Monolithic Power Systems Inc. MP62550DGT-LF-Z

Overview

MP62550DGT-LF-Z from Monolithic Power Systems is a precision single-channel programmable current-limited power distribution switch with active-low enable, delivering up to 1.5A continuous output current, ±10% current-limit accuracy over 60mA–1.7A (typ), and integrated 88mΩ N-channel MOSFET in a 2×2mm TQFN-6 package. It operates from 2.5V to 5.5V input and is used for USB power distribution and PC Card hot-swap protection in portable electronics.

For engineers reviewing the MP62550DGT-LF-Z datasheet, MP62550DGT-LF-Z pinout, MP62550DGT-LF-Z application, or MP62550DGT-LF-Z equivalent, key selection criteria include adjustable current limit via ILIM resistor, fast 2μs over-current response, reverse-voltage protection at 135mV, thermal shutdown at 155°C, and FLAG open-drain fault reporting with deglitch timing.

Technical Context

The MP62550DGT-LF-Z integrates an internal charge pump enabling gate drive above VIN down to 2.5V, ensuring full enhancement of its N-channel MOSFET across the entire supply range. Its current-limit circuit uses a precision amplifier with offset-compensated feedback to achieve ±10% accuracy over temperature and RILIM variation.

Thermal protection employs dual independent sensors: one triggers at 135°C during current-limit operation, the other at 155°C unconditionally, both with ~10°C hysteresis. The FLAG pin provides deglitched (7.5ms) over-current reporting but immediate (non-deglitched) over-temperature indication, and remains static during UVLO transitions.

Key Specifications

Pinout & Package

MP62550DGT-LF-Z is housed in a thermally enhanced 6-pin TQFN package (2mm × 2mm, 0.70–0.90mm height) with exposed GND pad for PCB heat sinking. Pin 1 is marked by chamfered corner and index area per JEDEC MO-229 VCCC.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar programmable current-limited power distribution switch applications.

Compared with TPS2557DRBR and NCP45561MUTBG, MP62550DGT-LF-Z uniquely combines resistor-programmable current limit, integrated reverse-voltage blocking, and internal soft-start in a 2×2mm footprint - reducing total solution size and component count for portable and space-sensitive designs.

Availability

MP62550DGT-LF-Z is available at Aetrix Electronics and suitable for USB power distribution, PC Card hot-swap, smartphone peripheral management, and set-top box peripheral rail isolation requiring stable component supply and long-term lifecycle support.

Supply support for MP62550DGT-LF-Z 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 core expertise in DC/DC conversion, LED drivers, and power distribution solutions.

The MP62550/MP62551 product line was designed specifically for precision, programmable current limiting in portable and embedded systems where space, thermal margin, and fault resilience are critical - targeting USB, hot-swap, and multi-rail power management applications.

FAQ

What is the minimum recommended R_ILIM value for MP62550DGT-LF-Z?

The minimum recommended R_ILIM is 12.4kΩ, which sets the current limit near 1.7A (typ). Using lower resistance risks exceeding the device's maximum current rating and may degrade accuracy due to amplifier saturation. For 60mA limit, connect ILIM directly to IN - not via resistor - as specified in the datasheet.

Does MP62550DGT-LF-Z require an external capacitor on the FLAG pin?

No external capacitor is required on the FLAG pin. Its deglitch timing (3.5–10ms for over-current) is fully internal and factory-trimmed. Adding external capacitance would distort fault reporting timing and is not supported. FLAG is open-drain and must be pulled up externally (e.g., 10kΩ to 3.3V/5V).

How does reverse-voltage protection behave when IN = 0V and OUT = 5.5V?

When IN = 0V and OUT = 5.5V, the internal N-MOSFET remains fully off regardless of EN state, resulting in <1μA reverse leakage (typ). No reverse current flows - the protection is inherent to the MOSFET's body diode orientation and gate control, requiring no external components or power.

Can MP62550DGT-LF-Z be used with input voltages below 2.5V?

No. The absolute minimum operating input voltage is 2.5V, enforced by internal UVLO (2.25V threshold with hysteresis). Below this, the device remains disabled and the MOSFET stays off. Operation at 2.4V or lower is not characterized and may result in unpredictable current limiting or failure to enable.

What is the thermal resistance θ_JA for MP62550DGT-LF-Z in standard layout?

For the TQFN-6 (2×2mm) package on a 4-layer PCB per JESD51-7, θ_JA is 80°C/W. This value assumes proper thermal pad soldering to ≥1cm² copper pour. Without adequate copper, θ_JA degrades significantly - e.g., to >150°C/W on 2-layer boards - limiting max continuous current to ~0.8A.

Is the FLAG pin asserted during UVLO activation?

No. The FLAG pin remains unchanged during input UVLO transitions - it only asserts low for over-current or over-temperature faults. This allows system firmware to distinguish between input undervoltage (e.g., battery sag) and true hardware faults, enabling appropriate recovery actions without false alarms.

What happens if the ILIM resistor is omitted or left floating?

Leaving ILIM floating causes undefined current-limit behavior and may result in excessive output current or latch-up. The ILIM pin must be either connected to GND via a valid resistor (12.4kΩ–210kΩ) or tied directly to IN for 60mA mode. Floating violates the ABSOLUTE MAXIMUM RATINGS and voids parametric guarantees.