Monolithic Power Systems Inc. MP5018GD-P

Overview

MP5018GD-P from Monolithic Power Systems is a 5V, 1A–5A adjustable current-limit power switch with reverse current blocking, 5.8V fast over-voltage clamp, integrated 45mΩ N-channel MOSFET pair, and bi-directional EN/FAULT pin for fault indication and enable control. It operates from 4.5V to 5.5V input, supports hot-swap insertion into live backplanes, and delivers precise inrush current limiting via programmable soft-start (10.4–15.6ms) and external ILIMIT resistor configuration.

For engineers reviewing the MP5018GD-P datasheet, MP5018GD-P pinout, MP5018GD-P application, or MP5018GD-P equivalent, this device is selected for high-reliability 5V rail protection in PCIe cards, SSD/HDD power sequencing, and industrial hot-swap systems where reverse current blocking, OVP response <40μs, and latch-off thermal shutdown are mandatory design requirements.

Technical Context

The MP5018GD-P integrates dual back-to-back N-channel MOSFETs controlled by a charge-pump–assisted gate driver, enabling bidirectional current monitoring and sub-10μs reverse-current fault detection. Its UVLO (4.0V typ.) and fast OVP comparator (5.8V clamp, 10–40μs response) operate independently of the main control loop to ensure robust transient immunity.

Current limiting is implemented via an internal sense amplifier with programmable threshold (0.5–5A via ILIMIT resistor), while soft-start is governed by a 6.5μA constant-current source charging an external capacitor at the SS pin. The EN/FAULT pin functions as a tri-state interface-pulling low disables the device, floating enables auto-start, and mid-level (~1.3V) indicates thermal or reverse-current faults.

Key Specifications

Pinout & Package

MP5018GD-P is housed in a thermally enhanced QFN-12 package (2mm × 3mm, 0.5mm pitch) with exposed thermal pad (Pin 12 + Pad) for PCB heat sinking. The package supports reflow soldering per JEDEC J-STD-020 and achieves θ_JA = 70°C/W on a 4-layer board.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TUSB544RGET and TPS25940ARVCR, MP5018GD-P uniquely combines DEVSLP-compatible SAS control, 5.8V precision OVP, and auto-recovering reverse-current blocking - making it the most integrated solution for SATA/PCIe storage hot-swap where footprint, thermal performance, and protocol-aware power sequencing are critical.

Availability

MP5018GD-P is available at Aetrix Electronics and suitable for PCIe add-in cards, HDD/SSD power sequencing, and industrial hot-swap backplanes requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for MP5018GD-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 design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MP5018GD-P belongs to MPS's eFuse and hot-swap controller product line, engineered specifically for reliable 5V rail protection in storage, computing, and networking equipment where compact size, fast fault response, and protocol-aware control (e.g., DEVSLP) are essential.

FAQ

What is the minimum input voltage required for MP5018GD-P to enable output?

The MP5018GD-P features an Under-Voltage Lockout (UVLO) with a rising threshold of 4.0V typical (3.8–4.2V range). Output remains disabled until V_IN exceeds this threshold; once enabled, the device continues operating down to 4.5V minimum for stable regulation. Below 3.8V, EN/FAULT is actively pulled low to signal undervoltage condition.

Can MP5018GD-P be used with input voltages above 5.5V?

No - MP5018GD-P is rated for continuous operation only between 4.5V and 5.5V. While its absolute maximum input rating is 16V for transient survival (e.g., hot-swap arcing), sustained operation above 5.5V violates recommended conditions and may cause premature degradation or thermal shutdown. For >5.5V systems, consider TPS25940ARVCR or similar wide-input eFuses.

How does the EN/FAULT pin indicate a reverse current fault?

During reverse current events exceeding −1.2A for >7μs, the EN/FAULT pin transitions from high to a mid-level voltage (~1.3V, specified 0.9–1.95V), distinct from its low state (UVLO/SAS-disable) and high state (normal operation). This level is detectable by standard CMOS inputs and enables direct connection to microcontroller ADCs or comparators without external level-shifting.

What is the thermal shutdown behavior, and how is recovery performed?

MP5018GD-P enters latch-off thermal shutdown at 175°C typical (130–200°C range), driving EN/FAULT to mid-level and disabling output. Recovery requires toggling EN or SAS, or cycling V_IN - automatic restart does not occur. This prevents repeated thermal cycling under persistent overload and mandates system-level intervention before resuming operation.

Is the SS pin compatible with ceramic capacitors, and what tolerance is recommended?

Yes - the SS pin uses a 6.5μA internal current source to charge external capacitors, and ceramic capacitors (X5R/X7R) are strongly recommended for stability and low ESR. A 10% tolerance capacitor is sufficient; for example, a 22nF ±10% part yields t_SS = 3.38ms ±10%, well within the 10.4–15.6ms spec when floating. Avoid electrolytic or tantalum types due to leakage and aging effects.

Does MP5018GD-P require an external current-sense resistor?

No - MP5018GD-P integrates a precision current-sense amplifier and MOSFET driver, eliminating the need for external shunt resistors. Current limit is set solely by the resistor from ILIMIT to GND (or left floating for 3A fixed limit), reducing BOM count, board area, and power loss associated with discrete sensing.

What is the maximum load capacitance supported with 13ms soft-start?

With SS pin floating (13ms soft-start), MP5018GD-P can safely charge up to ~2200μF of total output capacitance at 3A limit. Larger loads will extend rise time beyond 13ms due to current limiting - for example, 4700μF requires ~28ms to reach 5V. Always verify dV/dt against downstream IC requirements using the formula t_SS ≈ C_LOAD × ΔV / I_LIM.