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Optical disc ICs BA6896FP
Circuit operation
(1) Driver
Inputs to the IC are the focus tracking error signal from
the servo preamplifier and the control signal from the mo-
tor. The input signals, which normally center on 2.5V, are
V / I converted by the preamplifier, generating a current
corresponding to the input voltage. This current is
passed through a resistor and into the internal reference
voltage component, the preamplifier output being a sig-
nal centering on the internal reference voltage. Two sys-
tems (positive phase and negative phase) are created
during V / I conversion, generating BTL output via the
driver buffer.
(2) Regulator
This is a typical series regulator that generates a refer-
ence voltage internally. A PNP low saturation transistor
must be connected.
(3) Operational amplifier
A standard 4558 type.
