Optical disc ICs 4-channel BTL driver for CD players BA6797FP / BA6797FM The BA6797FP and BA6797FM are 4-channel BTL power drivers for CD players and each have an internal 5V regulator (requires attached PNP transistor). Because the input stage of each driver channel connects to an operational amplifier, and there are both positive and negative input pins, making these ICs adaptable for a wide range of inputs and greatly simplify filter configuration. 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) 4-channel BTL driver in a HSOP 28-pin power package, ideal for application miniaturization. 2) Wide dynamic range. 3) Internal thermal shutdown circuit. Absolute maximum ratings (Ta = 25C) Recommended operating conditions (Ta = 25C) 364 4) Internal level shifting circuit reduces the number of external components. 5) Dual positive and negative input pins, for adaptability for a wide range of inputs (including negative phase input). Also simplifies filter configuration. Optical disc ICs BA6797FP / BA6797FM Block diagram 365 Optical disc ICs Pin descriptions 366 BA6797FP / BA6797FM Optical disc ICs BA6797FP / BA6797FM Input / output circuits 367 Optical disc ICs BA6797FP / BA6797FM Electrical characteristics (unless otherwise noted, Ta = 25C, VCC = 8V, f = 1kHz, RL = 8Ω) 368 Optical disc ICs BA6797FP / BA6797FM Measurement circuit 369 Optical disc ICs Measurement circuit switch table 370 BA6797FP / BA6797FM Optical disc ICs BA6797FP / BA6797FM Application example Operation notes (1) The BA6797FP and BA6797FM have an internal thermal shutdown circuit. Output current is muted when the chip temperature exceeds 175C (typically). (2) If the mute pin (pin 9) voltage is opened or lowered below 0.5V, the output current will be muted. Pin 15 should be pulled up above 2.0V during normal use. During muting, the output pins remain at the internal bias voltage, roughly (VCC / 2). (3) The bias pin (pin 8) is muted when lowered below 1.4V (typically). Make sure it stays above 1.6V during normal use. (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. (6) The capacitor between regulator output (pin 7) and GND also serves to prevent oscillation of the IC, so select one with good temperature characteristics. 371 Optical disc ICs Electrical characteristic curves 372 BA6797FP / BA6797FM Optical disc ICs BA6797FP / BA6797FM External dimensions (Units: mm) 373