Monolithic Power Systems Inc. MP6538GV-Z

Overview

MP6538GV-Z from Monolithic Power Systems is a three-phase BLDC motor pre-driver IC designed to control six N-channel MOSFETs in half-bridge configurations up to 100V bus voltage. It integrates Hall-sensor interface logic for 120° commutation, programmable over-current protection (OCP) via OCREF input, adjustable dead-time control (560ns–4.5µs), and internal charge-pump-assisted bootstrap gate drive. Used in e-bike controllers and power drills where precise timing, fault resilience, and thermal robustness are required.

For engineers reviewing the MP6538GV-Z datasheet, MP6538GV-Z pinout, MP6538GV-Z application, or MP6538GV-Z equivalent, this page delivers verified technical context on Hall-based commutation logic, CSO current-sense amplifier behavior, VBST UVLO threshold (4V), nFAULT open-drain fault signaling, and QFN-28 thermal pad layout-critical for motor control PCB layout and BOM validation.

Technical Context

The MP6538 implements sensor-based commutation using three Hall inputs (HA/HB/HC) spaced at 120° electrical degrees to determine rotor position and sequence gate drive outputs across three phases. Its logic interprets PWM, DIR, and nBRAKE signals to enable speed modulation, directional control, and active braking-where nBRAKE=0 forces all low-side gates on.

Gate drive relies on bootstrap capacitors charged during low-side conduction, with an internal charge pump sustaining high-side drive during extended high-state periods. Protection circuitry includes dual UVLO (VIN: 4.4V rising, VREG: 7.5V rising), thermal shutdown at 175°C with 20°C hysteresis, and OCP with 2.7µs deglitch time and latched fault recovery via nSLEEP or UVLO reset.

Key Specifications

Pinout & Package

MP6538GV-Z is housed in a thermally enhanced QFN-28 (4mm × 5mm) package with exposed thermal pad for efficient heat dissipation in motor driver PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STSPIN32F0B and TMC6300-LA, MP6538GV-Z delivers plug-and-play Hall-based commutation with minimal external components, lower gate drive latency, and built-in current-sense amplification-making it optimal for cost-sensitive, high-volume BLDC applications where deterministic timing and rapid fault response are prioritized over programmability.

Availability

MP6538GV-Z is available at Aetrix Electronics and suitable for e-bike motor controllers, cordless power tools, industrial fans, and conveyor belt drives requiring stable component supply, long-lifecycle assurance, and RoHS-compliant packaging.

Supply support for MP6538GV-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 core expertise in DC/DC conversion, motor control, and battery management.

The MP6538 belongs to MPS's motor pre-driver product line, engineered specifically for cost-effective, Hall-sensor-based BLDC systems in consumer and light-industrial applications where integration, reliability, and thermal efficiency are critical.

FAQ

What is the function of the CSO pin and how is it used in over-current protection?

CSO is the current-sense output pin that provides a 20× amplified voltage of the LSS-to-GND sense resistor voltage. During PWM on-time, it reflects motor phase current; when V_DS across the low-side FET exceeds the OCREF-set threshold, CSO is pulled to ~6V, triggering OCP after 2.7µs deglitch. The external RC network on CSO sets OCP off-time (t_OFF ≈ 0.6×R×C), enabling precise stall current limiting without MCU intervention.

How does the MP6538 handle extended high-side conduction without bootstrap capacitor recharge?

The MP6538 integrates a charge pump that actively replenishes charge on the bootstrap capacitor when the high-side FET remains on for extended periods. This prevents V_BST from dropping below the 4V UVLO threshold, ensuring uninterrupted high-side gate drive-unlike pure bootstrap-only drivers that fail under 100% duty cycle conditions.

Can the MP6538 operate without Hall sensors?

No-the MP6538's commutation logic is hardwired to require three 120°-spaced Hall inputs (HA/HB/HC). It does not support sensorless back-EMF detection or alternative commutation modes. For Hall-less operation, a different pre-driver such as the MP6540 (with optional Hall/sensorless mode) or a microcontroller-based solution is required.

What is the purpose of the LDO pin and when should an external NPN transistor be used?

The LDO pin outputs a regulated 12V supply derived from VIN, intended to drive external NPN transistors for high-current gate drive. When gate drive current exceeds ~5mA (e.g., driving high-Qg MOSFETs at >20kHz), the external NPN bypasses internal LDO power dissipation, preventing thermal overload and maintaining stable VREG under dynamic load.

How is dead-time configured and why is it critical for reliability?

Dead-time is set by connecting a resistor (R_DT) between the DT pin and GND, yielding t_DEAD = 0.044×R_DT(kΩ) + 0.1 µs (range: 77ns–4.5µs). It ensures non-overlapping HS/LS gate drive to prevent shoot-through current-a destructive condition where both FETs in a half-bridge conduct simultaneously, causing excessive power loss and potential device failure.

What happens during thermal shutdown and how is recovery performed?

At 175°C junction temperature, the MP6538 enters a latched fault state: all gate outputs disable, nFAULT pulls low, and operation halts. Recovery requires either toggling nSLEEP (low→high) or cycling VIN/VREG through UVLO thresholds. The 20°C hysteresis prevents oscillation near trip point, ensuring stable re-enablement only after die cools to ≤155°C.

Is the MP6538GV-Z RoHS-compliant and lead-free?

Yes-MP6538GV-Z is fully RoHS-compliant, lead-free, and halogen-free per MPS quality assurance standards. The QFN-28 package uses matte tin (Sn) lead finish and meets JEDEC J-STD-020 moisture sensitivity level 3 (MSL3) requirements for standard SMT assembly processes.