Daewoo DV-700S, Service Manual

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6
CIRCUIT OPERATIONAL DESCRIPTION
1) Motor Drive IC: AT5868S
The AT5868S is a 5-channel BTL driver IC for driving the motors and actuators in
products such as CD-ROM/DVD-ROM/DVD-Player drives. Two of the channels use current
feedback to minimize the current phase shift caused by the influence of load inductance.
Driver IC generates the focus signal and the tracking signal for pick-up actuator, the
sled signal for feed, spindle signal and the load signal for opening and closing of the
tray. The focus signal, the tracking signal, the sled signal and the spindle signal are
input into each relaxant port of the drive IC(in the order of No. 26 pin, 23, 4, and 1)
and set the gain amplification and the center voltage through the internal OP-AMP
and drive on both sides and then the focus signal and the tracking signal will be
output as VOFC+, VOFC- and VOTK+, VOTK- on actuator, the sled signal and the
spindle signal will be output as VOSL+, VOSL- and VOLD+, VOLD- on each motor. For
the load signal the input opening/closing signal is output as VOTR+, VOTR- through
the loading PRE FWD REV circuit.
Motor Drive IC (AT5868S) Block Diagram