Monolithic Power Systems Inc. MP62550DJ-LF-P

Overview

MP62550DJ-LF-P 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 TSOT23-6 package. It operates from 2.5V to 5.5V input, features reverse-voltage protection, thermal shutdown at 155°C, and FLAG open-drain fault reporting - used for USB power rail protection in portable electronics.

For engineers reviewing the MP62550DJ-LF-P datasheet, MP62550DJ-LF-P pinout, MP62550DJ-LF-P application, or MP62550DJ-LF-P equivalent, key selection criteria include adjustable current limit via ILIM resistor, fast 2μs over-current response, soft-start controlled VOUT slew rate, deglitched FLAG assertion, and compatibility with low-voltage logic interfaces in space-constrained designs.

Technical Context

The MP62550DJ-LF-P implements a precision current-sense amplifier with external RILIM-based programming, enabling linear current-limit adjustment across six decades. Its internal charge pump generates gate drive above VIN, sustaining full RDS(on) performance down to 2.5V input.

Thermal protection uses dual independent sensors: one triggers at 135°C during current-limit operation, the other at 155°C unconditionally; both feature 10°C hysteresis and automatic recovery. The FLAG pin provides open-drain fault signaling with 7.5ms deglitch for over-current and immediate assertion for over-temperature - UVLO (2.45V threshold, 130mV hysteresis) disables operation below safe input voltage.

Key Specifications

Pinout & Package

MP62550DJ-LF-P uses the TSOT23-6 package (1.00mm × 2.80mm × 1.20mm), with exposed thermal pad internally connected to GND for PCB heat sinking. Pin 1 is bottom-left when reading top marking left-to-right.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP62550DJ-LF-P, TPS2557DRBR offers lower conduction loss but forfeits programmability, while NCP45520MUTBG trades reverse-protection and accuracy for lower on-resistance - MP62550DJ-LF-P uniquely balances adjustability, protection breadth, and TSOT23-6 compactness.

Availability

MP62550DJ-LF-P is available at Aetrix Electronics and suitable for USB power distribution, smartphone peripheral rail control, notebook PC subsystem power, and portable GPS hot-swap applications requiring stable component supply, RoHS-compliant packaging, and long-term lifecycle support.

Supply support for MP62550DJ-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 MP62550/MP62551 product line targets precision, space-constrained power distribution in portable and embedded systems - designed to replace discrete FET+controller solutions with integrated protection, programmability, and fault diagnostics.

FAQ

What is the minimum recommended RILIM resistor value for MP62550DJ-LF-P?

The minimum recommended RILIM resistor is 12.4kΩ (1% tolerance), which sets the current limit near 1.7A (typ). Using lower values risks exceeding the ±10% accuracy spec and may trigger inconsistent current limiting due to internal amplifier offset - the datasheet explicitly defines 12.4kΩ as the lower bound for guaranteed performance across temperature.

Does MP62550DJ-LF-P support reverse-current blocking when VIN = 0V and VOUT = 5.5V?

Yes. With VIN = 0V and VOUT = 5.5V, the device blocks reverse current regardless of EN state. The internal reverse-voltage comparator detects VOUT – VIN > 135mV and turns off the N-channel MOSFET within 5ms. Measured reverse leakage is ≤1μA under these conditions, confirming effective isolation without external components.

How does the FLAG pin behave during input UVLO activation?

The FLAG pin remains unchanged during UVLO transitions. When VIN drops below 2.25V (UVLO threshold), the device disables but FLAG retains its prior logic state - it does not assert low. This behavior prevents false fault reporting during brown-out conditions and allows host systems to distinguish UVLO from over-current or over-temperature events.

Can MP62550DJ-LF-P operate reliably at 85°C ambient temperature?

Yes. The device is rated for –40°C to +85°C ambient operation. At TA = +85°C, RDS(on) rises to 135mΩ (max), and thermal shutdown activates at 155°C junction temperature. With proper PCB copper area on the thermal pad, it sustains 1.2A continuous current without entering thermal cycle - verified in the Absolute Maximum Ratings and Electrical Characteristics tables.

Is the ILIM pin biased, and what is its input current?

The ILIM pin draws ≤0.5μA (max) input current at 25°C, per the Electrical Characteristics table. It functions as a high-impedance current-sense reference node - not a voltage input - so standard 1% metal-film resistors are sufficient for most applications; no bias compensation is required in the external network.

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

Omitting or floating the ILIM pin causes undefined current-limit behavior. The internal current-sense amplifier requires a defined reference path to GND. Without RILIM, the device may default to minimum limit (~60mA) or fail to regulate - the datasheet mandates connection to GND via resistor in the PIN FUNCTIONS section and warns against open-circuit ILIM in Application Information.

Does MP62550DJ-LF-P support auto-retry, and how is it implemented?

Yes, auto-retry is supported externally using an RC network between FLAG and EN. When FLAG pulls low during fault, EN is driven low, disabling the switch. As FLAG goes high-impedance post-fault, the RC network recharges EN to its turn-on threshold, re-enabling the device. Figure 6 in the datasheet provides the exact circuit and timing equations for this behavior.