Optical disc ICs 5-channel BTL driver for CD players BA6795FP The BA6795FP is a 5-channel BTL power driver for CD players and has an internal 5V regulator (attached PNP transistor required). The loading and spindle motor output pins are dual-use output pins and are switched between drivers using a control input. In addition, the internal level shifting circuit reduces the number of external components. Applications CD players, CD-ROM drives and other optical disc devices Features 1) 5-channel BTL driver in a HSOP 28-pin package, ideal for application miniaturization. 2) Internal level shifting circuit reduces the number of external components. Absolute maximum ratings (Ta = 25C) Recommended operating conditions (Ta = 25C) 472 3) Gain is adjustable with an attached resistor. 4) Internal thermal shutdown circuit. 5) Internal 5V regulator. (attached PNP transistor required) Optical disc ICs BA6795FP Block diagram 473 Optical disc ICs Pin descriptions 474 BA6795FP Optical disc ICs BA6795FP Electrical characteristics (unless otherwise noted, Ta = 25C, VCC = 8V, f = 1kHz, RL = 8Ω) 475 Optical disc ICs Measruement circuit 476 BA6795FP Optical disc ICs BA6795FP Measruement circuit switch table 477 Optical disc ICs Circuit operation (1) Switching between spindle and loading motor driver output modes (VCC = 8V) 478 BA6795FP Optical disc ICs BA6795FP Circuit operation (2) Loading motor driver voltage setting (forward mode) 479 Optical disc ICs Application example 480 BA6795FP Optical disc ICs Operation notes (1) The BA6795FP has an internal thermal shutdown circuit. Output current is muted when the chip temperature exceeds 175C (typically). (2) If the mute pin (pin 7) voltage is opened or lowered below 0.5V, the output current will be muted. Pin 7 should be pulled up above 2.0V during normal use. (3) The bias pin (pin 23) is muted when lowered below 1.4V (typically). Make sure it stays above 1.6V during normal use. (4) Muting occurs during thermal shutdown, mute-on operations or a drop in the bias pin voltage or supply voltage. In each case, only the drivers are muted. During muting, the output pins remain at the internal bias voltage, roughly (VCC–VF) / 2. BA6795FP (5) The driver circuit shuts down when the supply voltage drops below 4.3V (typically), and starts up again when the voltage rises above 4.5V (typically). (6) Fluctuation due to temperature occurs in the gain when using an attached resistor as the input resistor for a driver other than the spindle driver (typically 2200ppm per degree) or for the spindle driver (typically 4600ppm per degree. (Only when using the gain adjustment pin.) (7) Be sure to connect the IC to a 0.1µF bypass capacitor to the power supply, at the base of the IC. (8) The radiating fin is connected to the package’s internal GND, but should also be connected to an external ground. (9) The capacitor between regulator output (pin 6) and GND also serves to prevent oscillation of the IC, so select one with good temperature characteristics. Electrical characteristic curves 481 Optical disc ICs External dimensions (Units: mm) 482 BA6795FP