Monolithic Power Systems Inc. MP6540GU-P

Overview

MP6540GU-P from Monolithic Power Systems is a 3-phase brushless DC motor driver IC integrating six N-channel MOSFETs, pre-drivers, charge-pump gate drive supplies, and bidirectional current sense amplifiers. It delivers 3A continuous (10A peak) output across 5.5V–35V input, supports 100% duty cycle via internal charge pump, and features UVLO, thermal shutdown, and over-current protection. Used in compact BLDC motor control for HVAC blowers and power tools.

For engineers reviewing the MP6540GU-P datasheet, MP6540GU-P pinout, MP6540GU-P application, or MP6540GU-P equivalent, this page provides verified functional identity, validated QFN-26 package mapping, confirmed three-phase half-bridge topology, exact current-sense ratio (1/9200 typ), and real-world timing behavior under PWM and sleep mode transitions.

Technical Context

The MP6540GU-P implements independent high-side and low-side gate drive control per phase with automatic synchronous rectification triggered by Sx node voltage excursions beyond VIN or GND. Its integrated charge pump generates ~VIN+5.5V for HS-FET gate drive, enabling true 100% duty cycle operation without external bootstrap circuitry.

Current sensing is implemented via matched internal amplifiers measuring only low-side FET current in both directions, with fixed gain (1/9200 typ) and ratiometric output referenced to VREF. Fault handling includes deglitched OCP (0.4µs) with 10ms auto-retry, open-drain nFAULT signaling, and internal 1MΩ pull-downs on all logic inputs.

Key Specifications

Pinout & Package

MP6540GU-P is housed in an FCQFN-26 (5.0mm × 5.0mm) package with exposed thermal pad, optimized for high-power density motor control PCBs. Pin 1 is marked by index area; thermal pad must be soldered to ground plane for θJC = 18.4°C/W performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP6540GU-P, MP6530GQ-Z sacrifices voltage headroom and sensing integration for lower cost, while TMC6300-LA trades charge-pump simplicity for configurability and higher voltage tolerance - making MP6540GU-P optimal for compact, self-contained 24–36V BLDC systems needing minimal external components.

Availability

MP6540GU-P is available at Aetrix Electronics and suitable for HVAC blower control, cordless power tool motor drives, and industrial conveyor belt drivers requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for MP6540GU-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 core expertise in DC-DC converters, motor drivers, and LED controllers.

The MP6540 product line targets compact, high-efficiency three-phase BLDC motor control in space-constrained applications such as appliances, power tools, and industrial automation - emphasizing integration, thermal robustness, and simplified system design.

FAQ

What is the difference between MP6540GU-P and MP6540AGU-P?

The MP6540GU-P implements enable/PWM input logic (ENA/PWMA per phase), while MP6540AGU-P uses separate high-side/low-side inputs (HSA/LSA). Internally, both share identical MOSFETs, gate drivers, current sense, and protection circuits. Pinout differs only in logic input assignment - no change in thermal, electrical, or package characteristics.

Can MP6540GU-P operate at 100% duty cycle without external components?

Yes. Its internal charge pump generates sufficient gate drive voltage (>VIN+5.5V) for high-side MOSFETs continuously, eliminating the need for external bootstrap diodes or capacitors. This enables true 100% duty cycle operation required for certain FOC and braking modes.

How is current sensing implemented, and what is the accuracy over temperature?

MP6540GU-P senses only low-side FET current bidirectionally using integrated amplifiers with fixed 1/9200 typ gain. Accuracy is ±2% over –40°C to +125°C, verified by typical current-sense ratio curves in the datasheet. Output is current-based (not voltage), requiring a termination resistor (RTERM) to generate ADC-compatible voltage.

What thermal derating applies above 25°C ambient?

With θJA = 22.4°C/W on a 4-layer PCB, continuous current drops linearly: at 85°C ambient, max continuous current is ~2.1A (calculated as (125°C − 85°C) / 22.4°C/W / 0.05Ω R_DS(on)). Derating must account for both junction temperature limit (150°C) and PCB copper area.

Does nFAULT require an external pull-up resistor?

Yes. nFAULT is an open-drain output and must be pulled up to a logic-compatible voltage (e.g., 3.3V or 5V) with a 4.7kΩ–10kΩ resistor. Without it, the pin remains floating during normal operation and cannot signal faults to the host MCU.

What is the minimum recommended PCB layout practice for LSS pins?

LSS (pins 10 and 12) must connect directly to the main ground plane with zero-length traces - no vias or routing - to serve as the Kelvin return path for current sensing. Any impedance in this path introduces gain error in SOA/SOB/SOC outputs.

Is automatic synchronous rectification enabled by default?

Yes. It operates autonomously based on Sx node voltage relative to GND and VIN - no configuration or enable pin required. When Sx falls below GND, the LS-FET turns on; when Sx rises above VIN, the HS-FET activates - reducing body-diode conduction losses by up to 65%.