Optical disc ICs 4-channel BTL driver for CD players and CD-ROMs BA5970FP The BA5970FP is a 4-channel BTL driver developed to drive CD player motors and actuators. The driver input stage contains an operational amplifier, supports a variety of input formats, and allows simple configuration of a filter. FApplications CD players, CD-ROM FFeatures 1) 4-channel BTL driver. 2) Wide dynamic range (4V when PREV CC = 8V, POWVCC = 5V, and RL = 8Ω). 3) Internal thermal shutdown circuit. 4) Driver gain is adjustable with externally connected resistor. 5) Independent power supplies PREVCC, POWVCC (for channels 1 and 2), and POWVCC (for channels 3 and 4), and low voltage operation for a highly efficient drive. 6) Independent mute pins for channels 1 and 2 and channels 3 and 4. 7) Perfect for compact applications with the use of the HSOP28-pin power package. FAbsolute maximum ratings (Ta = 25_C) FRecommended operating conditions (Ta = 25_C) 653 Optical disc ICs Block diagram Pin descriptions 654 BA5970FP Optical disc ICs BA5970FP Input / output circuits 655 Optical disc ICs FElectrical characteristics (unless otherwise noted, Ta = 25_C, PREVCC = 8V, POWVCC1 = 5V, FPOWVCC2 = 8V, BIAS = 2.5V, RL = 8Ω) 656 BA5970FP Optical disc ICs BA5970FP Measurement circuit 657 Optical disc ICs Measurement circuit switch table (1) Driver block (OPB ! 1, NF ! 1, OPRL ! 1) (2) 658 Pre-stage operational amplifier block (VN1 = VM2 = 0V, RL ! OFF) BA5970FP Optical disc ICs BA5970FP Application example 659 Optical disc ICs FOperation notes (1) The BA5970FP contains a thermal shutdown circuit. When the chip temperature reaches 175_C (Typ.), the output current is muted. If the chip temperature then drops below 150_C (Typ.), then the mute is released. (2) By having the mute pin voltage pulled up to 2.0V or greater, you can mute the output current. For normal conditions, have mute pin open or at 0.5V or below. (Pin 9 mutes channels 1 and 2, and pin 20 mutes channels 3 and 4.) (3) If the voltage of the bias pin (pin 1) drops below 1.4V (Typ.), outputs are muted. For normal conditions, have the voltage above 1.7V. (4) If the power supply voltage drops below 3.8V (Typ.), FElectrical characteristic curves 660 BA5970FP internal circuits turns off. If the power supply voltage then rises to 4.0V (Typ.), the circuits turn on. (5) If the voltage of the thermal shutdown, mute ON, or bias pin drops, or if the power supply voltage drops, the mute is activated; however, in these situations, only the drivers are muted. Also, the output pin voltage becomes the internal bias voltage (approx. VCC / 2 for channels 1 and 2, and (VCC–VF) / 2 for channels 3 and 4). (6) Connect a bypass capacitor (approx. 0.1µF) between the bases of the power supply pins of this IC. (7) Even though the radiation fins are connected to ground within the package, be sure to also connect them to a ground externally as well. Optical disc ICs BA5970FP External dimensions (Units: mm) 661