Monolithic Power Systems Inc. MP6520GV-Z

Overview

MP6520GV-Z from Monolithic Power Systems is a bipolar stepper motor driver IC with integrated dual full-bridge N-channel MOSFETs, microstepping translator, and 3.3V LDO regulator. It operates from 8V to 32V input, delivers up to ±1.5A per phase, supports full/half/quarter/eighth-step modes, and includes OCP/OVP/UVLO/thermal shutdown. Used in precision motion control for printers, CNC stages, and lab automation.

For engineers reviewing the MP6520GV-Z datasheet, MP6520GV-Z pinout, MP6520GV-Z application, or MP6520GV-Z equivalent, key selection criteria include its integrated gate drive charge pump, adjustable mixed-decay PWM current control, open-drain nFAULT/nHOME outputs, QFN-28 thermal pad layout, and logic-level compatibility with 3.3V/5V microcontrollers.

Technical Context

The MP6520GV-Z implements a constant-off-time (COT) PWM current regulation architecture with programmable blanking time (2µs) and crossover dead time (400ns), using external ROSC resistor to set off-time (20–40µs). Its internal DAC-driven translator sequences phase currents per step table, with MDS pin enabling voltage-controlled mixed-decay ratio (0–100% fast decay).

It integrates an internal charge pump (525kHz) driving high-side MOSFETs via VCP, with CPA/CPB pins requiring 100nF ceramic capacitor; VG supplies gate drive bias and requires 1µF bypass. The 3.3V reference (3.2–3.45V, 1mA load) powers logic and eliminates need for external VCC.

Key Specifications

Pinout & Package

MP6520GV-Z is housed in a thermally enhanced QFN-28 (4mm × 5mm) package with exposed GND pad on underside for PCB heat dissipation. Pin 1 is marked by index area; top marking includes MPS prefix, year/week code, part number, and lot ID.

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, MP6520GV-Z uniquely combines integrated MOSFETs, self-powered logic, comprehensive fault latching, and analog decay control-making it optimal for compact, reliable, and thermally constrained motion subsystems.

Availability

MP6520GV-Z is available at Aetrix Electronics and suitable for printer paper feed mechanisms, CNC milling axis drives, lab automation carousels, and 3D printer extruder control requiring stable component supply across production lifecycles.

Supply support for MP6520GV-Z 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 distribution since 1997.

The MP6520 belongs to MPS's integrated motor driver product line, engineered for compact, thermally efficient stepper control in space-constrained industrial and consumer motion systems without external gate drivers or logic supplies.

FAQ

What is the maximum allowable motor supply voltage for MP6520GV-Z?

The absolute maximum VIN rating is 40V, but the recommended operating range is 8V to 32V. Operation above 32V risks triggering the 36–40V input over-voltage protection (OVP), which disables outputs and asserts nFAULT. Sustained use beyond 32V is not advised due to reduced safety margin and potential reliability impact.

How does the MP6520GV-Z achieve thermal stability in QFN-28 packaging?

Thermal stability relies on the exposed GND pad soldered to a large PCB copper pour, achieving θ_JA = 40°C/W on a 4-layer board. Combined with thermal shutdown at 165°C and 30°C hysteresis, the device autonomously cycles off during overload, allowing safe cooldown before resuming operation without external intervention.

Can MP6520GV-Z drive unipolar stepper motors?

No. MP6520GV-Z is designed exclusively for bipolar stepper motors with center-tapped or dual-winding configurations. Its dual full-bridge topology requires four-terminal connection (A+, A−, B+, B−) and cannot interface with 5- or 6-wire unipolar motors without external rewiring or external transistor arrays.

What is the function of the nRSET pin, and how does it differ from nSLEEP?

nRSET resets the internal step table to home position (step 5) and ignores STEP inputs while asserted low; it does not power down circuitry. nSLEEP disables all internal blocks-including charge pump, 3P3VOUT, and translators-and reduces quiescent current to 5µA. Wake-up from sleep requires ≥1ms stabilization before issuing STEP.

Is an external pull-up resistor required for nFAULT and nHOME outputs?

Yes. Both nFAULT and nHOME are open-drain outputs with no internal pull-up. A 4.7kΩ to 10kΩ resistor to 3.3V or 5V is required to ensure valid logic-high levels when no fault occurs or home position is inactive. Missing pull-ups result in floating states and unreliable system-level fault detection.

How is current limit set, and what is the role of VREF in PWM regulation?

Current limit is set by VREF voltage applied to Pin 23 and external sense resistor R_SENSE, per I_LIMIT = V_REF × 5 / R_SENSE. VREF feeds a DAC that scales the current comparator threshold; at 3.3V VREF and 0.1Ω R_SENSE, full-scale current is 1.65A-matching the 1.5A rating with margin.

Does MP6520GV-Z support automatic decay mode, and how is it enabled?

Yes. Automatic decay activates when MDS voltage exceeds 2.8V. In this mode, the device selects slow decay for current increases and mixed decay (30% fast decay) for decreases-optimizing efficiency and torque consistency without MCU intervention or analog tuning.