conversion in battery-operated and portable electronics, emphasizing minimal external components, sub-100μA IQ, and integrated protection features.

FAQ

Does MP2151GTF-25-P require external feedback resistors?

No. The "-25" suffix denotes a factory-trimmed fixed 2.5V output version. Internal reference and feedback network eliminate external resistors, reducing BOM count and improving accuracy over temperature (±1.5% total output tolerance). This differs from the adjustable MP2151GTF variant which requires R1/R2.

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

The PG pin is an open-drain output indicating valid 2.5V regulation (within ±5%). It requires a 100–500kΩ pull-up resistor to VIN. When asserted high, it signals the system controller that the rail is stable and ready for initialization - commonly used to release MCU reset or enable downstream peripherals.

Can MP2151GTF-25-P operate from a 2.4V input?

No. The under-voltage lockout (UVLO) rising threshold is 2.45V (min 2.3V). At 2.4V input, the device remains disabled. Minimum functional input is 2.5V per datasheet operating conditions; operation below this risks erratic behavior or failure to start.

How does output discharge work, and when is it active?

When EN is pulled low, an internal 200Ω NMOS connects OUT to GND, discharging the output capacitor. This occurs automatically upon disable - no external circuitry needed. Discharge completes in <1ms for typical 22μF output capacitance, preventing back-powering of upstream circuits.

Is thermal derating required for continuous 1A operation at 70°C ambient?

Yes. With θJA = 80°C/W (SOT563 on 2-layer PCB), 1A load at 5V input yields ~0.5W dissipation, causing ~40°C junction rise. At 70°C ambient, TJ ≈ 110°C - within 125°C max rating but near thermal warning threshold. Use thermal vias and copper pour to reduce θJA or consider UTQFN variant for higher power headroom.

What protection features activate during a short circuit at the output?

At short circuit, the 1.8A peak current limit triggers hiccup mode: switching halts, soft-start capacitor discharges, then automatic restart occurs after ~10ms. If short persists, cycle repeats. Simultaneously, output OVP detects rapid VOUT collapse and activates low-side sinking to clamp residual voltage - preventing damage to the internal MOSFETs.

Does MP2151GTF-25-P support forced PWM or auto-frequency scaling?

No. It uses constant-on-time (COT) control with input voltage feed-forward, resulting in natural frequency variation (±10%) with VIN and VOUT. There is no external pin or register to force fixed-frequency operation - this is inherent to its architecture for optimized light-load efficiency and transient response.