Monolithic Power Systems Inc. MP6517GJS-XXXX-P

Overview

MP6517GJS-XXXX-P from Monolithic Power Systems is a programmable single-phase BLDC motor driver IC with integrated Hall sensor, power MOSFETs (850 mΩ total R_DS(on)), and reverse voltage protection. It delivers up to 1.2 A output current limit, operates from 3.3 V to 18 V, and provides programmable speed vs. PWM duty response for CPU fan control in servers and desktops.

For engineers reviewing the MP6517GJS-XXXX-P datasheet, MP6517GJS-XXXX-P pinout, MP6517GJS-XXXX-P application, or MP6517GJS-XXXX-P equivalent, key selection factors include its TSOT23-6-SL package, 26 kHz fixed switching frequency, soft on/off phase transition timing (1.45°–45°), rotor lock detection (0.6 s timeout), and I²C-capable FG/RD and PWM pins for register configuration.

Technical Context

The MP6517GJS-XXXX-P implements a Hall-based commutation controller with programmable θ_e delay (0°–15°) between Hall edge and current zero-crossing, enabling precise BEMF alignment. Its internal PLL locks to winding current zero-crossing during steady-state operation, reducing torque ripple and audible noise.

It integrates dual N-channel MOSFET half-bridge drivers (R_HSON = 520 mΩ, R_LSON = 330 mΩ), a 7 MHz oscillator, and OTP-programmable registers for startup current limit (320–1265 mA), soft-switching angles, and FG output scaling (1×/0.5×/2× Hall frequency). The FG/RD pin serves as open-drain speed indicator or rotor lock fault flag.

Key Specifications

Pinout & Package

MP6517GJS-XXXX-P is housed in a thermally enhanced TSOT23-6-SL package (0.95 mm height, 2.9 mm × 1.6 mm footprint), optimized for high-density fan module layouts and improved heat dissipation over standard TSOT23-6.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP6517GJS-XXXX-P, MP6515GJS-Z trades Hall integration for lower unit cost and simpler layout, while DRV10970PWP offers higher current headroom at the expense of programmability, acoustic optimization, and compactness-making MP6517GJS-XXXX-P optimal for space-constrained, noise-sensitive, and self-contained fan modules.

Availability

MP6517GJS-XXXX-P is available at Aetrix Electronics and suitable for CPU fan control, server chassis cooling, embedded industrial fan systems, and network equipment thermal management requiring stable component supply and long-term lifecycle support.

Supply support for MP6517GJS-XXXX-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 MP6517 belongs to MPS's integrated motor driver product line, engineered specifically for compact, intelligent, and self-monitoring brushless DC fan applications in computing and communications infrastructure.

FAQ

What is the purpose of the THETA_E register (0x0F[3:0])?

The THETA_E register sets the electrical angle delay (0°–15°, 1° per step) between the raw Hall sensor edge and the generated HA_OUT signal used for commutation timing. This compensates for mechanical misalignment between the Hall sensor and motor poles, ensuring optimal BEMF-current phase alignment and maximizing torque efficiency.

Can MP6517GJS-XXXX-P drive a three-phase BLDC motor?

No. MP6517GJS-XXXX-P is strictly a single-phase BLDC driver with one half-bridge (OUT1/OUT2) and one integrated Hall sensor. It lacks the three-phase gate drive logic, Hall input channels, and commutation state machine required for three-phase motors. It is designed exclusively for single-coil axial fans.

How does the rotor lock detection recover after triggering?

Upon rotor lock detection (no Hall edge for 0.6 s), MP6517GJS-XXXX-P disables the H-bridge and pulls FG/RD low. After a programmable off-time (1.8–3.6 s, set by RLOCK_SEL bits), it automatically attempts restart. Recovery completes only after detecting three consecutive Hall edges, confirming rotor motion has resumed.

What is the role of the SUCL register (0x0A[2:0]) during fan startup?

The SUCL register configures the initial current limit during spin-up (320–1265 mA in 135 mA steps). The IC ramps this limit in 16 steps over ~250 ms to avoid inrush current, then holds the programmed value. This prevents stalling and ensures reliable start under static load or low-temperature conditions.

Is the FG/RD pin compatible with 5 V microcontrollers?

Yes. FG/RD is an open-drain output with 1 µA leakage and 0.35 V low-level voltage at 3 mA sink current. When pulled up to 5 V via an external resistor (e.g., 10 kΩ), it safely interfaces with 5 V logic without level-shifting, provided the pull-up voltage does not exceed VCC + 0.3 V.

Does MP6517GJS-XXXX-P support I²C write operations in normal operation?

No. I²C functionality (SCL/SDA on FG/RD and PWM pins) is only active in test mode, entered by applying a negative pulse to PWM with specific timing. In normal operation, those pins retain their primary functions (tach output/fault flag and PWM input), and registers are read-only unless re-entering test mode.

What thermal derating applies to the 1.25 W power dissipation rating?

The 1.25 W rating assumes T_A = +25°C and θ_JA = 100°C/W on a 4-layer PCB (JESD51-7). At 85°C ambient, maximum continuous power drops to 0.85 W ((150 − 85)/100). Derating is linear; exceeding T_J = 150°C triggers thermal shutdown with 25°C hysteresis.