Monolithic Power Systems Inc. MP62551DJ-LF-Z

Overview

MP62551DJ-LF-Z from Monolithic Power Systems is a precision programmable current-limited power distribution switch with active-high 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 (135mV trip), thermal shutdown at 155°C, and fast 2μs over-current response-used for USB power rail control in portable electronics.

For engineers reviewing the MP62551DJ-LF-Z datasheet, MP62551DJ-LF-Z pinout, MP62551DJ-LF-Z application, or MP62551DJ-LF-Z equivalent, key selection criteria include programmable current limit via ILIM resistor, FLAG open-drain fault reporting, soft-start timing (0.5–1.5ms VOUT rise), and TSOT23-6 thermal performance (θJA = 220°C/W).

Technical Context

The MP62551DJ-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 2.5–5.5V supply range. Its current-sense amplifier enables precise constant-current regulation during overload, with deglitched fault reporting (3.5–10ms) on the open-drain FLAG pin for over-current and over-temperature events.

Thermal protection uses dual independent sensors: one triggers at 135°C during current-limit operation, the other at 155°C unconditionally, both with ~10°C hysteresis. Reverse-voltage protection activates when VOUT − VIN exceeds 135mV (typ), initiating MOSFET turn-off within 5ms to prevent sink current into the input rail.

Key Specifications

Pinout & Package

MP62551DJ-LF-Z is housed in a thermally enhanced TSOT23-6 package (1.0mm × 2.8mm × 1.2mm) with exposed pad connected internally to GND for PCB heat sinking. Pin 1 is lower-left when reading top marking left-to-right (AAN).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS22965DSGR and NIS5130MN3T2G, MP62551DJ-LF-Z uniquely combines programmable current limiting, reverse-voltage protection, and deglitched fault reporting in a 2.8mm × 1.0mm TSOT23-6 footprint-enabling robust, space-constrained USB and mobile peripheral power architectures.

Availability

MP62551DJ-LF-Z is available at Aetrix Electronics and suitable for USB power distribution, smartphone peripheral rail control, notebook PC subsystem power, and telecom line card hot-swap applications requiring stable component supply, RoHS-compliant packaging, and long-term lifecycle support.

Supply support for MP62551DJ-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 design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MP6255x series belongs to MPS's precision power distribution switch product line, engineered specifically for portable and space-constrained systems needing accurate, programmable current limiting, robust fault handling, and minimal board area consumption.

FAQ

What is the minimum recommended R_ILIM value for MP62551DJ-LF-Z?

The minimum recommended R_ILIM is 12.4kΩ (1% tolerance), which sets the current limit to approximately 1.7A (typ). Using lower resistance risks exceeding the device's safe operating area and may degrade current-limit accuracy due to internal amplifier offset effects documented in the datasheet's Figure 5 and Table 1.

Does MP62551DJ-LF-Z support automatic retry after thermal shutdown?

Yes - MP62551DJ-LF-Z automatically recovers once junction temperature drops ~10°C below the 155°C shutdown threshold. For controlled auto-retry with delay, connect an RC network between FLAG and EN to implement timed re-enabling, as shown in Figure 6 of the datasheet.

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

When IN = 0V and OUT = 5.5V, the internal N-channel MOSFET remains fully off regardless of EN state, resulting in ≤1μA reverse leakage current. This behavior is guaranteed by the device's architecture and verified in Electrical Characteristics table (I_REV = 0.01–1μA).

Can the FLAG pin drive an LED directly without a current-limiting resistor?

No - FLAG is an open-drain output rated for 1mA sink current at 180mV VOL. Driving an LED directly would exceed this rating and cause undefined logic levels. A series current-limiting resistor (e.g., 10kΩ for 0.5mA at 5V) is required for indicator use.

Is the TSOT23-6 package of MP62551DJ-LF-Z pin-compatible with MP62550DJ-LF-Z?

Yes - both share identical TSOT23-6 pinout and footprint. The only functional difference is EN polarity: MP62551DJ-LF-Z uses active-high enable, while MP62550DJ-LF-Z uses active-low. No layout change is needed when swapping between them.

What is the maximum allowable power dissipation for MP62551DJ-LF-Z at 85°C ambient?

At T_A = +85°C, maximum continuous power dissipation is 0.26W, calculated as P_D(MAX) = (T_J(MAX) − T_A) / θ_JA = (125°C − 85°C) / 220°C/W. Exceeding this causes thermal shutdown; derating is required for sustained 1.5A loads in high-ambient environments.

Does the ILIM pin require decoupling or filtering?

No - ILIM is a high-impedance current-sense input. Adding capacitance degrades current-limit accuracy and response time. The datasheet specifies direct connection to a precision 1% resistor to GND; no bypassing or filtering is recommended or tested.