Monolithic Power Systems Inc. MP5921GV-Z

Overview

MP5921GV-Z from Monolithic Power Systems is a monolithic hot-swap Intelli-Fuse IC integrating a 1mΩ R_DS(ON) high-side MOSFET, current mirror, on-die temperature sensor, and 3.0V LDO. It delivers up to 50A continuous current (60A with airflow), limits inrush during live insertion into backplanes, and provides fault reporting via GOK and D_OC outputs - deployed in server power distribution units and modular networking equipment.

For engineers reviewing the MP5921GV-Z datasheet, MP5921GV-Z pinout, MP5921GV-Z application, or MP5921GV-Z equivalent, key selection considerations include its 4–16V input range, integrated current/temperature sensing eliminating external sense resistors, soft-start programmability via SS capacitor, parallel operation capability for >50A loads, and fault latching behavior under over-current, short-circuit, or over-temperature conditions.

Technical Context

The MP5921GV-Z implements a closed-loop gate control architecture that regulates the integrated MOSFET's V_GS using CLREF voltage and CS feedback to enforce precise current limiting during both soft-start and steady-state operation. Its current-limit reference clamps dynamically: to ~635mV (V_BE) when V_OUT < 80%V_IN, and to 1.6V once V_OUT ≥ 80%V_IN, enabling controlled ramp-up and full conduction.

It features dual fault detection paths: fast 200ns short-circuit protection triggered at ~100A, and slower over-current response (~14µs) with 180µs timeout before GOK latching. The GOK output asserts low and latches on over-current, short-circuit, over-temperature (143°C), or FET drain-source short detection - all confirmed by internal diagnostics and reported to host controllers.

Key Specifications

Pinout & Package

MP5921GV-Z is housed in an FCQFN-28 (4mm × 5mm) package with exposed thermal pad, optimized for high-current PCB layouts and thermal management in dense server modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar hot-swap e-fuse applications.

Compared with TPS2491RGER and LTC4215IMS#PBF, MP5921GV-Z delivers lower conduction loss (1mΩ vs. ≥3.5mΩ), eliminates four external components (shunt, LDO, thermal sensor, soft-start cap), and provides analog telemetry (IMON, VTEMP, CS) essential for predictive maintenance in datacenter infrastructure.

Availability

MP5921GV-Z is available at Aetrix Electronics and suitable for server blade power distribution, modular networking switch line cards, disk drive backplanes, and industrial PLC I/O modules requiring stable component supply across multi-year production cycles.

Supply support for MP5921GV-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-efficiency power management ICs for computing, cloud, automotive, and industrial markets.

The MP5921 product line delivers integrated hot-swap Intelli-Fuse solutions targeting high-density, high-reliability power distribution in datacenter and telecom infrastructure - emphasizing reduced BOM count, thermal intelligence, and fault resilience.

FAQ

What is the maximum continuous current rating for MP5921GV-Z under natural convection?

The MP5921GV-Z delivers 50A continuous current at 25°C ambient with no forced airflow, validated per its absolute maximum ratings and thermal resistance (θ_JA = 38°C/W). Derating is required above 25°C; at 60°C ambient, max continuous current drops to approximately 42A to maintain T_J ≤ 125°C.

How does the MP5921GV-Z implement short-circuit protection differently from over-current protection?

Short-circuit protection activates within 200ns when load current exceeds ~100A, using a dedicated fast-turn-off path independent of the CLREF loop. Over-current protection responds in ~14µs when CS exceeds 85% of CLREF, with a 180µs timeout before GOK latching - distinguishing transient surges from sustained faults.

Can MP5921GV-Z operate without an external hot-swap controller?

Yes - MP5921GV-Z supports standalone operation using ON/PD pin control: applying >1.4V enables the FET, while pulling ON/PD to ~1V after 2.1ms initiates VOUT pull-down. No external controller is needed for basic hot-swap functionality, though controllers add sequencing and telemetry integration.

What is the function of the VTEMP pin, and how is it calibrated?

VTEMP provides an 8.7 mV/°C analog output referenced to GND, spanning 0–140°C (370 mV to 1.6V). It is factory-trimmed and requires no external calibration; system firmware maps voltage to temperature using the specified gain and offset - enabling real-time die thermal monitoring without external sensors.

How does the CLREF clamp mechanism prevent thermal runaway during start-up?

During soft-start, CLREF is clamped to ~635mV (V_BE) when V_OUT < 80%V_IN, limiting inrush current to a safe level. Once V_OUT rises above 80%V_IN, the clamp releases to 1.6V, allowing full current. This two-stage clamping prevents excessive power dissipation before thermal equilibrium is reached.

Is parallel operation of multiple MP5921GV-Z devices supported, and how is current sharing ensured?

Yes - MP5921GV-Z supports active current sharing in parallel configurations. During soft-start and steady-state, internal circuitry equalizes gate drive and monitors CS outputs across devices, ensuring balanced load distribution within ±5% tolerance even with mismatched layout parasitics.

What failure modes trigger the GOK output, and is it auto-recoverable?

GOK asserts low and latches on over-current (after 180µs timeout), short-circuit (200ns), over-temperature (143°C), or FET drain-source short detection. Recovery requires cycling VIN or toggling ON/PD - no automatic reset - ensuring persistent fault indication until root cause is addressed.