Optical disc ICs
4-channel BTL driver for CD players
BA6297AFP
The BA6297AFP is a 4-channel BTL driver for CD player actuators and motors. The preamplifier has both positive and
negative input pins and output pins, making this IC suited to a broad range of applications.
FApplications
CD players
FFeatures
1) 4-channel BTL driver.
2) HSOP 28-pin package allows for miniaturization of
applications.
3) Internal thermal shutdown.
4) Driver gain is adjustable with a single attached resis-
tor.
5) Both positive and negative input pins, for adaptability
for a wide range of inputs (including negative phase
input).
FAbsolute
maximum ratings (Ta = 25_C)
FRecommended
operating conditions (Ta = 25_C)
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Optical disc ICs
FCircuit
operation
The BA6297AFP comprises a 4-channel driver, internal
bias amplifier, mute pin and thermal shutdown.
(1) Driver
The driver uses a buffer to output one of the outputs from
its preamplifier with no modification, and uses an inver-
sion amplifier to invert the other output before sending it
to the driver buffer. The inversion amplifier’s reference is
the bias voltage generated internally (pin 7 voltage), and
so the preamplifier output must make the zero level equal
to the internal bias voltage. See Figs. 7 and 8 for exam-
ples.
BA6297AFP
(2) Internal bias amplifier
Configured as shown in Fig. 9. The internal bias voltage
(V
ref
) is calculated thus :
V
ref
=
V
CC
*V
F
2
(3) Mute pin (pin 15)
The output current is muted when this pin receives the
low level or a high impedance. Set the pin voltage at high
during normal operation.
(4) Thermal shutdown
The BA6297AFP has an internal thermal shutdown cir-
cuit. Output current is muted when the chip temperature
exceeds 175_C (typically).
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