Monolithic Power Systems Inc. MP62550DJ-LF-Z

Overview

MP62550DJ-LF-Z from Monolithic Power Systems is a precision 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 88mΩ R_DS(on) in TSOT23-6 package. It operates from 2.5V–5.5V input, features reverse-voltage protection, thermal shutdown at 155°C, and open-drain FLAG output for fault reporting - used in USB power distribution and portable GPS device power rail control.

For engineers reviewing the MP62550DJ-LF-Z datasheet, MP62550DJ-LF-Z pinout, MP62550DJ-LF-Z application, or MP62550DJ-LF-Z equivalent, key selection considerations include programmable current limit via ILIM resistor, fast 2μs over-current response, soft-start timing (0.5–1.5ms V_OUT rise), deglitched FLAG reporting, and TSOT23-6 thermal performance (θ_JA = 220°C/W).

Technical Context

The MP62550DJ-LF-Z integrates an N-channel power MOSFET with internal charge pump enabling gate drive above input voltage - allowing full enhancement down to 2.5V IN. Its current-limit circuit uses a precision amplifier sensing voltage across an external R_ILIM, enabling accurate setting of 60mA–1.7A (typ) with ±10% 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 open-drain FLAG pin asserts low after 3.5–10ms deglitch delay for over-current faults but responds immediately to over-temperature events - and remains unchanged during UVLO transitions.

Key Specifications

Pinout & Package

MP62550DJ-LF-Z uses the TSOT23-6 package (2.9mm × 1.6mm × 1.1mm), featuring exposed thermal pad internally connected to GND for PCB heat sinking. Pin 1 is bottom-left when reading top marking left-to-right (5Y).

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 NCP45520MUTBG, MP62550DJ-LF-Z uniquely balances programmability (60mA–1.7A), compact TSOT23-6 footprint, reverse-voltage blocking, and integrated deglitched FLAG - making it optimal for space-constrained portable systems requiring flexible, robust rail protection.

Availability

MP62550DJ-LF-Z is available at Aetrix Electronics and suitable for USB power distribution, portable GPS device power management, and notebook PC subsystem protection requiring stable component supply, RoHS-compliant packaging, and long-term lifecycle support.

Supply support for MP62550DJ-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 mixed-signal ICs for power management, motion control, and interface applications.

The MP62550/MP62551 product line delivers precision programmable current-limiting switches for portable and embedded systems - designed to replace discrete FET + sense + protection circuits with integrated, thermally optimized solutions.

FAQ

What is the minimum recommended R_ILIM value for MP62550DJ-LF-Z?

The minimum recommended R_ILIM is 12.4kΩ (1% tolerance), corresponding to a typical current limit of 1.7A. Using lower resistance risks exceeding the maximum specified current limit and may reduce accuracy due to amplifier saturation effects documented in the datasheet's Figure 5 and Table 1.

Does MP62550DJ-LF-Z provide reverse-current blocking when input is 0V?

Yes - with VIN = 0V and VOUT = 5.5V, reverse leakage is specified at 0.01–1μA regardless of EN state. The internal reverse-voltage comparator disables the MOSFET when VOUT exceeds VIN by 135mV, preventing significant reverse conduction even during battery-backup scenarios.

How does the auto-retry function work with MP62550DJ-LF-Z?

Auto-retry is implemented externally using an RC network between FLAG and EN. When FLAG pulls low during a fault, EN is driven low, disabling the switch. As FLAG goes high-impedance, the RC network recharges EN. Once EN crosses its 1.1V threshold, the device re-enables - cycling until the fault clears, as shown in Figure 6 of the datasheet.

What is the thermal resistance (θ_JA) for MP62550DJ-LF-Z in TSOT23-6 package?

The junction-to-ambient thermal resistance is 220°C/W (measured per JESD51-7 on a 4-layer PCB). This value assumes proper thermal pad soldering to ≥1cm² copper area; insufficient copper or missing thermal vias will degrade actual performance and reduce safe continuous current.

Can MP62550DJ-LF-Z operate with 2.5V input and still achieve full 1.5A output?

Yes - the internal charge pump enables full gate drive for the N-channel MOSFET down to 2.5V input, maintaining R_DS(on) ≤135mΩ and supporting 1.5A continuous current. However, V_OUT rise time increases to 0.75ms at 2.5V (vs. 0.5ms at 5.5V), as confirmed in Electrical Characteristics Table 4.

Is the FLAG pin actively driven high or open-drain?

The FLAG pin is strictly open-drain. It pulls low (≤180mV at 1mA) during over-current or over-temperature faults and releases to high-impedance otherwise. An external pull-up resistor (typically 10kΩ to VIN or logic rail) is required to establish a valid high-level signal for microcontroller interrupt detection.

What happens to output voltage during thermal shutdown?

During thermal shutdown, the internal MOSFET turns off completely, causing V_OUT to fall to near 0V (limited only by load leakage paths). Recovery occurs automatically once die temperature drops ~10°C below the 155°C shutdown threshold - no reset or EN toggle is required.