Monolithic Power Systems Inc. MP5921GV-P

Overview

MP5921GV-P 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 fault reporting logic. It delivers up to 50A continuous current at 25°C (60A with airflow), operates from 4V–16V input, and actively limits inrush during live insertion into backplane systems-enabling robust power delivery in server blade slots and modular networking equipment.

For engineers reviewing the MP5921GV-P datasheet, MP5921GV-P pinout, MP5921GV-P application, or MP5921GV-P equivalent, this page provides verified functional context, validated pin-level circuit roles, confirmed thermal and current-limiting behavior, and real-world parallel operation constraints-not generic hot-swap guidance.

Technical Context

The MP5921GV-P implements a gate-controlled high-side e-fuse with dual-stage current limiting: soft-start phase uses V_BE-clamped CLREF (≤635mV when V_OUT < 80%V_IN) for controlled ramp-up, while normal operation uses programmable CLREF (up to 1.6V) with 10µA/A CS gain for precise 50A/60A current regulation. Its integrated charge pump drives the MOSFET gate without external components.

It features active current balancing across paralleled units via synchronized soft-start and shared CLREF/CS feedback paths, supports standalone or controller-driven operation via ON/PD pin, and reports faults-including drain-source short detection, OTP (143°C), and SCP (<200ns response)-through open-drain GOK and D_OC outputs.

Key Specifications

Pinout & Package

MP5921GV-P is housed in an FCQFN-28 (4mm × 5mm) package with exposed thermal pad (pin 25 = GND). The layout supports high-current routing: VIN (pins 1–4, 18), OUT (pins 5–17), and thermal-aware placement of VTEMP/GOK/IMON for signal integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS23521RGET and LM5069MMX/NOPB, MP5921GV-P uniquely combines 50A capacity, 1mΩ R_DS(ON), integrated thermal/current telemetry, and hardware-synchronized parallel operation-making it the only choice for high-density, diagnostics-enabled hot-swap systems requiring >40A per slot.

Availability

MP5921GV-P is available at Aetrix Electronics and suitable for server blade hot-swap, modular networking switch power distribution, and industrial PLC I/O module designs requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for MP5921GV-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 power management ICs, with design centers in the US, China, and Taiwan.

The MP5921 product line targets intelligent power distribution in datacenter and telecom infrastructure, delivering integrated hot-swap solutions that replace discrete MOSFETs, controllers, and sensing elements with single-chip reliability.

FAQ

What is the maximum safe operating current for MP5921GV-P in still air?

The MP5921GV-P sustains 50A continuous current at 25°C ambient with no forced airflow, as validated by thermal testing on 4-layer 2oz copper PCBs. Derating begins above 25°C per θ_JA = 38°C/W; at 60°C ambient, max current drops to ~38A to maintain 125°C junction limit. Airflow extends headroom to 60A by reducing effective θ_JA.

How does the CLREF pin function during soft-start versus normal operation?

During soft-start, CLREF is internally clamped: ≤635mV when V_OUT < 80%V_IN (to limit inrush), rising to ≤1.6V once V_OUT ≥ 80%V_IN. In normal operation, the external CLREF voltage directly sets OCP threshold via I_CS = 10µA/A × I_LOAD, enabling precise current limiting independent of startup conditions.

Can MP5921GV-P be used without an external hot-swap controller?

Yes - MP5921GV-P supports standalone operation using the ON/PD pin. Driving ON/PD >1.4V initiates soft-start; pulling ON/PD to ~1.2V engages internal 500Ω pull-down for controlled V_OUT discharge. No external controller is needed for basic hot-swap, though controllers add sequencing and telemetry aggregation.

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

GOK asserts low and latches on over-temperature (143°C), short-circuit (>100A), over-current timeout (>180µs), or FET drain-source short detection. Recovery requires cycling VIN or toggling ON/PD - no automatic reset. This ensures faults are acknowledged before power restoration, meeting safety-critical system requirements.

How is current sharing achieved when multiple MP5921GV-P devices operate in parallel?

Parallel MP5921GV-P units share current via synchronized soft-start (identical SS capacitor values) and matched RCS/RIMON resistors. During startup, CLREF clamping and gate drive regulation align turn-on timing; in steady state, CS outputs feed identical comparator thresholds, forcing equal current division within ±5% tolerance per unit.

Does the VTEMP pin provide absolute temperature or relative delta measurement?

VTEMP delivers absolute junction temperature: 370mV at 25°C with 8.7mV/°C slope (0–140°C range). It is factory-trimmed and requires no calibration - enabling direct ADC conversion to °C with ±2°C accuracy across the full operating range, critical for thermal throttling decisions.

What is the purpose of the D_OC pin, and how does it differ from GOK?

D_OC is a fast, non-latching open-drain over-current flag asserting low when CS voltage exceeds 85% of CLREF - indicating imminent OCP activation. Unlike latched GOK, D_OC resets immediately when current falls below threshold, making it ideal for dynamic current limiting feedback to external controllers without interrupting operation.