269
Optical disc ICs
4-channel BTL driver for CD player
and CD-ROM drives
BA5921FP
The BA5921FP is an IC with an internal 4-channel BTL driver for CD players and CD-ROM driver actuators and motors,
as well as an internal standard operational amplifier . In addition, the 28-pin HSOP package allows for application minia-
turization.
Applications
CD players, CD-ROM drives
Features
1) 4-channel BTL driver.
2) HSOP 28-pin power package allows for application
miniaturization.
3) Wide dynamic range. (typically 3.6V when VCC = 5V
and RL = 8Ω)
4) Internal thermal shutdown circuit.
5) Gain is adjustable with an attached resistor.
6) Internal standard operational amplifier.
7) Output current is mutable with an external mute pin.
Absolute maximum ratings (Ta = 25C)
Recommended operating conditions (Ta = 25C)
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Optical disc ICs BA5921FP
Block diagram
Pin descriptions
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Optical disc ICs BA5921FP
Pin equivalent circuit diagrams
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Optical disc ICs BA5921FP
Electrical characteristics (unless otherwise noted, Ta = 25C, VCC = 5V, BIAS = 2.5V, RL = 8Ω)
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Optical disc ICs BA5921FP
Measurement circuit
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Optical disc ICs BA5921FP
Measurement circuit switch table
(1) Driver (OPIN1, NF1, OPRL1, VOPIN = 2.5V)
(2) Operational amplifier (RLOFF)
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Optical disc ICs BA5921FP
Application example
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Optical disc ICs BA5921FP
Operation notes
(1) The BA5921FP has a thermal shutdown circuit.
The output current is muted when the chip temperature
rises above 175C (typically). When the chip tempera-
ture falls to 150C (typically), the driver circuit starts up
again.
(2) The output current can be muted by opening the
mute pin (pin 9) or lowering it below 0.5V . During ordinary
use, pin 9 should be pulled up above 2.0V.
(3) Muting also occurs when the bias pin (pin 2) drops
below 1.4V (typically). Make sure it stays above 1.7V dur-
ing normal use.
(4) The internal circuits turn off when the supply volt-
age drops below 3.8V (typically), and turn on again when
it rises above 4.0V (typically).
(5) Muting occurs during thermal shutdown, mute-on
operations or a drop in the bias pin voltage or supply volt-
age. In each case, only the drivers are muted. During
muting, the output pins remain at the internal bias volt-
age, roughly (VCCVF)/2.
(6) Connect the IC to a 0.1µF bypass capacitor be-
tween power supplies, at the base of the IC.
(7) The radiating fin is connected to the package’s in-
ternal GND, but should also be connected to an external
ground.
Electrical characteristic curves
External dimensions (Units: mm)
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Optical disc ICs BA5921FP
