Monolithic Power Systems Inc. MP6541GQKT-P

Overview

MP6541GQKT-P from Monolithic Power Systems is a three-phase brushless DC (BLDC) motor power stage IC integrating six N-channel MOSFETs, six pre-drivers, dual gate-drive power 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 features thermal shutdown, UVLO, OCP, and OVP protection. It is used in compact BLDC motor control systems for drones, power tools, and HVAC blowers.

For engineers reviewing the MP6541GQKT-P datasheet, MP6541GQKT-P pinout, MP6541GQKT-P application, or MP6541GQKT-P equivalent, key selection criteria include its 15mΩ HS/LS FET on-resistance, integrated synchronous rectification logic, 3-phase current sensing with ±25µA offset, TQFN-26 thermal performance (θJA = 21.4°C/W), and PWM/ENBL vs. HS/LS input mode distinction between MP6541 and MP6541A variants.

Technical Context

The MP6541GQKT-P implements a fully integrated three-phase half-bridge architecture with independent gate drive for each high-side and low-side MOSFET. Its internal charge pump generates VCP ≈ VIN + 5V to sustain high-side gate drive at 100% duty cycle, while a trickle-charge circuit maintains voltage under sustained conduction.

Current sensing uses matched internal amplifiers per phase with typical gain of 1/11,600 A/A and output swing from 0V to 5V referenced to VREF. Fault handling includes cycle-by-cycle over-current detection (IOCP(HS) = 10–19A, IOCP(LS) = 17.5–25A), 2ms auto-retry, and open-drain nFAULT signaling with thermal shutdown at 150°C and 25°C hysteresis.

Key Specifications

Pinout & Package

TQFN-26 (6mm × 6mm) package with exposed thermal pad (pin 18 GND connected internally to pad). Designed for high-power density and efficient heat transfer via PCB thermal vias and copper pour.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP6541AGQKT-P, the MP6541GQKT-P offers simpler PWM/EN logic for basic commutation but less timing flexibility; versus STSPIN32F0A, it delivers 5.7× higher current capability and integrated current sensing-critical for torque-controlled industrial motors.

Availability

MP6541GQKT-P is available at Aetrix Electronics and suitable for drone propulsion systems, cordless power tools, HVAC blower modules, and industrial pump drives requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for MP6541GQKT-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 over two decades of expertise in DC/DC converters, motor drivers, and battery management solutions.

The MP6541 product line targets high-efficiency, space-constrained BLDC and PMSM motor control applications, emphasizing integration of power switches, gate drivers, sensing, and protection in thermally optimized packages.

FAQ

What is the difference between MP6541GQKT-P and MP6541AGQKT-P?

The MP6541GQKT-P uses enable (ENA/ENB/ENC) and PWM (PWMA/PWMB/PWMC) inputs per phase, while the MP6541AGQKT-P replaces those with separate high-side (HSA/HSB/HSC) and low-side (LSA/LSB/LSC) control inputs. All other specifications-including R_DS(on), current rating, protection features, package, and pinout-are identical. The choice depends on control architecture: PWM/EN suits simple trapezoidal commutation; HS/LS enables precise dead-time control for FOC or custom timing.

Does MP6541GQKT-P support 100% duty cycle operation?

Yes. The device integrates an internal charge pump that generates VCP ≈ VIN + 5V to drive high-side MOSFET gates, supported by a trickle-charge circuit that maintains sufficient gate voltage during sustained conduction. This eliminates reliance on external bootstrap capacitors and enables true 100% duty cycle without loss of high-side drive strength.

How is current sensing implemented and what external components are required?

Each phase has a dedicated current-sense amplifier (SOA/SOB/SOC) delivering a current output proportional to load current (gain ≈ 1/11,600 A/A). To convert to voltage for ADC input, place a termination resistor (R_TERM) between SOx and VREF (typically 5V). For ratiometric ADCs, use two equal resistors from SOx to V_CC and GND. No external op-amps or gain-setting resistors are needed-the amplifiers are fully integrated and trimmed.

What thermal design practices are recommended for sustained 8A operation?

To sustain 8A continuous current, use a 4-layer PCB with ≥2oz copper on top/bottom layers, connect the exposed thermal pad (under package) to internal GND planes via ≥9 thermal vias (0.3mm diameter), and allocate ≥250mm² of copper pour around the IC. With this layout, θJA drops to ~21.4°C/W, allowing operation up to +125°C junction temperature at 25°C ambient.

Can MP6541GQKT-P drive PMSM motors using field-oriented control (FOC)?

Yes. Its three-channel, matched current-sense outputs (SOA/SOB/SOC) provide the analog feedback required for I_d/I_q estimation in FOC algorithms. Combined with independent PWM timing and synchronous rectification, it supports both sensored and sensorless FOC implementations-though external MCU or DSP is required for the control loop execution.

What protection features activate during a phase-to-phase short circuit?

A phase-to-phase short triggers simultaneous high-side and low-side over-current detection. The OCP circuit disables all six MOSFETs within 0.4µs (deglitch time), pulls nFAULT low, and holds outputs in high-impedance state for 2ms before auto-retrying. During the off period, synchronous rectification decays residual current safely through the body diodes or active LS-FETs.

Is an external bootstrap diode required for high-side drive?

No. The MP6541GQKT-P uses an internal charge pump (CP1/CP2/VCP) instead of bootstrap circuitry, eliminating the need for external diodes or timing constraints associated with bootstrap recharge. This allows reliable high-side drive at any duty cycle-including 0% and 100%-and simplifies PCB layout by removing high-voltage floating node routing.