A4941

A4941 Three-Phase Sensorless Fan Driver Features and Benefits Sensorless (no Hall sensors required) Soft switching for reduced audible noise Minimal external components PWM speed input FG speed output Low power standby mode Lock detection Optional overcurrent protection Variant A automotive qualified to AEC-Q100 Grade 2 Description The A4941 three-phase motor driver incorporates BEMF sensing to eliminate the requirement for Hall sensors in fan applications. A pulse wave modulated (PWM) input is provided to control motor speed, allowing system cost savings by eliminating external variable power supply. PWM input can also be used as an on/off switch to disable motor operation and place the IC into a low power standby mode. The A4941 is provided in a 16-pin TSSOP package (suffix LP) with an exposed thermal pad. It is lead (Pb) free, with 100% matte tin leadframe plating. Package: 16-pin TSSOP with exposed thermal pad (suffix LP) Not to scale Functional Block Diagram 12 V VCP VBB 10 μF SLEW PWM 25 kHz OSC VBB O/C FC TEST Startup OSC Adaptive Commutation Delay FCOM Sequencer (Direction) GND Timers OCP SENSE 0.167 Ω +VINT OUTA Soft Switch Control Logic 3-Phase Half Bridges OUTB OUTC M 0.1 μF CP1 Charge Pump 0.1 μF CP2 CTAP + OUTA CDCOM 10 kΩ FG BEMF Comparator A4941-DS, Rev. 4 + + – – – OUTB GND OUTC A4941 Selection Guide Part Number A4941GLPTR-T A4941GLPTR-A-T Three-Phase Sensorless Fan Driver Application Commerical/Industrial Automotive Packing 4...