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4-channel BTL driver for CD players

BA6897S / BA6897FP

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4-channel BTL driver for CD players
BA6897S / BA6897FP
The BA6897S and BA6897FP are a 4-channel BTL driver for CD player motors and actuators. It has an internal 5V regulator and standard operational amplifier, and is suited to a wide range of applications. FApplications CD players, CD-ROM drives FFeatures 1) Minimal number of external components. 2) Driver gain is adjustable with just one attached resistor. 3) Internal 5V regulator (attached PNP transistor necessary).
4) Internal standard operational amplifier. 5) Internal thermal shutdown circuit.
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FBlock diagram
BA6897S / BA6897FP
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FPin descriptions BA6897S
BA6897S / BA6897FP
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BA6897FP
BA6897S / BA6897FP
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FInput / output circuits
BA6897S / BA6897FP
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BA6897S / BA6897FP
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FMeasruement circuit (BA6897S)
BA6897S / BA6897FP
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FCircuit operation (1) Driver Inputs to the IC are the focus tracking error signal from the servo preamplifier and the control signal from the motor.
BA6897S / BA6897FP
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 signal centering on the internal reference voltage. Two systems (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 reference voltage internally. A PNP low saturation transistor must be connected.
(3) Amplifier General 4558 type.
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FApplication examples
BA6897S / BA6897FP
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BA6897S / BA6897FP
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BA6897S / BA6897FP
age. In each case, only the drivers are muted. During muting, the output pins remain at the internal bias voltage, roughly (VCC-VF) / 2. (5) Be sure to connect the IC to a 0.1µF bypass capacitor to the power supply, at the base of the IC. (6) The radiating fin is connected to the packages internal GND, but should also be connected to an external ground. (7) The capacitor between regulator output (pin 6) and GND also serves to prevent oscillation of the IC, so select one with good temperature characteristics.
FElectrical characteristic curves
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BA6897S / BA6897FP
FExternal dimensions (Units: mm)