Optical disc ICs 4-channel BTL driver for CD players BA6997FP / BA6997FM The BA6997FP and BA6997FM, both designed for CD players, have an internal 4-channel BTL driver and 5V regulator (which requires attached PNP transistor), as well as switches for the 5V regulator and temperature monitor pins. Applications CD players and other optical disc devices Features 1) 4-channel BTL driver for CD players. 2) Wide dynamic range. 3) Internal thermal shutdown circuit. 4) Internal level shift circuit, for a minimum of attached components. 5) Internal 5V regular with switch. Absolute maximum ratings (Ta = 25C) Recommended operating conditions (Ta = 25C) 403 Optical disc ICs Block diagram 404 BA6997FP/BA6997FM Optical disc ICs BA6997FP/BA6997FM Pin descriptions 405 Optical disc ICs BA6997FP/BA6997FM Electrical characteristics (unless otherwise noted, Ta = 25C, VCC = 8V, f = 1kHz, RL = 8Ω) 406 Optical disc ICs BA6997FP/BA6997FM Application example 407 Optical disc ICs Operation notes (1) The BA6997FP and BA6997FM have an internal thermal shutdown circuit. Output current is muted when the chip temperature exceeds 175C (typically). (2) The output current can be muted by opening the mute pin (pin 9) voltage or lowering it below 0.5V. This pin should be pulled up above 2.0V during normal operation. When muting occurs, the output pins output the internal bias voltage, roughly VCC / 2. (3) The regulator can be turned off by opening the regulator switch (pin 10) or lowering it below 0.5V. This pin should be pulled up above 2.0V during normal operation. (4) Muting also occurs when the bias pin (8 pin) voltage drops below 1.4V (typically). This pin should stay above 1.6V during normal operation. (5) Attach a bypass capacitor (roughly 0.1µF) to the power supply, at the base of the IC. (6) Be sure to connect the radiating fin to an external ground. Electrical characteristic curves 408 BA6997FP/BA6997FM (7) The capacitor between regulator output (pin 6) and REGGND (pin 7) also serves to prevent oscillation of the IC, so select one with good temperature characteristics. (8) We recommend 2SB1132 as the PNP transistor to attach to the regulator. (9) The internal circuitry of the temperature monitor pin is shown in the diagram below. Note that the internal reference voltage is also used for the 5V regulator, which will cease to operate normally when the temperature monitor pin emits a current exceeding the regulator’s capacity. Set I to several dozen µA. Optical disc ICs BA6997FP/BA6997FM External dimensions (Units: mm) 409