Monolithic Power Systems Inc. MP6501AGF-P

Overview

MP6501AGF-P from Monolithic Power Systems is a bipolar stepper motor driver IC with integrated 2.5A N-channel MOSFET full-bridges, 8V–35V input range, microstepping translator (full/half/quarter/eighth-step), and on-chip 3.3V regulator. It delivers precise current control via external sense resistors and supports mixed/fast/slow decay modes for torque optimization in motion control systems.

For engineers reviewing the MP6501AGF-P datasheet, MP6501AGF-P pinout, MP6501AGF-P application, or MP6501AGF-P equivalent, key selection criteria include its TSSOP-28 EP package thermal performance, 220mΩ HS/LS R_DS(on), fault reporting via open-drain nFAULT, and compatibility with 3.3V/5V logic interfaces without auxiliary control supply.

Technical Context

The MP6501AGF-P implements a constant off-time PWM current regulation architecture with programmable blanking time (2µs) and crossover dead time (400ns), enabling stable current control across varying motor inductance and supply voltage. Its internal charge pump (525kHz) drives high-side MOSFETs using CPA/CPB/VCP pins and requires external 100nF and 1µF ceramic capacitors.

Microstepping resolution is set by MS1–MS3 logic inputs, generating 32 discrete current steps per electrical cycle; decay mode (slow/fast/mixed) is controlled by MDS voltage level, with automatic decay selecting 30% fast decay when current demand decreases. The translator synchronizes STEP rising edges with DIR polarity to sequence winding current vectors.

Key Specifications

Pinout & Package

TSSOP-28 EP (9.7mm × 6.4mm) with exposed thermal pad soldered to PCB ground plane for enhanced thermal dissipation (θ_JA = 32°C/W, θ_JC = 6°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar stepper motor driver applications.

Compared with TB6600HG and DRV8825, MP6501AGF-P uniquely combines integrated 3.3V regulation, dual open-drain status outputs (nFAULT/nHOME), and programmable mixed decay in a thermally optimized TSSOP-28 EP package-making it optimal for space-constrained, self-contained motion modules requiring autonomous fault handling and minimal support components.

Availability

MP6501AGF-P is available at Aetrix Electronics and suitable for 3D printer motion control, industrial CNC positioning, and medical infusion pump actuation requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for MP6501AGF-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 design centers in the US, China, and Taiwan.

The MP6501A product line targets embedded motion control applications requiring integrated FETs, microstepping, and robust protection-designed to replace discrete H-bridge + controller solutions in compact, thermally constrained systems.

FAQ

What is the maximum allowable motor supply voltage for MP6501AGF-P?

The absolute maximum VIN rating is 40V, but the recommended operating range is 8V to 35V. Exceeding 35V risks triggering the input over-voltage protection (OVP threshold = 37.9V typ.), which disables outputs and asserts nFAULT. For reliable operation, maintain VIN ≤35V with transient margin.

How does the MP6501AGF-P achieve current regulation without an external op-amp?

It uses internal PWM comparators that compare the voltage across external sense resistors (SENA/SENB) to a DAC-adjusted fraction of VREF. The DAC output is controlled by the microstep translator, enabling precise current waveform shaping per step position without external amplification.

Can the 3.3V regulator (3P3VOUT) power external logic circuits?

Yes-3P3VOUT delivers up to 1mA at 3.3V ±3.5% and is designed to power microcontroller I/O, optical encoders, or level-shifters. It must be decoupled with a 0.47µF ceramic capacitor to GND; loading beyond 1mA causes output droop and instability.

What thermal considerations apply to the TSSOP-28 EP package?

The exposed thermal pad must be soldered to a minimum 250mm² copper pour connected to PCB ground. With proper layout (4-layer board, JESD51-7), θ_JA = 32°C/W allows ~1.2W continuous dissipation at 25°C ambient. Above 1W, derating is required per TJ = TA + (PD × θJA).

How does the nRSET pin interact with the STEP and DIR signals?

nRSET is asynchronous and forces the translator to home position (step #1) regardless of current DIR or STEP state. During nRSET assertion, STEP edges are ignored and DIR has no effect. Release nRSET before issuing new STEP commands to ensure predictable sequencing.

Is the MP6501AGF-P compatible with 5V logic systems?

Yes-the logic inputs (STEP, DIR, MS1–MS3, nENBL, etc.) accept 3.3V or 5V CMOS levels: VIH = 2V min., VIL = 0.6V max. Internal 530kΩ pull-downs ensure defined states when un-driven, supporting direct connection to both 3.3V and 5V microcontrollers.

What happens during thermal shutdown, and how does recovery work?

When junction temperature exceeds 165°C, all MOSFETs disable and nFAULT pulls low. Recovery is automatic: once TJ falls below 135°C (30°C hysteresis), outputs re-enable after ~5ms delay. No external reset is needed, but repeated shutdowns indicate insufficient heatsinking or excessive load.