Monolithic Power Systems Inc. MP62551DGT-LF-Z

Overview

MP62551DGT-LF-Z from Monolithic Power Systems is a precision programmable current-limited power distribution switch with active-high enable, 88mΩ N-channel MOSFET, ±10% current-limit accuracy (60mA–1.7A), 2.5V–5.5V input range, and integrated thermal shutdown. It delivers up to 1.5A continuous output current and is used in USB power distribution, PC card hot-swap, and portable GPS devices.

For engineers reviewing the MP62551DGT-LF-Z datasheet, MP62551DGT-LF-Z pinout, MP62551DGT-LF-Z application, or MP62551DGT-LF-Z equivalent, key selection criteria include programmable current limit via external resistor, fast 2μs over-current response, reverse-voltage protection at 135mV, FLAG open-drain fault reporting, and TQFN-6 (2×2mm) package compatibility with thermal pad grounding.

Technical Context

The MP62551DGT-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 resistor tolerance.

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

TQFN-6 (2×2mm) package with exposed thermal pad (internally connected to GND); requires external connection of pad to PCB ground plane for thermal management and electrical reference.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS2557DRCT and AP22653AW5-7, MP62551DGT-LF-Z uniquely combines ±10% programmable current limit, 135mV reverse-voltage protection, and dual thermal thresholds - making it optimal for space-constrained portable systems requiring precise, self-contained load management.

Availability

MP62551DGT-LF-Z is available at Aetrix Electronics and suitable for USB power distribution, PC card hot-swap, and portable GPS device designs requiring stable component supply, RoHS-compliant packaging, and long-term lifecycle support.

Supply support for MP62551DGT-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 global manufacturing and quality certifications including ISO 9001 and IATF 16949.

The MP62550/MP62551 product line targets compact, high-reliability power distribution in portable and embedded systems-designed specifically for applications demanding precision current limiting, robust fault handling, and minimal external components.

FAQ

What is the function of the ILIM pin on MP62551DGT-LF-Z?

The ILIM pin sets the current-limit threshold by connecting an external resistor to GND. With 12.4kΩ–210kΩ resistors, it programs 60mA–1.7A (typ) limits with ±10% accuracy. Shorting ILIM to IN configures the minimum 60mA limit. The pin interfaces directly with an internal precision current-sense amplifier, not a DAC or digital interface.

Does MP62551DGT-LF-Z provide reverse-voltage protection, and how does it behave?

Yes-it features dedicated reverse-voltage protection that disables the internal N-MOSFET when VOUT exceeds VIN by 135mV (typ). This occurs within 5ms and prevents backfeed current from damaging upstream circuitry. The protection activates regardless of EN state and recovers automatically once the condition is removed, without requiring power cycle or reset.

How does the FLAG pin indicate different fault conditions?

FLAG is an open-drain output that pulls low on over-current or over-temperature events. Over-current faults are deglitched with a 7.5ms timeout to reject transients; over-temperature asserts immediately without deglitching. FLAG remains unchanged during input UVLO transitions, ensuring fault reporting integrity across input brownouts.

What is the purpose of the exposed thermal pad on the TQFN-6 package?

The exposed pad is internally connected to GND and serves dual roles: thermal dissipation (θ_JA = 80°C/W on 4-layer PCB) and low-impedance ground reference. It must be soldered to a PCB copper pour tied to system GND; omitting this connection degrades thermal performance and may cause premature thermal shutdown under 1A load.

Can MP62551DGT-LF-Z be used in automotive applications?

No-its specified operating ambient temperature is -40°C to +85°C, and it lacks AEC-Q100 qualification, automotive-grade reliability testing, or extended junction temperature rating. It is intended for commercial portable and computing applications, not under-hood or safety-critical vehicle systems.

Is there a difference between MP62550 and MP62551 regarding enable logic?

Yes-MP62550 has active-low EN (logic low enables), while MP62551 (including MP62551DGT-LF-Z) has active-high EN (logic high enables). Both share identical current-limiting, protection, and package specifications; only the enable polarity differs, allowing direct substitution where control logic matches.

What is the minimum recommended input capacitance for stable operation?

A minimum 10μF ceramic or tantalum capacitor is required between IN and GND to suppress supply transients and improve immunity to short-circuit noise. Additional 0.01μF–0.1μF ceramic bypassing near the IN pin further enhances high-frequency noise rejection and ensures reliable UVLO and enable functionality.