BA6892FP

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. FApplications CD players, CD-ROM drives and other optical disc devices FFeatures 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. FAbsolute maximum ratings (Ta = 25_C) FRecommended operating conditions (Ta = 25_C) 445 Optical disc ICs FBlock diagram BA6892FP 446 Optical disc ICs FPin descriptions BA6892FP 447 Optical disc ICs FInput / output circuits BA6892FP 448 Optical disc ICs BA6892FP FElectrical characteristics (unless otherwise noted, Ta = 25_C, VCCPRE = VCCPOW = 4V, BIAS = 2V, RL = 8Ω, RIN = 9.1kΩ) 449 Optical disc ICs FMeasurement circuit BA6892FP 450 Optical disc ICs BA6892FP 451 Optical disc ICs FApplication example BA6892FP 452 Optical disc ICs FOperation notes (1) The BA6892FP has an internal thermal shutdown circuit. Output current is muted when the chip temperature exceeds 175_C (typically) and restored when the chip temperature falls to 150_C (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 + FElectrical characteristic curves 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. 453 Optical disc ICs FExternal dimensions (Units: mm) BA6892FP 454