Monolithic Power Systems Inc. MP2249DN-LF-P

Overview

MP2249DN-LF-P from Monolithic Power Systems is a 1MHz, 3A synchronous step-down DC/DC converter optimized for single-cell Li+-battery-powered portable electronics. It operates from 2.5V to 6V input, delivers adjustable output from 0.6V to VIN, integrates main PFET and synchronous NFET switches, and supports 100% duty cycle for low-dropout operation in space-constrained applications such as smartphones and digital cameras.

For engineers reviewing the MP2249DN-LF-P datasheet, MP2249DN-LF-P pinout, MP2249DN-LF-P application, or MP2249DN-LF-P equivalent, key selection criteria include its 1MHz fixed-frequency current-mode control, internal soft-start and output discharge functions, power-good indicator, thermal and short-circuit protection, and compatibility with compact 3mm×3mm TQFN10 or SOIC8E packages.

Technical Context

The MP2249DN-LF-P implements constant-frequency (1MHz), slope-compensated current-mode PWM control with cycle-by-cycle overcurrent limiting and 100% duty-cycle capability for dropout operation. Its integrated high-side PFET (92mΩ typ) and low-side NFET (72mΩ typ) eliminate external Schottky diodes and enable up to 90% peak efficiency at 3A load.

It features an internal 0.6V reference with ±2% FB voltage tolerance over temperature, programmable output via resistor divider, open-drain PG signal with 85–90% VOUT window detection, and EN pin with 1.8V turn-on/0.4V turn-off thresholds and 450kΩ internal pull-down.

Key Specifications

Pinout & Package

MP2249DN-LF-P is supplied in an SOIC8E package with exposed thermal pad (pin 2–3), offering enhanced thermal performance over standard SOIC-8. The exposed pad must be soldered to a PCB ground plane for optimal junction-to-ambient heat dissipation (θ_JA = 50°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS62231DRVR and RT7295BGJ6F, MP2249DN-LF-P uniquely combines 1MHz operation, integrated output discharge, PG indicator, and 100% duty cycle in a dual-package SOIC8E/TQFN10 option-making it optimal for battery-powered systems requiring robust sequencing, low dropout, and minimal external components.

Availability

MP2249DN-LF-P is available at Aetrix Electronics and suitable for smartphone power management, portable medical instrumentation, digital camera subsystems, and wireless audio devices requiring stable component supply across production lifecycles.

Supply support for MP2249DN-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 design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MP2249 belongs to MPS's low-voltage DC/DC converter product line, engineered specifically for Li+-battery-powered portable electronics where efficiency, size, and seamless integration of protection and sequencing features are critical.

FAQ

What is the maximum output current capability of MP2249DN-LF-P under real-world thermal conditions?

The MP2249DN-LF-P is rated for 3A continuous output current at TA = +25°C with proper PCB thermal design (SOIC8E with exposed pad soldered to ≥1in² copper). At +85°C ambient, derating applies: maximum sustainable current drops to ~2.2A due to thermal limits (θ_JA = 50°C/W, TJ(MAX) = 125°C). Full 3A operation requires adequate airflow or thermal vias under the exposed pad.

Does MP2249DN-LF-P support pre-biased output startup?

No-MP2249DN-LF-P does not support true pre-bias startup. When enabled into a pre-biased output, the internal discharge MOSFET briefly sinks current, potentially causing bus contention. For pre-bias applications, external isolation (e.g., ideal diode or OR-ing FET) is required upstream of the converter output.

How is the output voltage set, and what tolerance does the feedback reference have?

Output voltage is set using an external resistor divider from VOUT to FB and FB to GND. The internal reference is 0.6V with ±2% tolerance over –40°C to +85°C (0.588V to 0.612V). This yields ±2% output accuracy assuming perfect resistors; typical total error including resistor tolerance and layout parasitics is ±3.5%.

Can MP2249DN-LF-P operate with only ceramic capacitors on input and output?

Yes-MP2249DN-LF-P is fully compatible with all-ceramic designs. Recommended input capacitance is ≥47µF X5R/X7R; output capacitance is ≥22µF per rail. Ceramic caps meet low-ESR requirements for stable 1MHz operation and eliminate electrolytic aging concerns in portable equipment.

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

On output short, MP2249DN-LF-P enters cycle-by-cycle current limiting (4.5A peak), then latches off when FB falls below 67% of 0.6V (UV threshold). Recovery requires cycling EN or removing/reapplying input power-no automatic retry. This prevents thermal runaway and enables deterministic system-level fault handling.

Is the EN pin compatible with standard GPIOs from microcontrollers?

Yes-the EN pin has TTL-compatible thresholds (turn-on >1.8V, turn-off <0.4V) and includes a 450kΩ internal pull-down resistor. It draws <1µA when held high, making it directly drivable by 1.8V, 3.3V, or 5V GPIOs without level-shifting or external resistors.

What is the minimum inductor value recommended, and why?

The minimum recommended inductor is 1.5µH (e.g., Würth 744310200). Smaller values increase peak inductor current and ripple, risking saturation and reduced efficiency. At 1MHz and 3A load, 1.5–2.2µH balances size, ripple (~900mA), and core loss-ensuring stable current-mode control and <20mΩ DCR for minimal conduction loss.