Motor driver ICs 2-phase half-wave motor predriver BA6406F The BA6406F is a 2-phase, half-wave motor predriver suited for fan motors. Features 1) Lock detection and rotational speed sensing mechanisms are built in. 2) Compact 8-pin SOP package reduces the number of external components required. 3) Automatic restart when the motor lock is undone. 4) Hall inputs have a hysteresis. Absolute maximum ratings Operating power supply voltage (Ta = 25C) 695 Motor driver ICs Block diagram and application example Electrical characteristics (unless otherwise noted, Ta = 25C and VCC = 12V) 696 BA6406F Motor driver ICs BA6406F FLock detection The automatic restart circuit detects a motor lock condition and automatically turns off the output current. When the lock condition is cleared, the IC automatically restarts and allow the motor to run. In the BA6406F, automatic restart is performed in the following manner. A motor lock condition is detected when Output ON time (tON) and OFF time (tOFF) determined by the pin6 capacitor where tON = tOFF = C S (V6CLV6CP) I6C C S (V6CLV6CP) I6d (sec) the Hall signal stops switching. The output is ON when pin 6 is being charged, and OFF when pin 6 is being discharged. Pin 3 is ON during normal operation, and OFF when the motor is locked. Pin 3 is an open collector output. C is the capacitance of the pin-6 external capacitor V6CL is the pin6 clamp voltage V6CP is the pin6 comparator voltage I6C is the pin6 charge current I6d is the pin6 discharge current (sec) 697 Motor driver ICs BA6406F Operation notes (1) The lock detection output pin (pin 3) may maintain HIGH level for a few hundred milliseconds when the power is turned on. (2) Allowable power dissipation The allowable power dissipation is plotted against ambient temperature in Fig. 3. (3) Power dissipation Power consumed in the IC can be calculated from the following equation: PC = PC1+PC2+PC3 (1) PC1 is power consumed by the circuit current. PC1 = VCC ICC (2) PC2 is the output current consumption. PC2 = (VCC*VOH) IO Electrical characteristic curves 698 VOH is the HIGH level voltage of pins 7 and 8. Power dissipation can be reduced by raising the hfe-rank of the external output transistor and thereby reducing the IO value. (3) PC3 is power consumed by pin 3. PC3 = V3L I3 where V3L is the pin-3 LOW level voltage and I3 is the pin-3 current. Make sure that your application does not exceed the allowable power dissipation of the IC. Motor driver ICs BA6406F External dimensions (Units: mm) 699