BA6870S

Motor driver ICs 3-phase motor driver BA6870S The BA6870S is a 3-phase, full-wave, pseudo-linear motor driver suited for VCR capstan motors. The IC has a torque ripple cancellation circuit to reduce wow and flutter, and an output transistor saturation prevention circuit that provides superb motor control over a wide range of current. The built-in motor power series regulator allows applications with low power consumption. FApplications 3-phase VCR capstan motors FFeatures 1) 3-phase, full-wave, pseudo-linear driver system. 2) High performance torque ripple cancellation circuit. 3) Reversal braking by detecting the motor direction. 4) Saturation prevention circuit for high- and low-side output transistors. FAbsolute maximum ratings (Ta = 25_C) 5) Motor power supply series regulators. 6) Built-in circuit for output-to-GND short-circuit detection. FRecommended operating conditions (Ta = 25_C) 666 Motor driver ICs FBlock diagram BA6870S 667 Motor driver ICs FPin descriptions BA6870S FElectrical characteristics (unless otherwise noted, Ta = 25_C, VCC1 = 5V, VM = VCC2 = 12V) FCircuit operation (1) Pseudo-linear output and torque ripple cancellation The IC generates a trapezoidal (pseudo-linear) output current, whose waveform phase is 30 degrees ahead of that of the Hall input voltage (Fig. 1). The trapezoidal waveform of output current would create intermittence in the magnetic field generated by the 3-phase motor, and would result in an irregular rotation of the motor....