Monolithic Power Systems Inc. MP2151GTF-12-P

Overview

MP2151GTF-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 PG indicator - deployed in battery-powered portable instruments and low-voltage I/O power rails.

For engineers reviewing the MP2151GTF-12-P datasheet, MP2151GTF-12-P pinout, MP2151GTF-12-P application, or MP2151GTF-12-P equivalent, key selection criteria include its ultra-small SOT563 package, 1.1MHz switching frequency, 0.5ms soft-start, 100% duty cycle capability, and PG open-drain output with 150μs delay - critical for power sequencing in space-constrained, low-I_Q systems.

Technical Context

The MP2151GTF-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 high-side P-channel and low-side N-channel MOSFETs (80mΩ/50mΩ) support up to 1A continuous output with 100% duty-cycle operation for near-dropout conditions.

It integrates a dedicated power-good (PG) open-drain output that asserts when V_OUT reaches 90% of 1.2V and deasserts at 85%, with 150μs delay and <0.4V sink voltage at 1mA. Output discharge is enabled automatically during shutdown via an internal 200Ω resistor, eliminating need for external discharge circuitry.

Key Specifications

Pinout & Package

SOT563 (1.6mm × 1.6mm × 0.55mm) package with wettable flanks, RoHS-compliant, lead-free, halogen-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS62231DRYR and ADP2301ARMZ-1.2-R7, MP2151GTF-12-P uniquely combines 1A capability, SOT563 size, integrated PG, and automatic output discharge - reducing component count and improving reliability in space- and power-constrained portable systems.

Availability

MP2151GTF-12-P is available at Aetrix Electronics and suitable for portable medical sensors, wearable health monitors, industrial handheld scanners, and low-voltage I/O interface cards requiring stable component supply with guaranteed long-term sourcing.

Supply support for MP2151GTF-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, founded in 1997 and headquartered in Kirkland, Washington.

The MP2151 product line targets ultra-compact, low-quiescent-current DC/DC conversion for battery-powered and space-constrained applications - emphasizing integration, efficiency, and ease of use in portable, medical, and industrial edge devices.

FAQ

What is the maximum allowable input voltage for MP2151GTF-12-P?

The absolute maximum input voltage is 6.5V, but the recommended operating range is strictly 2.5V to 5.5V. Exceeding 5.5V risks triggering the 6.1V absolute VIN OVP, which halts switching until VIN drops below 5.7V. This protection is independent of the 115% V_OUT OVP and safeguards against transient overvoltage events on the input rail.

Does MP2151GTF-12-P require external feedback resistors?

No. MP2151GTF-12-P is a fixed-output variant with internal resistor divider set to 1.2V; the FB pin is not connected and must be left floating or tied to GND per datasheet guidance. Only adjustable versions (e.g., MP2151GTF) use external R1/R2 networks - using resistors on this part would disrupt regulation and void accuracy guarantees.

How does the output discharge function operate during shutdown?

When EN is pulled low, the MP2151GTF-12-P automatically activates an internal 200Ω NMOS discharge path between OUT and GND. This discharges the output capacitor within ~1–3ms depending on C_OUT value, preventing residual voltage from back-powering downstream logic or causing latch-up in interconnected circuits - no external components required.

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

The PG pin is an open-drain output indicating valid 1.2V regulation (90–115% window). It requires an external pull-up resistor (100–500kΩ) to VIN or another clean supply. When asserted, PG rises to the pull-up voltage; when deasserted, it sinks to <0.4V at 1mA. PG delay is 150μs, making it suitable for synchronizing FPGA configuration or MCU wake-up sequences.

Can MP2151GTF-12-P operate at 100% duty cycle, and under what conditions?

Yes - the MP2151GTF-12-P supports 100% duty cycle when VIN ≤ V_OUT + dropout (typically ≤1.25V). This enables continued regulation during deep battery discharge (e.g., Li-ion at 3.0V input dropping to 2.8V), maintaining system operation where other buck converters would drop out. No external components or mode changes are needed.

Is thermal performance validated for the SOT563 package in real PCB layouts?

Yes - the datasheet specifies θ_JA = 80°C/W on a 2-layer 63mm×63mm EV2151-TF-00A evaluation board. At 1A load and 5V input, case temperature rise is ≤8°C above ambient, confirming suitability for thermally constrained handheld enclosures without heatsinking or airflow.

What protection features activate during a short-circuit event?

During short-circuit, the MP2151GTF-12-P enters hiccup-mode: it disables switching, discharges the soft-start capacitor, waits ~10ms, then attempts soft restart. If fault persists, it repeats. Simultaneously, Vo OVP engages - turning on the low-side FET to sink current until V_OUT falls below 105% - limiting peak stress on internal MOSFETs and inductor.