Monolithic Power Systems Inc. MP6541GQKT-Z

Overview

MP6541GQKT-Z from Monolithic Power Systems is a three-phase BLDC motor power stage IC integrating six N-channel MOSFETs (15 mΩ HS/LS), three half-bridge drivers, six pre-drivers, dual gate-drive supplies, and three bidirectional current-sense amplifiers. It delivers 8A continuous output current at 40V max input, supports 100% duty cycle via internal charge pump, and targets compact fan, drone, and power tool motor drives.

For engineers reviewing the MP6541GQKT-Z datasheet, MP6541GQKT-Z pinout, MP6541GQKT-Z application, or MP6541GQKT-Z equivalent, key selection considerations include its PWM/ENBL logic interface (vs. HS/LS inputs on MP6541A), integrated OCP with 10–19A HS threshold, thermal shutdown at 150°C, and TQFN-26 package thermal resistance (θJA = 21.4°C/W).

Technical Context

The MP6541GQKT-Z implements a fully integrated three-phase gate driver architecture with independent enable (ENA/ENB/ENC) and PWM (PWMA/PWMB/PWMC) inputs per phase, enabling synchronous rectification and precise commutation control for BLDC motors. Its internal charge pump generates VCP = VIN + 5V to sustain high-side drive at 100% duty cycle, while trickle charging maintains gate voltage under sustained conduction.

Current sensing uses matched internal amplifiers with phase-specific gain ratios (e.g., 1/11600 typ for Phase A), delivering ±25 µA offset and rail-to-rail 0–5V output swing into ≥1.8 kΩ pull-up loads. Protection includes UVLO (4.4 V threshold), OVP (48 V), and fast OCP (0.4 µs deglitch) with automatic 2 ms retry after fault clearance.

Key Specifications

Pinout & Package

TQFN-26 (6mm × 6mm) package with exposed thermal pad; 0.4 mm pitch, JEDEC MO-220 compliant; requires thermal vias and copper pour for 5.84W max power dissipation at 25°C ambient.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar three-phase BLDC power stage applications.

Compared with MP6541GQKT-Z, MP6541AGQKT-Z provides identical power performance with different control interface flexibility, while STSPIN32F0A trades off higher integration and intelligence for lower voltage rating and reduced current capacity-making MP6541GQKT-Z optimal for high-power, externally controlled BLDC systems.

Availability

MP6541GQKT-Z is available at Aetrix Electronics and suitable for computer cooling fan control, drone propulsion systems, cordless power tools, and industrial pump controllers requiring stable component supply across production lifecycles.

Supply support for MP6541GQKT-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 power management ICs, with over two decades of innovation in DC/DC converters, motor drivers, and LED controllers.

The MP6541 product line delivers highly integrated three-phase power stages for BLDC and PMSM motors, designed to replace discrete MOSFET/gate-driver solutions in space-constrained, thermally demanding applications like drones and power tools.

FAQ

What is the maximum allowable continuous output current for MP6541GQKT-Z?

The MP6541GQKT-Z supports 8A continuous output current per phase under typical thermal conditions using a 4-layer PCB with adequate copper pour and thermal vias. Peak current reaches 12A for ≤1 second, limited by junction temperature (150°C) and θJA = 21.4°C/W. Actual current depends on ambient temperature, airflow, and heatsinking.

How does the internal charge pump enable 100% duty cycle operation?

The charge pump generates VCP = VIN + 5V to drive high-side MOSFET gates above the source potential, eliminating reliance on bootstrap capacitors that fail at 100% duty cycle. A trickle-charge circuit sustains VCP during sustained conduction, verified by 2 MHz switching frequency and 1 µF VIN–VCP capacitor requirement.

Can MP6541GQKT-Z be used with sensorless BLDC control?

Yes-its bidirectional current-sense outputs (SOA/SOB/SOC) and fast OCP response (0.4 µs deglitch) support back-EMF zero-crossing detection and current-based commutation algorithms. However, external MCU or DSP resources are required for real-time processing, as the device lacks on-chip motor control logic.

What is the recommended external capacitor for the VG pin?

A 4.7 µF to 10 µF X7R ceramic capacitor rated for ≥10V must be placed between VG and GND, located adjacent to the pin on the same PCB layer. This stabilizes the internal 5.5V LDO supplying low-side gate drivers and prevents shoot-through during fast switching transitions.

Does MP6541GQKT-Z support regenerative braking?

Yes-automatic synchronous rectification allows reverse current flow through low-side MOSFETs during inductive energy recovery. When Sx falls below GND, the LS-FET turns on to conduct recirculating current, minimizing body-diode losses and enabling efficient braking without external diodes.

What is the function of the LSS pin, and how should it be connected?

LSS is the common source node for all three low-side MOSFETs and serves as the reference for current-sense amplifiers. It must be connected directly to system GND with a low-inductance, wide copper trace-never routed through shared ground planes-to ensure accurate current measurement and prevent false OCP triggering.

How does the nFAULT pin behave during over-current events?

nFAULT is an open-drain output pulled low during OCP, thermal shutdown, UVLO, or OVP faults. It remains asserted for 2 ms after OCP detection (OCP retry time), then automatically clears if the fault condition is resolved. An external pull-up resistor (typically 10 kΩ to 3.3V) is mandatory for proper MCU interrupt signaling.