Monolithic Power Systems Inc. MP6541AGQKT-Z

Overview

MP6541AGQKT-Z from Monolithic Power Systems is a three-phase brushless DC (BLDC) motor power stage integrating six N-channel MOSFETs (15 mΩ HS/LS R_DS(on)), three half-bridge drivers, six pre-drivers, two gate drive supplies, and three bidirectional current-sense amplifiers. It delivers 8 A continuous output current at 40 V max input, supports 100% duty cycle via internal charge pump, and targets compact BLDC motor control in HVAC blowers and power tools.

For engineers reviewing the MP6541AGQKT-Z datasheet, MP6541AGQKT-Z pinout, MP6541AGQKT-Z application, or MP6541AGQKT-Z equivalent, key selection criteria include its TQFN-26 package thermal performance (θ_JA = 21.4°C/W), HS/LS independent logic inputs, integrated OCP thresholds (10–19 A HS, 17.5–25 A LS), and synchronous rectification for inductive load decay.

Technical Context

The MP6541AGQKT-Z implements independent high-side (HSA/HSB/HSC) and low-side (LSA/LSB/LSC) logic inputs per phase, enabling precise commutation timing and dead-time control without external logic. Its internal charge pump generates V_CP ≈ VIN + 5 V to sustain high-side gate drive at 100% duty cycle, backed by a trickle-charge circuit.

Three integrated current-sense amplifiers provide bidirectional phase current monitoring with typical gain ratios of 1/11,600 (A), 1/11,500 (B), and 1/11,000 (C), referenced to V_REF and compatible with MCU ADCs via external termination resistors. Fault handling includes open-drain nFAULT signaling for UVLO (4.4 V threshold), OVP (48 V), thermal shutdown (150°C), and deglitched OCP (0.4 µs).

Key Specifications

Pinout & Package

TQFN-26 (6 mm × 6 mm) package with exposed thermal pad; 0.5 mm pitch, MSL Level 1, RoHS-compliant lead-free finish.

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, the MP6541AGQKT-Z offers superior timing flexibility for field-oriented control, while STSPIN32F0A trades integration depth for higher voltage capability and embedded processing - neither matches the MP6541AGQKT-Z's combination of 8 A current, integrated current sensing, and HS/LS logic in a 40 V-class device.

Availability

MP6541AGQKT-Z is available at Aetrix Electronics and suitable for HVAC blower fan control, power tool motor drives, industrial conveyor belt drivers, and electric bicycle mid-drive controllers requiring stable component supply and long-term production continuity.

Supply support for MP6541AGQKT-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, including DC/DC converters, motor drivers, and LED drivers, with global manufacturing and quality certifications.

The MP6541A product line delivers integrated three-phase power stages for BLDC and PMSM motors, designed specifically for space-constrained, thermally demanding applications where discrete MOSFET solutions would increase board area and complexity.

FAQ

What is the maximum allowable junction temperature for MP6541AGQKT-Z, and how does thermal shutdown recover?

The absolute maximum junction temperature is 150°C. When exceeded, all MOSFETs disable and nFAULT pulls low. Recovery occurs automatically once die temperature falls to approximately 125°C (25°C hysteresis), restoring normal operation without external reset.

Can MP6541AGQKT-Z operate with a 12 V supply, and what is its minimum input voltage?

Yes, it operates from 4.75 V to 40 V. At 12 V input, it delivers full 8 A continuous current provided thermal design (PCB copper, vias, ambient) maintains junction temperature below 125°C. Quiescent current drops to 1 µA in sleep mode.

How does the current-sense amplifier interface with an MCU ADC, and what termination resistor is recommended?

SOA/SOB/SOC are current-source outputs referenced to VREF. Use a 5 kΩ resistor between each SOx and VREF (typically 5 V) to generate 0–5 V output swing. With 1/11,600 gain, this yields ~575 mV per 10 A, matching standard 12-bit ADC resolution.

What external capacitors are mandatory for stable operation, and what are their ratings?

Three capacitors are required: (1) 4.7–10 µF X7R ceramic from VG to GND (10 V rating); (2) 1 µF X7R from VCP to VIN (16 V rating); (3) 100 nF X7R between CP1 and CP2 (rated ≥VIN). All must be placed within 2 mm of respective pins.

Does MP6541AGQKT-Z support 100% duty cycle, and how is high-side gate drive sustained?

Yes, via an internal 2 MHz charge pump generating VCP ≈ VIN + 5 V. A trickle-charge circuit maintains sufficient gate voltage during 100% duty cycle, eliminating bootstrap diode limitations and enabling true high-side saturation without external components.

What fault conditions trigger the nFAULT pin, and is it latched or auto-recovering?

nFAULT activates for UVLO (VIN < 4.4 V), OVP (VIN > 48 V), thermal shutdown (>150°C), or OCP (current > threshold for >0.4 µs). It is auto-recovering: after OCP, outputs disable for 2 ms then resume; UVLO/OVP clear immediately upon voltage return to valid range.

How does automatic synchronous rectification function during inductive flyback?

When both HS and LS FETs are off and SA/SB/SC voltage drops below GND, the LS-FET turns on to conduct recirculating current; if voltage exceeds VIN, the HS-FET turns on. This replaces lossy body-diode conduction, reducing heat and improving efficiency at partial loads.