Monolithic Power Systems Inc. MP6531AGF-P

Overview

MP6531AGF-P from Monolithic Power Systems is a three-phase BLDC motor pre-driver IC that controls six external N-channel MOSFETs in half-bridge configuration, supports 5V–60V input voltage, delivers 0.8A source / 1A sink gate drive per high-side output, and integrates bootstrap charge pump with trickle-charge for 100% duty-cycle operation. It is used in e-bike motor controllers where compact size, thermal robustness, and fault resilience are critical.

For engineers reviewing the MP6531AGF-P datasheet, MP6531AGF-P pinout, MP6531AGF-P application, or MP6531AGF-P equivalent, key selection criteria include bootstrap capacitor support for continuous high-side conduction, programmable over-current protection via LSS shunt sensing, adjustable dead-time control to prevent shoot-through, and integrated thermal shutdown with latched fault reporting on nFAULT.

Technical Context

The MP6531AGF-P implements a three-phase gate driver architecture with independent high-side (GHA/GHB/GHC) and low-side (GLA/GLB/GLC) outputs, each driven by dedicated logic inputs (HA/HB/HC and LA/LB/LC). It uses an internal charge pump to generate VREG (10–13V) from VIN ≥5V, enabling full gate drive even at low input voltages.

Protection is implemented via dual-path current sensing: VDS-based short-circuit detection referenced to OCREF (0.125V–2.4V), and LSS-based over-current protection with 0.5V threshold; both trigger latched fault shutdown. Dead time (0.13ns–5.7µs) is set externally via resistor on DT pin, and nSLEEP enables sub-1µA sleep mode with automatic power-up sequence.

Key Specifications

Pinout & Package

MP6531AGF-P is housed in a thermally enhanced 28-pin TSSOP-EP package (9.7mm × 6.4mm) with exposed pad for PCB-level heat dissipation. The package supports 3.9W continuous power dissipation at +25°C ambient.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP6531AGF-P, MP6532AGF-P offers tighter OCP accuracy and integrated sensing, while DRV8305PWP trades duty-cycle headroom and bootstrap robustness for lower cost and built-in current amplification - making MP6531AGF-P optimal for 48V+ e-bike and industrial BLDC systems demanding full-range operation and thermal resilience.

Availability

MP6531AGF-P is available at Aetrix Electronics and suitable for e-bike motor controllers, cordless power tools, and industrial PMSM drives requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for MP6531AGF-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 analog and power ICs, with core expertise in DC/DC conversion, motor control, and interface solutions.

The MP6531A product line delivers integrated three-phase pre-drivers optimized for compact, thermally constrained BLDC applications in portable and battery-powered equipment - emphasizing robust gate drive, fault resilience, and wide-input flexibility.

FAQ

What is the maximum bootstrap capacitor value supported by MP6531AGF-P?

The MP6531AGF-P supports bootstrap capacitors from 0.1µF to 1µF. Capacitors exceeding 1µF may cause improper startup behavior due to excessive inrush into the bootstrap node. Recommended values are 0.22µF–0.47µF X7R/X5R ceramics rated for ≥25V, sized using C_BOOT > 8×Q_G (nF) where Q_G is the MOSFET's total gate charge in nC.

How does the trickle-charge circuit enable 100% duty-cycle operation?

The internal trickle-charge circuit supplies ~5µA to each bootstrap capacitor during high-side conduction, compensating for leakage and maintaining sufficient gate voltage (≥10V) even when the low-side FET remains off indefinitely. This eliminates reliance on periodic low-side conduction for bootstrap recharge, enabling true 100% duty-cycle high-side drive.

Can MP6531AGF-P drive 100V MOSFETs?

No. MP6531AGF-P is rated for 60V maximum input (VIN) and 65V absolute max on SHA/SHB/SHC pins. Driving 100V MOSFETs exceeds its voltage ratings and risks permanent damage. For 100V systems, use gate drivers qualified to ≥100V, such as MPS MPQ6530 or Infineon 2EDN7524.

What happens during simultaneous high- and low-side logic assertion (e.g., HA = LB = 1)?

When both high- and low-side inputs for the same phase are asserted, the MP6531AGF-P enforces positive dead time: it disables both outputs and holds them in high-impedance state until one input is deasserted. This prevents shoot-through regardless of external logic timing errors or MCU glitches.

Is the nFAULT output compatible with 3.3V microcontrollers?

Yes. nFAULT is an open-drain output with 1µA max high-state leakage. When pulled up to 3.3V via a 10kΩ external resistor, it reliably signals faults to 3.3V GPIOs. The output sinks ≥5mA when active, ensuring solid low-level assertion even with typical PCB trace capacitance.

Does MP6531AGF-P require external bootstrap diodes?

No. The MP6531AGF-P integrates internal bootstrap diodes (VF_BOOT = 0.9V @ 10mA) between VREG and each BSTx pin. External diodes are unnecessary and would interfere with the internal trickle-charge path; only ceramic bootstrap capacitors are required.

How is thermal shutdown reset after activation?

Thermal shutdown is latched: the device remains disabled until either VIN drops below UVLO threshold (≤3.3V) and recovers, or nSLEEP is toggled low-then-high. Simply removing thermal stress does not auto-recover - intentional reset is required to ensure safe re-entry into operation.