Optical disc ICs
4-channel BTL driver for CD players
BA6392FP
The BA6392FP is a 4-channel BTL driver for CD player motors and actuators. It has an internal primary filter, and can
be directly connected (without attached components) to the servo PWM output of all drivers other than the spindle driver.
The BA6392FP is pin compatible with the BA6297AFP.
FApplications
CD players, CD-ROM drives
FFeatures
1) HSOP 28-pin package allows for miniaturization of
applications.
2) PWM input is filtered by the internal primary filter,
eliminating the need for attached resistors and ca-
pacitors, thereby helping reduce the number of com-
ponents. Resistor and capacitor time constants can
also be changed with attached components.
3) Internal thermal shutdown circuit.
4) Internal mute circuit.
FAbsolute
maximum ratings (Ta = 25_C)
FRecommended
operating conditions (Ta = 25_C)
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Optical disc ICs
FBlock
diagram
BA6392FP
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Optical disc ICs
FPin
descriptions
BA6392FP
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Optical disc ICs
FElectrical
characteristics (unless otherwise noted, Ta = 25_C, V
CC
= 8V, f = 1kHz, R
L
= 8Ω)
BA6392FP
327
Optical disc ICs
FInput
/ output circuits
BA6392FP
FCircuit
operation
(1) Fig. 3 shows the inputs from the digital servo IC for
CH1-CH3 drivers (all drivers except the spindle).
SW1 is on when the forward input signal (HIGH level,
over 2.4V) is present. SW2 is on when the reverse input
signal is present (Fig. 2)
The constant current (I
1
) at this time enters the RC and
generates an integral waveform based on the duty of the
input waveform. The BTL is output from BUF1 and BUF2
(Fig. 4).
To maintain the HIGH level with forward (or reverse) in-
put, the DC voltage generated at point A is :
I
1
R 2.5V (reverse :
*2.5V)
This is the voltage generated relative V
REF
. The setting is
such that a voltage differential of 5V is generated be-
tween output pins. The time constant is :
R
C = 2.4µsec
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