Monolithic Power Systems Inc. MP5003EQ-LF-Z

Overview

MP5003EQ-LF-Z from Monolithic Power Systems is a 3.3V programmable current-limit load switch with integrated 44mΩ DMOS FET, adjustable 1A–3A current limit via external resistor, 1.1ms default output slew rate, and auto-restart thermal protection. It serves as an input-protected hot-swap controller in portable power rails, limiting inrush and short-circuit current while providing UVLO (2.35V typ), overvoltage clamping (4.03V typ), and bi-directional Enable/Fault signaling.

For engineers reviewing the MP5003EQ-LF-Z datasheet, MP5003EQ-LF-Z pinout, MP5003EQ-LF-Z application, or MP5003EQ-LF-Z equivalent, key selection criteria include its QFN10 (3×3mm) package with exposed thermal pad, 44mΩ R_DS(on) at +25°C, trip/hold current programmability, dv/dt-controlled soft-start, and fault-handling behavior under thermal, UVLO, and overcurrent conditions.

Technical Context

The MP5003EQ-LF-Z implements a sense-FET-based current-limit architecture where trip and hold thresholds are set by an external resistor between +ILIMIT and –ILIMIT pins, enabling precise 1.2A–3.0A trip current tuning. Its internal charge pump drives the gate of a low-R_DS(on) power FET, eliminating external gate drive requirements.

It integrates multiple protection layers: Under-Voltage Lockout (UVLO) with 2.35V turn-on threshold and 300mV hysteresis, output voltage clamping at 4.03V (typ) for overvoltage events, and thermal shutdown at 175°C with automatic recovery. The Enable/Fault pin operates bidirectionally-pulling low on fault, releasing to 25µA weak pull-up when healthy-and supports wired-OR fault bus configurations.

Key Specifications

Pinout & Package

MP5003EQ-LF-Z uses a thermally enhanced QFN10 (3mm × 3mm) package with exposed thermal pad (VIN connected), optimized for PCB heat dissipation. Pin 11 is the exposed VIN pad; pins 1–5 are paralleled VOUT terminals for low-inductance, high-current output routing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS2557DRCT and NCP45520MUTBG, MP5003EQ-LF-Z uniquely combines programmable current limit, dv/dt-adjustable soft-start, UVLO, and auto-restart thermal protection in a single QFN10 package-making it optimal for dynamic hot-swap and multi-rail fault-isolation systems.

Availability

MP5003EQ-LF-Z is available at Aetrix Electronics and suitable for hot-swap card insertion, USB OTG power switching, and smartphone battery charging path protection requiring stable component supply across industrial temperature ranges (–20°C to +85°C).

Supply support for MP5003EQ-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 core expertise in DC/DC conversion, LED drivers, and intelligent power switches.

The MP5003 belongs to MPS's programmable load switch product line, designed specifically for robust hot-swap, inrush control, and fault-isolated power distribution in space-constrained portable and embedded systems.

FAQ

What is the maximum continuous output current supported by MP5003EQ-LF-Z?

The MP5003EQ-LF-Z supports up to 3A continuous output current when configured with RLIMIT = 13Ω (trip current = 4A, hold current = 3.2A). However, sustained 3A operation requires adequate PCB copper area and thermal vias on the exposed VIN pad to maintain junction temperature below 125°C under worst-case ambient conditions.

How does the dv/dt pin affect startup behavior, and what happens if left unconnected?

When the dv/dt pin is left floating, the internal circuit applies a fixed 1.1ms (typ) output voltage ramp from 10% to 90%. This default soft-start prevents inrush current spikes and contact arcing during hot-plug. Adding an external capacitor linearly increases ramp time-e.g., 1nF extends it to 23.5ms-allowing fine-grained control over system power-up sequencing.

Can MP5003EQ-LF-Z be used with input voltages below 3.3V?

Yes-the MP5003EQ-LF-Z operates from 2.5V to 6V input. At VIN = 2.5V, UVLO ensures the device remains disabled until voltage rises above 2.35V (typ), and R_DS(on) increases to ~95mΩ (at +80°C), resulting in ~140mW loss at 1.5A. System designers must verify that downstream loads tolerate the reduced headroom and higher conduction loss at low VIN.

What is the function of the Enable/Fault pin during normal operation versus fault conditions?

In normal operation, the Enable/Fault pin is released and pulled high by an internal 25µA current source-no external pull-up needed. During UVLO, overcurrent, or thermal fault, it is actively driven low. After thermal shutdown, it remains low until die temperature falls below hysteresis (~155°C), then returns high automatically-enabling seamless recovery without host intervention.

Is the exposed thermal pad electrically isolated, and how should it be connected?

No-the exposed pad (Pin 11) is internally connected to VIN and must be soldered to a dedicated VIN copper pour with ≥4 thermal vias to inner ground/power planes. It is not isolated; connecting it to GND or any other net will cause catastrophic failure. Per MPS layout guidelines, this pad is essential for both electrical functionality and thermal performance (θ_JA = 50°C/W).

How does current limit accuracy vary with temperature and supply voltage?

Current limit accuracy is specified over –20°C to +85°C and VIN = 3.3V. At VIN = 2.5V, trip current decreases ~5% due to reduced charge pump efficiency; at +80°C, hold current drops ~15% versus +25°C (per Note 4, "Guaranteed by design"). For production-critical applications, RLIMIT tolerance and temperature drift must be factored-e.g., 1% resistor yields ±1.2% trip current variation at room temperature.