Monolithic Power Systems Inc. MP6508GR-P

Overview

MP6508GR-P from Monolithic Power Systems is a bipolar stepper motor driver IC integrating dual N-channel full-bridge MOSFETs, operating from 2.7V to 18V supply and delivering up to 1.2A per channel. It features internal charge pump, 250mΩ high-side/low-side R_DS(on), 1µA sleep current, and fault flag output for over-current and thermal shutdown events - used in compact, battery-powered motion control systems such as security camera pan-tilt mechanisms.

For engineers reviewing the MP6508GR-P datasheet, MP6508GR-P pinout, MP6508GR-P application, or MP6508GR-P equivalent, key selection criteria include its integrated full-bridge architecture, 1.2A continuous output capability, QFN-16 (4mm×4mm) thermally enhanced package with exposed pad, and support for both external PWM and internal constant-off-time current regulation.

Technical Context

The MP6508GR-P implements two independent full-bridge drivers with synchronous rectification during slow-decay freewheeling, reducing conduction loss versus body-diode decay. Its internal charge pump enables high-side N-MOSFET gate drive without external bootstrap components.

Current regulation operates via either externally applied logic-level PWM signals on AIN1/AIN2/BIN1/BIN2 or internal constant-off-time (21–31µs) control using external sense resistors (R_SENSE) and a 204mV typical V_REF threshold. Blanking time (2.5µs) prevents false OCP triggering during switching transients.

Key Specifications

Pinout & Package

MP6508GR-P uses a 4mm×4mm QFN-16 package with exposed thermal pad (connected to GND), optimized for PCB heat dissipation in space-constrained applications. Pin numbering follows JEDEC MO-220 VGGC standard.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TB6600HG and DRV8825, MP6508GR-P delivers optimal balance of integration density, wide-input flexibility, and ultra-low sleep current - making it uniquely suitable for portable, battery-sensitive stepper applications where board space and energy efficiency are primary constraints.

Availability

MP6508GR-P is available at Aetrix Electronics and suitable for POS printers, video security cameras, digital still cameras, and battery-powered toys requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for MP6508GR-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 mixed-signal ICs for power management, motor control, and automotive applications.

The MP6508 product line targets compact, energy-efficient motion control systems - designed specifically to replace discrete H-bridge solutions in battery-powered and thermally constrained applications.

FAQ

What is the maximum motor supply voltage supported by MP6508GR-P?

The MP6508GR-P supports an absolute maximum VIN of 20V, with recommended operation from 2.7V to 18V. Exceeding 18V risks violating the BST-to-VIN voltage limit (≤6.5V) and may trigger UVLO or damage internal charge pump circuitry. Stable 12V or 16.8V LiPo inputs are commonly used in field deployments.

Does MP6508GR-P support microstepping?

No - MP6508GR-P natively supports only full-step and half-step excitation modes via logic-level input sequencing on AIN1/AIN2/BIN1/BIN2. It lacks internal indexer or microstepping DAC; true microstepping requires external controller generation of intermediate current levels.

How is thermal performance affected by the exposed pad connection?

The exposed thermal pad must be soldered to a solid GND copper plane ≥100mm² to achieve θ_JA = 46°C/W. Leaving it unconnected raises junction temperature by >35°C at 1.2A, potentially triggering thermal shutdown during sustained operation.

Can MP6508GR-P drive two independent DC motors?

Yes - its dual full-bridge architecture allows independent control of two brushed DC motors. Each bridge accepts separate PWM inputs (AIN1/AIN2 for motor A; BIN1/BIN2 for motor B), enabling forward/reverse and braking functions without shared timing constraints.

What is the purpose of the BST pin and required external component?

BST is the charge pump output that generates boosted gate drive voltage for high-side N-MOSFETs. A 10nF–100nF ceramic capacitor must connect between BST and VIN to sustain gate voltage ≥VIN+5V; insufficient capacitance causes high-side FET turn-on failure and erratic motor behavior.

Is the FAULT pin actively driven or open-drain?

The FAULT pin is an open-drain output. It pulls low during over-current or thermal shutdown events and floats otherwise. An external pull-up resistor (typically 10kΩ to VDD or MCU IO voltage) is mandatory to establish valid logic-high state for fault detection.

How does the internal blanking time prevent false over-current trips?

A 2.5µs internal blanking window disables the current sense comparator immediately after bridge switching, suppressing transient spikes from MOSFET body diode reverse recovery or PCB parasitics. This ensures only sustained over-current conditions trigger protection, avoiding nuisance shutdowns during normal commutation.