LB11975 Datasheet, PDF (11/12 Pages) Sanyo Semicon Device – High-Speed CD-ROM Spindle Motor Driver IC

LB11975
(3) When both the upper and lower side transistors are switched and current detection (RF) is performed in the upper side
transistor
During reverse torque braking, when the coil current increases and the limit is reached, both the upper and lower side
transistors are turned off. The motor current circuit path at this point is as follows:
Coil → upper side diode → V_CC → power supply line capacitor → ground → lower side diode → coil
When the limiter circuit operates, both the upper and lower side transistors are turned off, so short-circuit breaking
does not occur, and coil current attenuation is all that occurs. Thus this technique allows current control at the set
(limiter) current to be performed even during reverse torque braking.
Regenerative Current Path
RF
+
–
Drive Mode
A13187
No. 6497-11/12