Monolithic Power Systems Inc. MP6509GF-P

Overview

MP6509GF-P from Monolithic Power Systems is a bipolar stepper motor driver IC with dual integrated N-channel full-bridge MOSFETs, delivering up to 1.2A per channel across a 2.7V–18V supply range. It supports external PWM or internal constant-off-time current control, features four selectable current attenuation modes (20%–100%), and includes over-current protection, thermal shutdown, UVLO, and fault flag output. Used in compact motion-control systems such as POS printers and battery-powered cameras.

For engineers reviewing the MP6509GF-P datasheet, MP6509GF-P pinout, MP6509GF-P application, or MP6509GF-P equivalent, this page provides verified technical context, real-world design meanings for key specs, validated pin functions, application-specific implementation guidance, and confirmed alternative parts with documented functional differences.

Technical Context

The MP6509GF-P implements two independent full-bridge drivers using eight internal N-channel MOSFETs with matched 250mΩ HS/LS on-resistance at 9V and 25°C. Its internal charge pump enables high-side gate drive without external bootstrap components, supporting operation down to 2.7V input.

It offers dual control modes: external logic-level PWM input via AIN1/AIN2/BIN1/BIN2 pins, or internal constant-off-time (21–31µs) current regulation using SENA/SENB sense resistors and ATT1/ATT2-configurable VREF attenuation (15–233mV trip thresholds). Fault detection is independent of sense resistor value and triggers open-drain FAULT pin assertion.

Key Specifications

Pinout & Package

The MP6509GF-P is housed in a thermally enhanced 20-pin TSSOP-EP package (6.5mm × 6.4mm) with an exposed thermal pad on the underside, enabling ≥3.1W power dissipation at TA = 25°C (θJA = 40°C/W).

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, the MP6509GF-P uniquely balances wide input voltage (2.7–18V), ultra-low sleep current (1µA), and on-the-fly hold-current scaling-making it optimal for portable, battery-constrained, and thermally restricted stepper applications where full microstepping is not required.

Availability

MP6509GF-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-lifecycle support, and RoHS-compliant packaging.

Supply support for MP6509GF-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, and global manufacturing partnerships.

The MP6509 belongs to MPS's motor driver product line, engineered specifically for compact, efficient bipolar stepper control in space- and power-constrained consumer and industrial motion systems.

FAQ

What is the maximum allowable motor supply voltage for MP6509GF-P?

The absolute maximum VIN rating is 20V, but the recommended operating range is 2.7V to 18V. Operation above 18V risks exceeding safe junction temperature under load due to increased conduction and switching losses, especially in the TSSOP-20 EP package without forced airflow.

Can MP6509GF-P drive unipolar stepper motors?

No-it is designed exclusively for bipolar stepper motors or dual DC motors. Its dual full-bridge topology requires four-wire (2-phase) bipolar windings; unipolar motors (5/6-wire) require center-tapped configurations incompatible with the MP6509GF-P's output architecture.

How does the internal charge pump function without external components?

The charge pump generates a boosted gate-drive voltage (VIN + ~5V) using an internal oscillator and flying capacitor switched between VIN and BST pin. A single 10nF–100nF ceramic capacitor from BST to VIN completes the circuit, enabling high-side N-MOSFET turn-on down to 2.7V input.

What happens when both AIN1 and AIN2 are held high simultaneously?

Per Table 1 in the datasheet, AIN1=H and AIN2=H forces both AOUT1 and AOUT2 to GND (short-brake mode), causing rapid current decay and motor braking. This state is valid and used for controlled stopping-but sustained use increases power dissipation in the low-side MOSFETs.

Is the FAULT pin compatible with 3.3V microcontrollers?

Yes-the FAULT pin is open-drain with 200mV max VOL at 1mA sink, allowing direct connection to 3.3V or 5V GPIO inputs using a pull-up resistor. No level-shifting is needed, and the pin asserts low for both over-current and thermal shutdown events.

Does MP6509GF-P support microstepping?

No-it supports only full-step and half-step excitation via external logic sequencing of AIN1/AIN2/BIN1/BIN2. Microstepping requires external current DACs or dedicated indexer ICs; the MP6509GF-P provides only amplitude-controlled current regulation within those discrete step modes.

How is thermal performance affected by the exposed pad connection?

The exposed thermal pad must be soldered to a minimum 100mm² copper pour tied to GND for θJA = 40°C/W. Without this, θJA degrades to >60°C/W, reducing max continuous power from 3.1W to <2W at 25°C ambient-potentially triggering thermal shutdown at 1.2A load.