Monolithic Power Systems Inc. MP62551DGT-LF-P

Overview

MP62551DGT-LF-P 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, and 60mA–1.7A (typ) adjustable limit set by external resistor. It operates from 2.5V to 5.5V input and delivers up to 1.5A continuous output current in portable USB power distribution and smart phone load switching applications.

For engineers reviewing the MP62551DGT-LF-P datasheet, MP62551DGT-LF-P pinout, MP62551DGT-LF-P application, or MP62551DGT-LF-P equivalent, key selection criteria include programmable current-limit range, fast 2μs over-current response, thermal shutdown threshold (155°C), reverse-voltage protection trip point (135mV), and FLAG open-drain fault reporting behavior under over-temperature and over-current conditions.

Technical Context

The MP62551DGT-LF-P integrates an internal charge pump enabling gate drive above VIN down to 2.5V, supporting full N-MOSFET conduction across its entire 2.5V–5.5V supply range. Its current-sense amplifier enables precise constant-current regulation during overload, with deglitched 7.5ms fault assertion for over-current and immediate (non-deglitched) reporting for over-temperature.

Reverse-voltage protection activates when VOUT exceeds VIN by ≥135mV (typ), triggering MOSFET turn-off within 5ms via controlled gate discharge. The device features automatic recovery after fault removal, UVLO with 2.45V rising-edge threshold and 130mV hysteresis, and bidirectional deglitch timing on FLAG for robust noise immunity.

Key Specifications

Pinout & Package

MP62551DGT-LF-P uses a 6-pin TQFN package (2mm × 2mm, 0.7mm–0.9mm height) with exposed thermal pad connected internally to GND. Pin 1 is marked with chamfered corner; the thermal pad must be soldered to PCB ground plane for thermal performance and electrical stability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS22965DSGR and RT9711CGJ5, MP62551DGT-LF-P uniquely combines ±10% programmable current limiting, 135mV reverse-voltage protection, and deglitched FLAG reporting-enabling single-chip USB-compliant power switching without auxiliary components.

Availability

MP62551DGT-LF-P is available at Aetrix Electronics and suitable for USB power distribution, smartphone load switching, notebook PC subsystem power, and portable GPS device power management requiring stable component supply, RoHS-compliant packaging, and long-term lifecycle support.

Supply support for MP62551DGT-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 core expertise in DC/DC conversion, LED drivers, and intelligent power switches.

The MP6255x series belongs to MPS's precision power distribution switch product line, designed specifically for portable and USB-powered systems requiring accurate current limiting, robust fault protection, and minimal board space.

FAQ

What is the minimum recommended ILIM resistor value for MP62551DGT-LF-P?

The minimum recommended ILIM resistor is 12.4kΩ (1% tolerance), which sets the current limit to approximately 1.7A (typ). Using a lower resistance risks exceeding the device's maximum current capability and may degrade accuracy due to amplifier offset effects outside the validated range.

Does MP62551DGT-LF-P provide reverse-current blocking when IN = 0V and OUT = 5.5V?

Yes. With IN at 0V and OUT at 5.5V, the internal N-MOSFET remains fully off regardless of EN state, resulting in reverse leakage current of only 0.01–1μA. This behavior is guaranteed by the reverse-voltage comparator and gate discharge circuit, not dependent on enable logic.

How does the FLAG pin behave during input UVLO transitions?

The FLAG pin remains unchanged during UVLO activation or release-it asserts low only for over-current or over-temperature faults. When VIN drops below 2.25V (UVLO threshold), the device disables but FLAG retains its prior state, avoiding false fault signaling during power-rail brownouts.

Can MP62551DGT-LF-P be used with a 1.8V logic enable signal?

No. The EN pin requires VIH ≥1.1V to guarantee turn-on; a 1.8V signal meets this requirement. However, the absolute minimum VIH is 1.1V, and the device is not specified for 1.8V logic families-use level-shifting if interfacing with true 1.8V GPIOs to ensure margin.

What is the thermal resistance θ_JA for MP62551DGT-LF-P in its TQFN package?

The junction-to-ambient thermal resistance (θ_JA) is 80°C/W, measured on a standard 4-layer JEDEC PCB per JESD51-7. This value assumes proper soldering of the exposed thermal pad to a ≥1cm² copper pour connected to GND for optimal heat dissipation.

Is soft-start time adjustable externally?

No. Soft-start timing (0.5–1.5ms V_OUT rise time) is internally fixed and not user-adjustable. It is determined by internal charge-pump dynamics and gate-drive slew rate, ensuring consistent inrush control without external components.

Does MP62551DGT-LF-P support auto-retry functionality out-of-the-box?

No. Auto-retry requires external RC circuitry connecting FLAG to EN (as shown in Figure 6 of the datasheet). The IC itself provides only fault detection and automatic recovery upon fault removal-not cyclic retry behavior without added components.