Monolithic Power Systems Inc. MP2249DQT-LF-P

Overview

MP2249DQT-LF-P from Monolithic Power Systems is a 1MHz, 3A synchronous step-down DC/DC converter optimized for single-cell Li-ion battery-powered portable electronics. It integrates high-side and low-side MOSFETs, supports 2.5V–6V input, delivers adjustable output from 0.6V to VIN, and operates at 100% duty cycle for ultra-low dropout in applications like smartphone core supplies.

For engineers reviewing the MP2249DQT-LF-P datasheet, MP2249DQT-LF-P pinout, MP2249DQT-LF-P application, or MP2249DQT-LF-P equivalent, key selection criteria include its 1MHz fixed-frequency current-mode control, integrated output discharge, power-good indicator, thermal and short-circuit protection, and TQFN10 (3mm×3mm) package with exposed thermal pad.

Technical Context

The MP2249DQT-LF-P implements constant-frequency current-mode PWM control with slope compensation to ensure stability at >50% duty cycles and provide cycle-by-cycle overcurrent limiting. Its internal 0.6V reference and feedback architecture enable precise output regulation across temperature and load.

It features an integrated 92mΩ P-channel main switch and 72mΩ N-channel synchronous rectifier, enabling up to 90% efficiency at 3A. The device includes internal soft-start (1ms ramp), output discharge MOSFET (~100Ω on-resistance), and open-drain PG output with 85–90% VFB window detection.

Key Specifications

Pinout & Package

MP2249DQT-LF-P uses a 3mm × 3mm TQFN-10 package with exposed thermal pad (Pin 2/3) for enhanced thermal performance. Pin numbering follows JEDEC MO-229 VEED-5 standard.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous step-down converter applications.

Compared with TPS62231DRYT and RT7295BGJ6F, MP2249DQT-LF-P uniquely combines adjustable output, integrated discharge, PG indicator, and 100% duty cycle in a 3mm×3mm TQFN-making it optimal for Li-ion portable designs requiring full feature integration and minimal external components.

Availability

MP2249DQT-LF-P is available at Aetrix Electronics and suitable for smartphone core supplies, portable instrument power rails, digital camera sensor bias, and wearable MCU power management requiring stable component supply, RoHS-compliant packaging, and long-term production continuity.

Supply support for MP2249DQT-LF-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 analog and power ICs, with expertise in DC/DC conversion, LED drivers, and motor control solutions.

The MP2249 belongs to MPS's low-voltage synchronous buck converter product line, designed specifically for space-constrained, battery-powered portable electronics demanding high efficiency, small footprint, and robust protection features.

FAQ

What is the maximum continuous output current of MP2249DQT-LF-P at 85°C ambient?

The MP2249DQT-LF-P delivers 3A continuously at TA = +85°C when mounted on a 4-layer PCB with the recommended land pattern and thermal pad soldered to a ≥1cm² copper pour. Derating begins above this temperature due to θJA = 50°C/W and TJ(MAX) = 125°C.

Does MP2249DQT-LF-P support pre-biased output startup?

No - MP2249DQT-LF-P does not support true pre-bias startup. During enable, its internal discharge MOSFET actively sinks current from the output capacitor. If the output is pre-biased, the external supply must source more current than the ~10mA discharge capability to avoid conflict.

How is output voltage accuracy affected by temperature and load?

Output voltage accuracy is maintained by the 0.600V ±12mV (±2%) reference over −40°C to +85°C. Load regulation error remains within ±1% across 0–3A due to low R_DS(on) of internal FETs and current-mode control loop stability.

Can MP2249DQT-LF-P operate with ceramic output capacitors only?

Yes - MP2249DQT-LF-P is fully compatible with X5R/X7R ceramic output capacitors. Recommended values are 22µF ×2 (47µF total) with ESR <5mΩ. The internal compensation is optimized for ceramic-based loops with bandwidth ≤100kHz.

What is the purpose of the exposed thermal pad (Pins 2/3) and how should it be connected?

The exposed thermal pad (Pins 2/3) is electrically GND and thermally critical. It must be soldered to a solid PCB ground plane using ≥4 thermal vias (0.3mm diameter) to an inner ground layer. This reduces θJA by ~15°C/W and prevents thermal shutdown under full 3A load.

Is the PG pin actively driven or open-drain, and what voltage levels trigger its state change?

The PG pin is open-drain with internal 10kΩ pull-up option. It pulls low when output falls below 85% VFB (0.51V) or rises above 90% VFB (0.54V), or during shutdown. It goes high-Z (allowing external pull-up) only after output stabilizes within this window for >1ms.

What happens during short-circuit events, and how does recovery work?

On short-circuit, MP2249DQT-LF-P enters cycle-by-cycle current limit (4.5A peak), then latches off when FB drops below 67% VFB (0.4V). Recovery requires cycling EN or input power - no automatic retry - preventing thermal runaway during sustained faults.