MTD6508 3-Phase Sinusoidal Sensorless Brushless DC Fan Motor Driver Features Description 180 Sinusoidal Drive for High Efficiency and Low The MTD6508 device is a 3-phase, full-wave Acoustic Noise sensorless driver for brushless DC (BLDC) motors. It features a 180 sinusoidal drive, high torque output and Position Sensorless BLDC Drivers silent drive. With adaptive features, parameters and a (no Hall Effect Sensor required) wide range of power supplies (2V to 5.5V), the Integrated Power Transistors MTD6508 is intended to cover a broad range of motor Supports 2V to 5.5V Power Supplies characteristics while requiring minimum external Variable Programming Resistor (R ) Setting PROG components. Speed control can be achieved through to fit Motor Constant (K ) Range from 3.25 mV/ M either power supply modulation (PSM) or pulse-width Hz to 52 mV/Hz modulation (PWM). Speed Control through Power Supply Modulation Compact packaging and a minimal bill of materials (PSM) and/or Pulse-Width Modulation (PWM) make the MTD6508 device extremely cost-efficient in Built-in Frequency Generator: FG, FG/3 Output fan applications. For example, the CPU cooling fans in Signal (FG/2 and FG/6 Option are available upon notebook computers require designs that provide low request) acoustic noise, low mechanical vibration and are highly Output PWM Slew Rate Control Programmable efficient. The frequency generator (FG) output enables with an External Resistor for Start-up precision speed control in closed-loop applications. (Adjustable version) The MTD6508 device includes Lock-up Protection Phase Target Selection for Regulation mode to turn off the output current when the motor is in (Adjustable Version) a lock condition, with an automatic recovery feature to Start-up Strength Selection (Adjustable Version) restart the fan when the lock condition is removed. Start-up Output Current Controlled by PWM Motor overcurrent limitation and thermal shutdown protection are included for safety-enhanced operations. Output Current Soft Start The MTD6508 is available in compact, thermally- Built-in Lock-up Protection and Automatic enhanced, 10-Lead 3mmx3mmx0.5mm UDFN Recovery Circuit packages and 16-Lead 4mmx4mmx0.5mm Built-in Overcurrent Limitation UQFN packages. Built-in Thermal Shutdown Protection Built-in Overvoltage Protection Low Minimal Start-up Speed for Low-Speed Operation Packages: - 10-Lead 3 mm x 3 mm x 0.5 mm UDFN - 16-Lead 4 mm x 4 mm x 0.5 mm UQFN (Adjustable version) Applications Notebook CPU Cooling Fans 5V 3-Phase BLDC Motors 2015 Microchip Technology Inc. DS20005359A-page 1MTD6508 Package Types MTD6508 MTD6508 4x4 UQFN-16* 3x3 UDFN-10* 16 15 14 13 FG 1 10 PWM FG RT 1 12 R PROG FG3 SEL 2 9 EP R PWM 11 2 PROG EP 11 V V BIAS 3 8 DD 17 FG3 SEL V 3 10 BIAS 4 7 OUT3 OUT1 OUT2 V 4 9 DD OUT2 5 6 GND 567 8 Note: The DIR, SS and RT pins that are not available on UDFN-10 Package are internally pulled down. SR1 and SR2 are connected by a fixed internal resistor (25 k ). *Includes Exposed Thermal Pad (EP) see Table 3-1. Functional Block Diagram V RT SS DIR BIAS V DD FG OUT3 OUT2 OUT1 PWM CPU + Peripherals FG3 SEL GND Motor Phase Detection Circuit Nonvolatile SR1 Thermal Slew Rate Memory Protection Control SR2 Adjustable K M Overcurrent Short-Circuit R PROG R Sense PROG Protection Protection DS20005359A-page 2 2015 Microchip Technology Inc. Output Drive Circuit GND DIR OUT1 SR1 GND SR2 OUT3 SS