Monolithic Power Systems Inc. MP6531AGF

Overview

MP6531AGF from Monolithic Power Systems is a three-phase brushless DC 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 current per high-side output, and integrates programmable over-current protection with 3µs deglitch time for motor phase fault detection in power drills and e-bikes.

For engineers reviewing the MP6531AGF datasheet, MP6531AGF pinout, MP6531AGF application, or MP6531AGF equivalent, this device requires attention to bootstrap capacitor sizing (0.1–1µF), dead-time resistor selection (10kΩ–100kΩ), LSS shunt resistor calibration (e.g., 50mΩ for 10A OCP), and thermal pad soldering for TSSOP-28 EP package reliability.

Technical Context

The MP6531AGF implements a charge-pump-based VREG regulator (10–13V output) to sustain gate drive under low VIN conditions and uses an internal trickle-charge circuit to maintain bootstrap voltage during 100% duty-cycle operation. It enforces shoot-through prevention via adjustable dead time (130ns–5.7µs) set by an external resistor on DT pin.

Protection logic includes dual-path over-current sensing: VDS-based short-circuit detection referenced to OCREF pin (0.125–2.4V threshold) and LSS-based low-side current monitoring with 0.4–0.6V trip level. Faults trigger latched shutdown with open-drain nFAULT assertion and require nSLEEP or VIN UVLO reset.

Key Specifications

Pinout & Package

MP6531AGF is housed in a thermally enhanced 28-pin TSSOP-EP package (9.7mm × 6.4mm) with exposed thermal pad on underside for PCB copper pour attachment. Pin numbering follows standard TSSOP convention with pin 1 at top-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP6531AGF, MP6532AGF adds system-level integration at minor IQ cost, while DRV8305PWP trades duty-cycle headroom and fault coverage for cost-sensitive 45V-class applications - neither matches MP6531AGF's 60V capability and dual OCP architecture.

Availability

MP6531AGF is available at Aetrix Electronics and suitable for power drills, impact drivers, and e-bike controllers requiring stable component supply, long-lifecycle availability, and RoHS-compliant packaging.

Supply support for MP6531AGF 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 design centers in the US, China, and Taiwan.

The MP6531A product line targets high-efficiency, high-reliability motor control in portable and industrial equipment, emphasizing integrated protection, wide input range, and thermal robustness for ruggedized applications.

FAQ

What is the minimum recommended bootstrap capacitor value for MP6531AGF?

The minimum bootstrap capacitance is calculated as C_BOOT > 8 × Q_G, where Q_G is the MOSFET's total gate charge in nC. For typical Q_G = 30nC, C_BOOT > 240nF. MPS recommends 0.1µF–1µF X7R/X5R ceramic capacitors rated for ≥25V, placed close to BSTx and SHx pins.

How does the MP6531AGF handle 100% duty-cycle operation without losing high-side gate drive?

It uses an internal trickle-charge circuit that supplies ~5µA to each bootstrap capacitor during high-side conduction, compensating for leakage and maintaining sufficient gate voltage. This eliminates reliance on low-side switching for bootstrap recharge, enabling true 100% duty-cycle capability.

Can MP6531AGF drive both N-channel and P-channel high-side MOSFETs?

No - MP6531AGF is designed exclusively for N-channel high-side MOSFETs in bootstrap configuration. Its gate drivers lack the negative voltage swing or level-shifting capability required for P-channel devices. External high-side drivers would be needed for P-MOSFET implementations.

What happens when both HA and LA inputs are driven high simultaneously?

The MP6531AGF enforces positive dead time: when both HA and LA are high, all outputs go to high-impedance state. This prevents shoot-through by ensuring neither high-side nor low-side FET turns on until the complementary signal transitions low, as defined in the input logic truth table.

Is the TSSOP-28 EP package of MP6531AGF compatible with standard reflow profiles?

Yes - the MP6531AGF TSSOP-28 EP package is qualified for JEDEC J-STD-020D moisture sensitivity level 3 and supports standard lead-free reflow profiles (peak 260°C). The exposed thermal pad must be soldered to a minimum 100mm² copper pour with ≥4 thermal vias for thermal performance and mechanical reliability.

How is over-current protection disabled if not required in the application?

OCP can be disabled by connecting a 100kΩ resistor from VREG to the OCREF pin. This pulls OCREF to ~11.5V, exceeding the maximum 2.4V comparator threshold and preventing false triggering. LSS should be tied directly to ground if shunt-based OCP is unused.

Does MP6531AGF support sensorless BLDC commutation directly?

No - MP6531AGF is a pre-driver only and does not include Hall sensor interfaces, back-EMF detection circuitry, or commutation logic. It requires an external MCU or dedicated BLDC controller to generate the six PWM signals (HA/HB/HC/LA/LB/LC) based on rotor position feedback.