Rohm BA6892FP 4-channel h-bridge type btl driver for cd player Datasheet

Optical disc ICs
4-channel H-bridge type BTL driver for
CD players
BA6892FP
The BA6892FP is a 4-channel H-bridge BTL driver for CD players. Independent power supplies for each predriver and
power driver assure efficient operation at low voltages. Each channel is independently mutable.
Applications
CD players, CD-ROM drives and other optical disc devices
Features
1) 4-channel BTL driver in a HSOP 28-pin package,
ideal for application miniaturization.
2) Wide dynamic range.
3) Driver gain is adjustable with an attached resistor.
4) Independent power supply for each preamplifier and
power amplifier, for drives that operate efficiently on
low voltages.
5) Power amplifier current drops to an extremely low
level when the preamplifier power supply is lowered,
allowing for a standby mode.
Absolute maximum ratings (Ta = 25C)
Recommended operating conditions (Ta = 25C)
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Block diagram
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BA6892FP
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BA6892FP
Pin descriptions
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Input / output circuits
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BA6892FP
Optical disc ICs
BA6892FP
Electrical characteristics (unless otherwise noted, Ta = 25C, VCCPRE = VCCPOW = 4V, BIAS = 2V, RL = 8Ω,
RIN = 9.1kΩ)
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Measurement circuit
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BA6892FP
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BA6892FP
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Application example
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BA6892FP
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Operation notes
(1) The BA6892FP has an internal thermal shutdown
circuit. Output current is muted when the chip temperature exceeds 175C (typically) and restored when the
chip temperature falls to 150C (typically).
(2) The mute pin operates normally when open and at
the LOW level (below 0.5V), but mutes the output when
raised to the HIGH level (above 2V). A high impedance
is output during muting. The mute pin functions independently for each channel.
(3) Dead zone width is determined as follows:
Dead zone width = input resistance (attached resistor +
BA6892FP
internal input resistor 1kΩ) 0.2µA
Dead zone width various according to the gain setting as
defined in the preceding equation.
Example: When attached input resistor = 9.1kΩ, VDB =
(9.1k+1k) 0.2µ 2mV
Output pins output high impedance in a dead zone equal
to AmV (total for positive and negative).
(4) Be sure to connect the IC to a 0.1µF bypass capacitor to the power supply, at the base of the IC.
(5) Connect the radiating fin to an external ground.
Electrical characteristic curves
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Optical disc ICs
External dimensions (Units: mm)
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BA6892FP
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